A Review of the Genus Cancellus

(Crustacea: Diogenidae)

with the Description of a

New Species from the Caribbean Sea

BARBARA SHULER MAYO

m

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY • NUMBER 150
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SMITHSONIA N CONTRIBUTION S TO ZOOLOG Y • NUMBE R 150

A Review of the Genus Cancellus

(Crustacea: Diogenidae)

with the Description of a

New Species from the Caribbean Sea

Barbara Shuler Mayo

SMITHSONIAN INSTITUTION PRESS

City of Washington

1973
ABSTRACT

Mayo, Barbara Shuler. A Review of the Genus Cancellus (Crustacea: Diogenidae) with the Description of a New Species from the Caribbean Sea. Smithsonian Contributions to Zoology, number 150, 63 pages, 25 figures, 1973.—

All available literature dealing with the genus Cancellus is reviewed. Of the ten

nominal species in the genus, eight are probably valid. Reports made by previous authors on the biology, ecology, and behavior of these specialized hermit

crabs are included along with new observations.

New material of six nominal species of Cancellus was examined: Cancellus

ornatus and C. spongicola from the West Indies are redescribed and illustrated.

C. calypso Forest and St. Laurent, 1967, was found to be within the range of

variation of C. ornatus and is considered a synonym. Cancellus tanneri from

the eastern Pacific is redescribed and illustrated. The morphology of the few

specimens available was practically identical to that of C. ornatus, and it appears

that the two are closely related. The eastern Atlantic species, C. parfaiti, is

redescribed and figured; it seems to be closely related to C. spongicola. Cancellus

typus, the Australian species, is redescribed and illustrated. Although distinct,

it has several characters in common with C. parfaiti. The holotype of Cancellus

canaliculatus (Herbst) from the "east Indies" is redescribed and illustrated. It

is generally similar to C. parfaiti, but can be distinguished easily. A specimen

of C. investigatoris from Japanese waters is redescribed and illustrated. This

species, also known from Indian coasts, is similar to C. parfaiti as noted by

Alcock (1905), and is distinct from C. canaliculatus. Cancellus macrothrix, the

aberrant species from South Africa, is reviewed. It shows characters which may

be more primitive and more typically diogenid than those of the other species.

Cancellus viridis, a new species from the Caribbean, is described and figured.

Its morphology is much like that of C. ornatus. This species brings the total

number in the genus to nine if the aberrant C. macrothrix is included. A key

to all described species is given.

OFFICIAL FI'BUCATION DATE is handstamped in a limited number of initial copies and is recorded

in the Institution's annual report, Smithsonian Year, SI PRESS NUMBER 4804. SERIES COVER DESIGN:

The coral Montastrea cavernosa (Linnaeus).

Library of Congress Cataloging in Publication Data

Mayo, Barbara Shuler, 1945—

A review of the genus Cancellus (Crustacea: Diogenidae)

(Smithsonian contributions to zoology, no. 150)

1. Cancellus. 2. Cancellus viridis. I- Title. II. Series: Smithsonian Institution. Smithsonian

contributions to zoology, no. 150.

QL1.S54 no. 150 [QL444.M33] 591'.08s [595'3844] 73-296

For sale by the Superintendent of Documents, U.S. Government Printing Office,

Washington, D.C. 20402 - Price: $1.50, domestic postpaid; $1.25, GPO Bookstore
Contents

Page

Introduction 1

Acknowledgments . 1

Literature Review 2

Materials and Methods 4

Classification 5

Family DIOGENIDAE Ortmann, 1892 5

Genus Cancellus H. Milne Edwards, 1836 6

Key to Species of Cancellus 11

1. Cancellus spongicola Benedict, 1901 12

2. Cancellus ornatus Benedict, 1901 18

3. Cancellus viridis, new species 28

4. Cancellus tanneri Faxon, 1893 33

5. Cancellus parfaiti A. Milne Edwards and Bouvier, 1891 ... . 38

6. Cancellus typus H. Milne Edwards, 1836 44

7. Cancellus canaliculatus (Herbst, 1804) 50

8. Cancellus investigatoris Alcock, 1905 54

9. Cancellus macrothrix Stebbing, 1924 60

Literature Cited 61

A Review of the Genus Cancellus

(Crustacea: Diogenidae)

with the Description of a

New Species from the Caribbean Sea

Barbara Shuler Mayo

Introduction

Cancellus is a distinctive genus of hermit crabs

in the family Diogenidae. Most animals of this

genus live in pieces of rock, sponge, coral, or other

firm substances, rather than in gastropod shells as

is more typical for pagurid crabs. When the animal withdraws within the generally cylindrical cavity, the aperture is closed by an operculum formed

by the modified chelipeds and anterior ambulatory

legs.

Species have been listed in Alcock's catalogue of

the Indian decapod crustaceans (1905) and in Gordan's bibliography (1956), but no review of the

genus has been attempted previously. With the

new material available, it is now possible to redescribe the western Atlantic species. Material of all

known species, except Cancellus macrothrix, has

been made available for study. This paper brings

together and summarizes all work done to date

on each of the nominal species. The synonymies

are complete with the possible exception of Cancellus typus, the Australian species, which has an

extensive popular literature.

Barbara Shuler Mayo, Rosenstiel School of Marine and

Atmospheric Science, University of Miami, Miami, Florida

33149.

ACKNOWLEDGMENTS.—Because of the sparsity and

widespread distribution of the animals studied, I

was dependent on many sources for specimens. I

would like to thank the following for making material available: Dr. Des Griffin of the Australian

Museum, Sydney; Dr. R. B. Manning of the National Museum of Natural History, Washington,

D.C.; Dr. H. W. Levi of the Museum of Comparative Zoology, Cambridge, Massachusetts; Dr. H. E.

Gruner of the Zoologisches Museum, Berlin; Mr.

John Garth of the Allan Hancock Foundation, Los

Angeles; Mr. David Camp of the Florida Department of Natural Resources, St. Petersburg; Dr. Roy

01erod of the Naturhistoriska Riksmuseum, Stockholm; and Dr. S. Miyake of Kyushu University,

Fukuoka, Japan.

I am deeply indebted to Dr. Anthony J. Provenzano for initially suggesting the problem, directing

the research, and reviewing the manuscript.

I wish to thank Dr. Frederick M. Bayer for his

many valuable recommendations and criticisms

concerning illustrations and taxonomic problems,

and for reviewing the manuscript.

I am especially grateful to the members of my

master's thesis committee: Drs. A. J. Provenzano,

Donald R. Moore, Durbin C. Tabb, and Lowell

P. Thomas.

The advice and opinions offered by Dr. L. B.

1
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Holthuis regarding taxonomic questions are appreciated. I also thank Dr. Holthuis, Dr. Gilbert Voss,

Dr. Jacques Forest, Miss Janet Haig, and Mrs.

Patsy MacLaughlin tor critically reviewing the

manuscript. In addition, I owe thanks to Miss

Barbara Stolen for her excellent drawings of some

type-material not available to me. I thank Mrs.

Eva-Maria Kiene for verifying my translations from

German. Mr. Charles Mayo assisted me in photographing some of the specimens for study and read

parts of the manuscript.

During the period of this study, I was supported

by a Robert E. Maytag Fellowship and a University of Miami Fellowship.

This study was supported in part by research

grant GB-7075X from the National Science Foundation; ship time during the collecting cruises of

the R/V Pillsbury and R/V Gerda was paid for by

National Science Foundation research grants GP1363, GB-2204, GB-3808, GB-5776, GB-7082, and

GA—4569; some of the material was collected during cruises of the National Geographic SocietyUniversity of Miami Deep-Sea Biology Program.

This study is Scientific Contribution No. 1617

from the Rosenstiel School of Marine and Atmospheric Science.

Finally, I want to acknowledge with deep gratitude the support always provided by my parents.

LITERATURE REVIEW.—The first description of a

species recognized today as belonging in the genus

Cancellus was given by J. F. W. Herbst in 1804.

According to his brief and very general note, the

carapace of Cancer canaliculatus from the "East

Indies" was "as usual" but the animal could be

distinguished from all other crabs by the "claws."

While there is no question that this was a Cancellus, neither the illustration nor the description

was sufficiently detailed to permit specific identification. The holotype is redescribed and illustrated in this paper.

Olivier (1811) moved Herbst's Cancer canaliculatus to the genus Pagurus and stated that the animal was found on the "coasts of the Indian Ocean."

His encyclopedic treatment of the species seemed

to be based solely on Herbst's work rather than on

any additional material.

H. Milne Edwards (1836) formally established

the genus Cancellus as separate from other genera

in the tribe "Paguriens"; the distinguishing features were the symmetry of the abdomen and the

lack of appendages between the thorax and the

last abdominal segment. He described and figured

one male from an unknown location as Cancellus

typus and pointed out that Pagurus canaliculatus

figured by Herbst appeared to be close to his new

species.

H. Milne Edwards included a description of the

genus Cancellus and the species C. typus in his

Histoire Naturelle des Crustace's, published in

1837. This report contained the same information

presented previously (1836), and referred to the

single male specimen.

Dana (1852) divided the Paguridea into two

families: the Paguridae and the Cenobitidae. He

proposed the further division of the Paguridae into

two subfamilies based on the structure of the abdomen: the asymmetrical Pagurinae, which included the genus Pagurus and four new genera

(Bernhardus, Calcinus, Diogenes, and Paguristes);

and the symmetrical Cancellinae, with the single

genus Cancellus.

This classification was repeated in another paper in 1852 in which Dana added several genera

td the Pagurinae, while Cancellus remained the

only genus in Cancellinae.

Zietz read a paper to the Royal Society of South

Australia in 1887, describing Gryllopagurus lithodomus from St. Vincent Gulf as a new genus and

species. The description and figures were published in 1888.

Cancellus typus was included in a list of the

fauna of Port Jackson (near Sydney, New South

Wales, Australia) compiled by Whitelegge in 1889.

In a paper on Scyllarus sculptus, Whitelegge

(1889) briefly mentioned Cancellus typus, pointing

out that it had been described without a definite

habitat but had subsequently been found in South

Australia and in Port Jackson.

A. Milne Edwards and Bouvier published a paper in 1891 dealing with hermit crabs of the genus

Cancellus. They described a new species, Cancellus parfaiti, from the Cape Verde Islands. They

remarked on the use of the chelipeds and ambulatory legs as an "operculum" for the dwelling of

the crab. Moreover, they pointed out the similarities and differences between Cancellus and the

other pagurids, and defined the relationship of

Cancellus to the superficially similar Pylocheles.

The characters used to distinguish C. parfaiti from

C. typus were listed. Cancer canaliculatus Herbst
NUMBER 150

was formally placed in the genus Cancellus, and

note was made of the characters, according to

Herbst's description and figure, which served to

separate it from the closely related C. typus. Finally, they stated that Cancellus was composed of

three species: C. typus H. Milne Edwards, C. canaliculatus (Herbst), and C. parfaiti. Apparently

they had no knowledge of Zietz's Gryllopagurus

Uthodomus from Australia. C. parfaiti was mentioned in a preliminary note on the hermit crabs

collected from the Travailleur and Talisman, published by A. Milne Edwards and Bouvier in 1892.

This note concerned the same animals reported in

1891, but indicated that the species had been collected by Parfait at Annobon and at lie du Prince.

Perrier (1893) reported the occurrence of C. parfaiti off Senegal, but it is not known whether this

was a new location or simply a restatement of a

previous report.

A. Milne Edwards (1893) referred to Cancellus

in the report of the Blake pagurids, again pointing

out that the similarities between Cancellus and

Pylocheles were due only to adaptations to a similar mode of life.

The same year, Faxon (1893) gave a preliminary

description of a new species, Cancellus tanneri,

from the Gulf of Panama. The complete description, accompanied by several figures, appeared in

1895. He reviewed the literature and summarized

the characters that could be used to distinguish

C. tanneri from the three species discussed by A.

Milne Edwards and Bouvier (1891).

In the scientific results of the Travailleur and

Talisman, A. Milne Edwards and Bouvier (1900)

redescribed and figured Cancellus parfaiti. Their

description and figures were the most detailed and

specific for any species in the genus at that time.

They distinguished C. parfaiti from the three other

Cancellus known to them, and stated that their

specimens, collected by Commandant Parfait, came

from "ile du Prince (lies du Cap-Vert) et Annobon."

Benedict (1901) added two new species to the

genus Cancellus in a rather short publication on

new symmetrical hermit crabs from the West Indies dredged by the Albatross in 1885. Cancellus

ornatus was described from a single female from

the Gulf of Mexico, and C. spongicola from one

male taken in the vicinity of Arrowsmith Bank in

the Caribbean. The descriptions are brief and incomplete, and the few figures are nonspecific.

Sayce recorded Cancellus typus in a report of the

results of dredging at Port Phillip in Australia in

1902. He gave the crab the common name of

"boring hermit."

In 1905, the pagurid part of Alcock's monograph

of the Indian decapod crustaceans was published.

This volume dealt with the Paguridea, including

the families Pylochelidae, Paguridae, Coenobitidae, and Lithodidae. A worldwide key to the recognized genera of each family was given, and

Cancellus was included in the Paguridae. Alcock

listed Gryllopagurus as a synonym of Cancellus and

gave a description of the genus. He described

Cancellus investigatoris from off the coast of Ceylon as a new species extremely similar to C. parfaiti A. Milne Edwards and Bouvier. A very useful

table of the genera and species of pagurids appears

at the end of Alcock's publication. It includes

the pertinent references for each species and the

approximate depth range from which they were

reported. He listed eight species of Cancellus: C.

canaliculatus (Herbst), C. investigatoris Alcock, C.

typus Milne Edwards, C. tanneri Faxon, C. ornatus

Benedict, C. spongicola Benedict, C. parfaiti A.

Milne Edwards and Bouvier, and C. Uthodomus

Zietz.

Southwell (1906) reported one specimen of C.

investigatoris from the Indian Ocean in Herdman's

Report to the Government of Ceylon on the Pearl

Oyster Fisheries of the Gulf of Manaar [sic, =

Mannar]. Later (1910), he noted and figured,

among other things, the coralline "habitaculum"

or dwelling of a specimen of C. investigatoris.

In 1921, Balss reported a new location for C.

parfaiti off Angola, based upon a single ovigerous

female.

Cancellus macrothrix was described by Stebbing

in 1924. According to Barnard (1950), "it is difficult to extract any specific characters from Stebbing's description and figures." The type-specimen

came from Algoa Bay, near Port Elizabeth on the

southeastern coast of South Africa.

"The Crustaceans of South Australia, Part 1,"

by Hale was published in 1927. This volume, one

of the Handbooks of the Fauna and Flora of South

Australia, was a general reference written in a popular style with many photographs and nontechnical

descriptions. Cancellus typus was briefly described

under the common name of miner hermit crab.
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

In British, Australian and New Zealand Antarctic Expedition 1929-1931 Reports, Hale (1941) described and figured the early stage of Cancellus

typus. He included Gryllopagurus lithodomus in

the synonymy, and commented that Zietz's material

was dried and the eviscerated types filled with cotton wool.

In the same year, Rabaud (1941) mentioned C.

parfaiti in a paper on pagurid adaptations.

Two popular accounts of C. typus appeared in

1944 and 1947 by Elizabeth Pope in Australian

Museum publications. She commented that the

crab lives in a hole in a stone, rather than in a

snail shell like most other hermits.

In 1950, Barnard compiled a new description of

Cancellus macrothrix Stebbing, the South African

species, unreported since the original description

in 1924. One of his specimens was from Algoa Bay,

the type-locality; the other two were taken off East

London and Cape Morgan. He commented on several "glaucothoes" which had been collected with

one of the female specimens.

Dakin (1952) mentioned Cancellus typus in his

popular book, Australian Seashores, and included

two photographs of the crab.

A year later, Pope (1953) wrote a magazine article about Cancellus typus. She told of Zietz's

animals from St. Vincent Gulf and reported subsequent locations: in other parts of South Australia; Western Port, Port Phillip, and off Cape

Everard in Victoria; and in Sydney Harbour and

Port Jackson in New South Wales. "A Cancellus

boring into a stony polyzoan colony" collected from

the F.I.S. Endeavour off Devonport, Tasmania, was

reported in her paper; this specimen was among

the material examined in the present study.

In 1956, Balss wrote that the genus Cancellus,

with its "stretched out" abdomen, was composed

of nine species, circumtropically distributed in the

littoral zone, and that they lived in coral rocks, in

hollowed-out rocks, or in sponges. He used Hale's

(1927) photograph showing C. typus ensconced in

a fragment of rock.

In the introductory section of the scientific results of the Calypso expeditions, Forest (1959) mentioned Cancellus parfaiti taken on a cruise in the

Gulf of Guinea in 1956.

Two years later, in an Atlantide report, Forest

(1961) reported three specimens of C. parfaiti

taken by the Galathea near Sao Tom6 in 1950. In

addition, he reported having collected many C.

parfaiti off the coast of Dakar in 1953.

In 1966, Forest formally reported the three specimens of C. parfaiti collected by the Calypso near

Sao Tome in 1956.

The most recently described species was Cancellus calypso Forest and St. Laurent (1967). The

description was based on one female specimen

taken in a colony of bryozoans near the island of

Abrolhos off the coast of Brazil. The very detailed

description and clear figures are the most precise

given for any animal in this genus. Forest and St.

Laurent pointed out that the species was very close

to C. ornatus Benedict. Diagnoses of the family

Diogenidae and the genus Cancellus and a key to

the genera of the western Atlantic diogenids were

included in their paper.

The only behavioral study of a Cancellus was

done by Hazlett (1969). He reported the "stone

fighting" behavior of several specimens of Cancellus spongicola observed in the laboratory, and

compared it to that of other diogenids.

MATERIALS AND METHODS.—Most specimens examined in this study were taken during oceanographic cruises of the research vessels John Elliott

Pillsbury and Gerda of the Rosenstiel School of

Marine and Atmospheric Science, University of

Miami, Florida. The letters P and G in station

numbers refer to the Pillsbury and Gerda stations,

respectively. A few specimens were collected

from the M/V Silver Bay and the M/V Oregon

of the U.S. Fish and Wildlife Service, Pascagoula, Mississippi. The type-specimens of Cancellus ornatus and C. spongicola were borrowed

from the National Museum of Natural History,

Washington, D.C.; illustrations and photographs

of these were made for study and comparison.

The holotype of Cancellus canaliculatus was

borrowed from the Zoologisches Museum, Berlin. Camera lucida sketches for study of the typespecimens of C. tanneri from the Museum of

Comparative Zoology, Harvard College, Cambridge, were made by Miss Barbara Stolen. One of

the two specimens of C. tanneri available was obtained from the Allan Hancock Foundation, Los

Angeles, California, and the other was borrowed

from the Naturhistoriska Riksmuseum, Stockholm.

The C. typus material was borrowed from the Australian Museum, Sydney. The specimen of C. in-
NUMBER 150

vestigatoris was borrowed from Kyushu University,

Fukuoka, Japan.

Most of the animals were captured using bottom

nets (otter trawls) or dredges and were immediately

preserved in formalin. All were subsequently transferred to ethyl alcohol. A few were placed in

ethylene glycol and ethanol. Ionol, an antioxidant

color preservative, was added in some cases, but it

was not very effective.

Some live specimens were brought into the laboratory and were maintained for several months.

Several animals produced as many as four moults

that were preserved in 10 percent buffered formalin.

The shield length, shield width, and sex were

noted for each specimen; shield length is the measurement listed in material sections unless otherwise indicated. Occasionally other measurements

were made for the purpose of comparison. Measurements were made using an ocular micrometer.

Sex determination was based on the position of

the gonopores and the presence or absence of pleopods on the abdomen. The male has gonopores on

the fifth coxal segment and lacks pleopods; the

female has gonopores on the third coxal segment

and four biramous pleopods on one side of the

abdomen. Some secondary sexual characteristics

which vary among the species are described in the

individual species accounts.

Illustrations were made with the aid of a Wild

M-5 microscope and drawing apparatus. Significant morphological features are labeled on the diagrams on Figure 1.

A list of the technical terms and abbreviations

used in the descriptions follows. The definitions

usually apply to all hermit crabs but are intended

for the genus Cancellus only.

cardiac region: the median calcined area posterior to the

cervical groove and anterior to the first abdominal segment,

cephalothoracic shield: the part of the carapace anteromedial

to the cervical groove, and anterior to the linea transversalis.

cl.: length of the carapace measured from tip of rostral

projection to transverse margin of posterior carapace

between membranous lobes.

Mxx, Mx2: maxillae; sometimes called maxilla and maxillule,

respectively.

Mxpv-Mxps: first through third maxillipedsopercular surface: the area on the dorsal (in this genus,

anterior) surface of a pereiopod contributing to the

discoidal operculum formed when the appendages are

drawn in.

Pi,: cheliped; first pereiopod.

P2, P3: ambulatory legs; second and third pereiopods.

P4, PB: fourth and fifth pereiopods.

Pli-Pl5: first through fifth pleopods.

protopod: the part of the uropod to which both the exopod

and endopod are attached.

si.: cephalothoracic shield length, measured from tip of

rostrum to linea transversalts.

sw.: shield width measured at widest part of the cephalothoracic shield.

The recently collected material was deposited

in the Division of Crustacea, National Museum of

Natural History, Smithsonian Institution (under

the collection numbers of the United States National Museum: USNM), the Rijksmuseum van

Natuurlijke Historic Leiden (RMNH), or the Invertebrate Museum, Rosenstiel School of Marine

and Atmospheric Science, Miami (UMML).

Classification

[Adapted from MacDonald, Pike and Williamson (1957),

Forest and St. Laurent (1967) and Caiman (1909)]

Phylum: ARTHROPODA.

Class: CRUSTACEA.

Subclass: MALACOSTRACA.

Order: DECAPODA.

Suborder: REPTANTIA.

Section: ANOMURA.

Superfamily: COENOBITOIDEA (= Paguridea

Serie Pagurienne Bouvier 1940).

Family: DIOGENIDAE Ortmann, 1892 (subfam.)

emend. (= subfams. Pagurinae + Diogeninae

Ortmann, 1892 = subfam. Dardaninae Schmitt,

1926).

Genus: Cancellus H. Milne Edwards, 1836.

Family DIOGENIDAE Ortmann, 1892

Fourteen pairs of gills on each side, namely: 10 arthrobranchs and one pleurobranch on P2, P3, P4, and PB. In

certain genera, 13 pairs only, pleurobranch lacking on PB.

Branchial lamellae usually undivided, sometimes divided into

two lobes.

Mxp3 approximated at base. Ischium of these appendages

with crista dentata developed or not, according to the genus,

always lacking an accessory tooth.

Chelipeds equal, subequal or very unequal; in which case,

the left is largest, except in Petrochirus.
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

antennule

antennukr peduncle

carpus

ocular peduncle

antennal acicle

ocular scale

lateral projection

rostrum

cephalothoracic shield

gastric pit

opercular surface

cervical groove

branchial region

cardiac region

dactylus

pleopod

abdomen

dactylus

endopod

protopod

telson

female gonopore

position of male

gonopore

FIGURE 1.—Generalized Cancellus, external morphology: a, dorsal view of complete animal

except pereiopods; b, cephalic appendages, lateral view; c, cheliped, lateral view; d, ambulatory

leg, lateral view; e, coxal segments, ventral view; /, tail fan. (Setae omitted.)

On the male, no paired pleopods and four unpaired pleopods (P12-P15) except in Paguristes and Paguropsis, where

PI, and PL are paired, and in Canceltus, where there are

no pleopods on somites 1 to 5.

On the female, no paired pleopods and four unpaired

pleopods (PL to Pl5) except in Paguristes and Paguropsis,

where there are paired Plj. (Translated from Forest and St.

Laurent, 1967.)

Genus Cancellus H. Milne Edwards, 1836

Cancellus H. Milne Edwards, 1836:262, 286; 1837:212, 242—

Dana, 1851:267, 269; 1852:123.—A. Milne Edwards and

Bouvier, 1891:66-70; 1892:225—Faxon, 1895:52.—Ortmann,

1898:1146.—A. Milne Edwards and Bouvier, 1900:183

Alcock, 1905:7, 11 [table], 24 [key], 76-77.—Stebbing,

1924:240.—Barnard, 1950:446-447—Balss, 1956:1392.—Gor-
NUMBER 150

dan, 1956:305 [list].—Russell, 1962:19.—Forest and St.

Laurent, 1967:67 [key], 95.

Cryllopagurus Zietz, 1888:298.

TYPE-SPECIES.—Cancellus typus H. Milne Edwards, 1836, by original designation.

DIAGNOSIS.—

Fourteen pairs of gills with undivided lamellae. Antennal

flagella short, with very short setae.

N'o lateral lobe on the endopodite of Mxj. Crista dentata

well developed on the ischium of Mxp3.

Chelipeds equal, modified, forming an operculum with the

distal articles of P2 and P3; claws corneousOn the male, no unpaired pleopods. On the female, four

large biramous unpaired pleopods, Pl2 to Pl5. Abdomen and

uropods symmetrical. (Translated from Forest and St. Laurent, 1967.)

DESCRIPTION.—Cephalothoracic shield usually

shorter than maximum shield width; laterally convex; frontal margin with inflated rim, postorbital

indentations. Anterior surface of shield sculptured,

posterior part smoother; indentations in posterolateral margins.

Cardiac region calcified, at least in part; calcification usually decreasing posteriorly. Anteromesial

part of brachial regions calcined, but most of area

submembranous.

Ocular scales broad at base; inner part projected

anteriorly to a triangle or tubercle which may

terminate in one or more teeth or spinules.

Ocular peduncles shorter than shield length; cornea inflated slightly or not inflated, with basal

emargination dorsally.

Antennular peduncle when extended approximately same length as ocular peduncle; basal segment usually armed with two or more teeth.

Antennal acicle reaching one-fourth to one-half

length of ocular peduncle, terminating in two or

more teeth distally; other teeth usually present on

outer or inner margins; basal segment deeply indented, armed distally with two heavy teeth, one

projecting anterolaterally, the other anteromesially.

Chelipeds equal, modified; dorsal surface of carpus with sharp angle, wrist flexed such that dorsal

surface of propodus and distal half of carpus are

anterior and perpendicular to the longitudinal

plane of the animal. These anterior surfaces, together with surfaces of distal segments of P2, forming discoidal operculum closing round opening of

carcinoecium. Opercular surfaces flattened or concave, usually tuberculate, often with shallow channels between rows of tubercles. Dorsal margin of

carpus at flexure often raised in distinct lobate

crest. Most surfaces on all segments of chelipeds

and P2 relatively smooth except for opercular surfaces and angular margins. Inner dorsal margins of

manus usually lobate at sharp angle separating

opercular surface from smooth, flat inner face.

Dorsolateral margin of opercular face of manus

usually rounded with tubercles diminishing laterally or channels becoming shallower. Some species

with patch of rugose striae on ventrolateral surface

of manus. Scattered setae in clusters over most

surfaces, tufts of strong setae distally on both dactylus and fixed finger or propodus. Tips of dactylus

and fixed finger dark, corneous, sometimes toothed

at abutting edges. Most species with row or rows

of corneous teeth or tubercles on inner face of

dactylus just under row of tubercles at dorsomesial

margin.

P2 with flattened or concave opercular surface

on distal 3 segments; these surfaces tuberculate,

other surfaces smooth. Mesial surfaces of distal 6

segments lightly concave or molded, fitting

smoothly against lateral surface of P1# Merus of

P2 flattened laterally but distal part expanded on

dorsolateral corner. (Merus and part of carpus of

P3 fitting against concavity behind this distal expansion of P2 merus). Flexure of carpus similar

to Pt but usually not as sharp; sometimes with

raised crest at flexure. Lobation always distinct

on sharp expanded dorsolateral edge of propodus;

in some species outer margins of carpus and dactylus also lobate. Clusters of setae along most

angular margins of opercular surfaces. Dactylus

terminating in curved dark corneous tip; longitudinal row of forward-projecting corneous denticles along ventral margin.

P3 without distinct opercular surface (except as

described for C. macrothrix), most surfaces smooth,

dorsolateral edge with tubercles, teeth, setae; scattered tufts of setae on ventral and distal parts of

most segments. Mesial surfaces of basis, ischium,

merus, and proximal part of carpus flattened or

slightly concave to lie smoothly against convex lateral surfaces of P2. Some species with distinct lobes

on dorsolateral edge of propodus. Dactylus terminating in curved dark corneous tip; longitudinal

row of corneous denticles on ventromesial margin.

P4 subchelate; pad of corneous granules cover-
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

ing most of distolateral surface of propodus. Dactylus often with longitudinal row of corneous

granules. Most other surfaces smooth. Outer

curved edge of carpus with fringe of long setae.

Pr> chelate; pad of corneous granules covering

anterolateral surface of propodus. Usually one or

more rows of corneous granules on dactylus and

fixed finger; tips spooned, usually with corneous

teeth on abutting distal margins.

Margins of most coxal segments, particularly

those of P4 with fringes of setae, often long and

plumose.

Fifth coxal segment on males of some species

rounded as in females, but most species with some

modification ranging from expanded prolongation

to shallow concavity on coxa.

Abdomen ellipsoidal or spherical, not coiled in

typical pagurid manner, but often with gentle flexure bringing tail fan to ventral position. First abdominal tergite small, usually calcified, located

close to cardiac region at junction of thorax and

abdomen. Remnants of other abdominal terga on

some species, appearing as hardened transverse

strips, partly calcified in some species, particularly

on large individuals. Females with 4 biramous

pleopods on one side of abdomen, hardening of

terga more apparent at insertion of pleopods. Pleopods lacking entirely on males.

Sixth abdominal tergite strongly calcified, symmetrical, hexagonal; transverse furrow and lateral

notches dividing plate into anterior and posterior

sections; rounded transverse carina and blunt lateral projections immediately anterior to furrow and

notches respectively.

Uropods equal; exopod larger than endopod,

both with pads of corneous granules distally.

Telson symmetrical; usually with slight swelling

medially.

REMARKS.—Of the nine known species of Cancellus, three are found in the West Indian region:

Cancclhts ornatus Benedict, C. spongicola Benedict, and C. viridis, new species. The only other

region with more than one species is the "east Indies" with C. invcstigatoris Alcock, definitely described from the Indian Ocean, and C. canaliculatus (Herbst) of questionable location. The other

species are C. parfaiti A. Milne Edwards and Bouvier from the eastern Atlantic and western coasts

of Africa, C. tanneri Faxon from the eastern Pacific, C. macrothrix Stebbing from South African

coasts, and the Australian species, C. typus H.

Milne Edwards (see Table 1).

An outstanding feature of this genus is the formation of an operculum by the distal segments of

the chelipeds and anterior ambulatory legs. Typically, the distal parts of only the first pair of walking legs, along with the chelipeds, take part in the

formation; the South African species, C. macrothrix, however, also uses the second pair. Barnard

(1950) has pointed out that this is anomalous, and

even questions whether that species should be considered a Cancellns. Since no specimens of C.

macrothrix were available for examination, the

species is included here for completeness, and its

taxonomic position is left undisturbed.

Another obvious characteristic of the genus is the

apparent symmetry of the abdomen, including the

telson and uropods. The abdomen is spherical or

ellipsoid and the male lacks pleopods. The presence of four biramous pleopods on one side or the

other of the female abdomen demonstrates the superficiality of the symmetry. Alcock (1905) stated

that Paguropsis was the only pagurid genus having

unpaired pleopods which may occur on either the

left or right side of the abdomen of the female.

All previous reports of Cancellus indicated that the

pleopods were usually on the left side, illustrating

the relation to the asymmetrical, more typical hermit crabs which inhabit gastropod shells. However, in the only species of which a number of individuals have been collected, C. spongicola, ten

of fourteen females had their pleopods on the

right side. Two C. ornatus, of eight females reported, have been noted to bear them on the right.

One of the two females of C. typus examined had

pleopods on the right side. Unfortunately there

have not been enough specimens collected to obtain ratios for any species but C. spongicola, or to

allow a generalization about the genus as a whole.

It is likely, though, that some, if not all, of the

species of Cancellus are losing or have lost the

pagurid tendency for the females to bear pleopods

on the left side, since "left-sided" animals living in

a cylindrical hole apparently have no advantage

over crabs bearing them on the right.

The question arises whether Cancellus, rather

than advancing beyond the pagurid nature to a

superficial symmetry, has instead not yet reached

the true asymmetry displayed by the more typical

pagurids. If this is the case it would be difficult to
NUMBER 150

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10 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

account for the fact that the animals never have

pleopods on both sides, and that some species have

them only on the left side—a pagurid character.

It is difficult to understand why pleopods should

be borne on one side if the animal has always lived

in a cylindrical cavity.

The only family of truly symmetrical hermit

crabs is the Pylochelidae. A. Milne Edwards and

Bouvier (1891) suggested that Pylocheles is a

"macruran," closely related to the thalassinids,

which has acquired pagurid characteristics in

adapting to life in hollowed-out stones, bamboo,

or other cylindrical cavities, whereas Cancellus is

probably a true hermit crab which has abandoned

gastropod shells to assume a mode of life, and

consequently an external form, similar to that of

Pylocheles. Boas (1926), in his study of symmetrical pagurids, maintained that the pylochelids were

indeed pagurids, although in a more primitive

position than the more typical hermit crabs. He

agreed, however, that the symmetry of Cancellus

was secondarily derived, and their similarity to

Pylocheles was a result of their adaptation to life

in similar cavities. In the dwelling, Cancellus can

be distinguished easily from the Pylochelidae since

the opercular surface is formed by a pair of ambulatory legs as well as the chelipeds, rather than by

the flattened chelipeds alone as in the Pylochelidae.

The abdomen of the pylochelids differs from that

of Cancellus in that all the pleopods are paired,

and the dorsal surface of the abdomen bears distinct, calcined terga; the whole animal looks very

much like a small thalassinid.

Both the opercular formation and the body

symmetry of Cancellus are related to the unusual

habit of living in cylindrical cavities. They have

been reported in pieces of calcareous rock, granular

stones, siliceous sponges, calcareous algae, and

dead coral. Only the anomalous South African

species, C. macrothrix, has been collected inhabiting a gastropod shell.

Balss (1956) remarked that it was not known

in what manner the tubes which Cancellus inhabits were formed. He speculated that the hole

was probably made by a worm (since, he said, the

crab could not bore it), possibly like a sipunculid

of the genus Aspidosiphon which lives in "snail

houses" that have been secondarily overgrown by

corals. Some specimens have been found in pieces

of coal which indicate they might not necessarily

be dependent on other animals to provide a tube

that is secondarily overgrown.

Balss repeated Boas' (1926) assumption that

Cancellus, like Pylocheles, must abandon its permanent dwelling for feeding purposes. Two young

females kept alive in our laboratory for eleven

months after capture were never seen out of their

stone dwellings. When walking from one side of a

four-inch finger bowl to the other in response to

the presence of food, they dragged the stone with

them. Presumably they came out of the dwelling

to moult since the moults were found outside the

stones. Although the stones used by these specimens were heavier in relation to body weight than

the mollusc shells used by typical pagurids, they

did not appear too heavy or bulky for the animals

to carry. Some specimens, however, have been taken

in stones, pieces of coral, and calcareous algae

which were so large and heavy that they could not

possibly have been carried with ease if the hermit

crab managed to move them at all. Therefore, it

appears that the animals drag their dwellings

about if possible or practical; it is not definitely

known whether they frequently leave an immovable dwelling to obtain food, since this activity has

not been observed. The abdomen of Cancellus is

almost as soft and vulnerable as that of typical

pagurids, and it would be in greater danger outside the dwelling than would Pylocheles with its

more protected "macruran-like" abdomen.

With regard to Pope's (1953) proposal that the

rasps on the posterior ambulatory legs and uropods

could be used as digging organs, it should be

pointed out that all of the gastropod-shell inhabiting pagurids possess these "anti-skid" surfaces

(Alcock, 1905) that are used to hold the animal

inside its dwelling (Bohn, 1902; Russell, 1962).

There is no evidence that these horny surfaces on

Cancellus are used for active digging. It seems

more likely that the pads, pressed against the inside of the tube, continually wear away material,

perhaps allowing the crab to enlarge the cavity

to keep pace with growth. All sponges and some

stones which had served as dwellings for animals

examined by this author were friable. One large

Cancellus was taken in a piece of siliceous sponge;

the burrow demonstrated the same curving away

from the surface as described by Pope (1953), and

there were many small shallow cavities that could

have served as starting niches for smaller crabs.
NUMBER 150 11

Since the holes in the more durable rocks were

much like those formed by animals known to drill,

such as the boring clams, it is probable that the

crab inhabited them secondarily.

Specimens of Cancellus parjaiti, the west African

species, often live in clumps of melobesiid algae

(Forest, 1959, 1961, 1966). Forest remarked that

melobesiids taken at littoral stations other than

where Cancellus had been collected often had a

characteristic cylindrical cavity which he said

showed that they had previously been occupied.

In all species except C. macrothrix, the sixth

abdominal tergite is symmetrical and strongly

calcined. This plate, sometimes together with the

telson and uropods, may be used to effectively block

the posterior opening of the hole, as in the genus

Xylopagurus (Alcock, 1905). Although many of the

dwelling cavities were open only at one end, the

others showed clearly the advantages a crab would

derive from having both ends protected.

In some species (C. spongicola, C. parjaiti, and

C. typus) the ventrolateral surface of the manus of

the cheliped has a distinct patch of regular striae

resembling part of the stridulatory mechanism

(pars stridens) in many decapods. That function is

suggested for this structure, but since stridulation

has not been observed in members of this genus,

a positive statement cannot be made. In some species (C. ornatus and C. tanneri) this area on the

manus is irregularly ridged or tuberculate; in C.

viridis, new species, it is practically smooth.

Information about the life history of Cancellus

consists of brief descriptions of young associated

with adult females of C. typus and C. macrothrix

(Hale, 1941; Barnard, 1950). Both cases indicate

direct development, with the young clinging to

the abdominal appendages until at least the glaucothoe or juvenile stage. Provenzano (personal

communication) reports a zoeal stage present in C.

spongicola.

Generalizations about relationships within the

genus are not yet justified due to the small amount

of material collected. Based on morphological similarities of the available specimens, however, there

appear to be two groups of species (or species

complexes). Species in the first group (C. typus,

C. parfaiti and C. investigatoris) are characterized

by a divided frontal rim on the shield, a flattened

opercular surface on the chelipeds, a patch of regular striae on the ventrolateral surface of the chelipeds, and an unarmed frontal margin on the sixth

abdominal tergite. Those in the second group (C.

ornatus, C. tanneri, and C. viridis, new species)

have a continuous inflated frontal rim, the opercular surface of the chelipeds concave, no patch of regular striae on the ventrolateral surface of the

chelipeds, and heavy spines on the sixth abdominal

tergite. This division is not absolute: C. typus,

while it is associated with the first group, has the

fifth coxal segments on the male concave, as do

the species in the second group. C. canaliculatus

has the divided frontal rim, only slightly concave

opercular surface of the chelipeds, but no patch of

striae on the chelipeds; the morphology of the sixth

abdominal tergite is not known, but this species

also appears to be intermediate in the nature of its

characters. C. spongicola seems to be allied more

closely with the first group than the second, but

some of its characters (the frontal rim of the shield

and armature of the sixth abdominal tergite, for

example) are intermediate between those of each

group. C. macrothrix may show characters of a

more primitive Cancellus, as explained in the

species account.

Key to Species of Cancellus

(This key should not be used independently of the full descriptions appearing in the text)

1. Telson and uropods symmetrical; abdomen with gentle anteroventral flexure, not

spirally coiled; operculum formed by chelipeds and Ps; carpus of cheliped and

P2 strongly projected 2

Telson and uropods not symmetrical; abdomen spirally coiled; operculum formed by

chelipeds, P2 and P3; carpus of cheliped and P2 not strongly projected; South African

species 9. C. macrothrix Stebbing

2(1). Frontal rim of shield continuous between blunt lateral teeth; anterior margin of sixth

abdominal tergite with many strong or truncate spines; opercular surface of cheliped

concave or with longitudinal groove 3
12 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Frontal rim of shield divided into at least three parts by depression behind eyes; anterior

margin of sixth abdominal tergite nearly smooth; opercular surface of cheliped flat

or slightly concave 5

3 (2). Ocular scale with more than one terminal tooth or spine; fifth coxal segments of male

flattened; overall color of live or recently preserved specimens green; western Atlantic

species 3. C. viridis, new species

Ocular scale with one triangular tooth; fifth coxal segments of male concave and expanded; overall color than green 4

4 (3). Lateral face of merus and propodus of P2 noticeably longer than twice the width of

these segments; calcified part of cardiac region subrectangular, broader than long,

posterior margin straight; overall color cream with purple, dark red or brown; checker

board pattern on opercular surface, western Atlantic species .2 . C. ornatus Benedict

Length of lateral face of merus and propodus of P2 barely twice or less than twice

the width; calcified part of cardiac region longer than broad, posterior margin a

rounded point; color (according to Faxon) white with red spots, spots tending to

coalesce in bands on ocular peduncles and legs; eastern Pacific species

4. C. tanneri Faxon

5(2). Manus of cheliped with distinct patch of parallel striae on ventrolateral surface 6

Manus of cheliped with forward projecting tubercles or ridges on ventrolateral surface,

but no distinct patch of striae; dorsal projection of carpus of cheliped divided into

two lobes; dorsolateral margin of manus of cheliped with toothed transverse projections, becoming lobular distally; an indentation in lateral surface below distalmost

projections 7. C. canaliculatus (Herbst)

6 (5). Ocular scale usually with more than one terminal tooth or spine; narrow raised rim

parallel to and just behind angular frontal margin, divided into four parts by depressions at apex of rostrum and behind eyes 7

Ocular scale usually with one terminal tooth or spine; frontal rim of shield inflated,

divided into three parts by depressions behind eyes 8

7 (6). Cornea inflated; ocular peduncle two-thirds/ to three-fourths shield length, smooth;

basal segment of antennular peduncle with four broad teeth on anterolateral margin;

two spines or heavy teeth on raised dorsal edge of antennal acicle; anterior margin

of sixth abdominal tergite smooth; overall color orange, pink and cream; eastern

Atlantic species 5. C. parfaiti A. Milne Edwards and Bouvier.

Cornea not as wide as distal part of ocular peduncle; ocular peduncle about one-half

length of shield with spines on mesial proximal surface; three or four spines on

raised edge of antennal acicle; one or more low, tooth-like protuberances on anterior

margin of sixth abdominal tergite; western Pacific species 8. C. investigatoris Alcock

8 (6). Anterior surface of shield with transverse sculpturing behind straight transverse depression; cheliped with deep transverse channels on dorsolateral margin; eyes slightly

wider than eyestalks; reduced or truncate spines on anterior margin of sixth abdominal tergite; setae on appendages and body, but not extremely hirsute; fifth coxal

segments of male round; overall color orange and cream; western Atlantic species

l.C. tpongicola Benedict

Sculpturing on anterior part of shield in form of round granules or tubercles, but no

deep transverse channels; eyes slightly narrower than eyestalks; anterior margin of

sixth abdominal tergite smooth; appendages and body hirsute; fifth coxal segments of

male expanded and concave; color of preserved material (according to Zietz) reddish,

limbs marked with large dark red spots, some forming bands on the legs; Australian

species 6. C. typus Milne Edwards

1. Cancellus spangicola Benedict, 1901 MATERIAL.—1 $, 6.5 mm, holotype; Albatross sta.

2354, Arrowsmith Bank; 2O°59'3O"N, 86°23'45"W;

FIGURES 2-4

238 m; in a siliceous sponge; 22 January 1885;

Cancellus spongicota Benedict, 1901:773, figs. 3, 4.—Alcock, USNM 9549.— 1 ovigerous 9 (yielded larvae), 8.6

1905:167 [list].—Cordan, 1956:306 [list]._Russell, 1962: mm; G-232, south of Bimini; 25°36'-39/N, 79°20.5'-

19—Hazlett, 1969:219-220. 21'W; 439-421 m; no dwelling taken; 29-30 Janu-
NUMBER 150

FIGURE 2.—Cancellus spongicola Benedict. Male, si. 7.1 mm, G-387: a, carapace (setae omitted

on right side) ; b, coxal segments. Male, si. 9.7 mm, G-798: c, antennular peduncle, lateral

view. Female, si. 5.2 mm, G-591: d, sixth abdominal tergite and telson; e, left uropod, dorsal
14 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

ary 1964; W otter trawl; UMML 4137.—3^, 7.1

mm, 4.4 mm, 3.8 mm; 1 $, 5.0 mm; G-387, north of

Grand Bahama Island; 27°17'N, 79°15'W; 412 m;

all in pieces of siliceous sponge; 19 September

1964, 5' screen dredge; USNM 128741 (illustrated),

128742, 128743, 128751.—1 5, 4.7 mm; G-633, north

of Bimini; 25°59'-26°01'N, 79°19'-18'W; 439-458

m; in a siliceous sponge; 30 June 1965; 10' otter

trawl; USNM 128746.—1 <$, 9.7 mm; G-798, north

of Bimini; 25°56'-26°00'N, 79°22'-17.5'W; 402.3

m; in a piece of calcareous rock; 12 September

1966; otter trawl; RMNH Reg. No. Crust.

D 26550.—1 ovigerous 2 , 9.3 mm; 1 9, 3.7 mm;

G-893, Arrowsmith Bank; 21°10'N, SG^l'W, 242-

320 m; 1 9 in a piece of calcareous rock; 10 September 1967; 10' otter trawl; UMML 4133.—1 $ ,

3.3 mm; G-897, Arrowsmith Bank; 20°59'N,

86°24'W, 210-293 m; no dwelling taken; 10 September 1967; 10' otter trawl; RMNH Reg. No.

Crust. D. 26551.—2$, 8.2 mm, 4.7 mm; 1 $, 3.9

mm; G-899, Arrowsmith Bank; 20°57'N, 86°34rW;

40-165 m; 1 $ without dwelling, 1 $ in a siliceous sponge, 9" in a piece of coral rock; 10

September 1967; 10' otter trawl; USNM

128747.—1 S, 3.9 mm; G-947, Arrowsmit h

Bank; 21°13'N, 86°25'W; 247-284 m; in a piece

of rock; 27 January 1968; triangular dredge;

UMML 4134.—1 $ , 3.7 mm; 1 9, 5.2 mm; G-951,

Arrowsmith Bank; 21°06'N, 86028^; 192-298 m;

S in sponge, 9 without dwelling; 28 January

1968; 10' otter trawl; USNM 128748.—2 $ , 3.5 mm,

2.3 mm; 2 9 , 4.0 mm, 3.6 mm; G-952, Arrowsmith

Bank; 21°02' N, 86°26'W, 586-92 m; no dwellings

taken; 28 January 1968; 10' otter trawl; UMML

4136.—1 s , 3.1 mm; 1 ovigerous 9 , 3.1 mm; P-592,

Arrowsmith Bank; 21°00'N, 86°23'W; 174-348 m;

9 in sponge; 15 March 1968; \(/ otter trawl;

UMML 4135.—19, 3.1 mm; P-594, Arrowsmith

Bank; 20°00.5'N, 86°23'W; 298-329 m; in sponge;

15 March 1968; 10' otter trawl; USNM 128744.—1

ovigerous 9, 5.4 mm; P-595, Arrowsmith Bank;

21°08.5'N, 86°27'\V; 33-586 m; in sponge; 15

March 1968; 10' otter trawl; USNM 128745.—1 9 ,

4.7 mm; P-596, Arrowsmith Bank; 21°04'N,

86°22'W; 46-293 m; no dwelling taken; 15 March

1968; box dredge; RMNH Reg. No. Crust. D

26552.—1 9, 6.2 mm; Oregon sta. 4834, off Serrana

Bank; 14°14.2'N, 80°28.5'W; 275-293 m; in a piece

of siliceous sponge; 12 May 1964; 6' tumbler

dredge; USNM 128749.—2^, 10.2 mm, 7.3 mm;

1 9 , 6.2 mm; Oregon sta. 4941, Arrowsmith Bank;

20°59'N, 86°29'W; 201 m; 2 ? in calcareous rock;

12 June 1964; 6' tumbler dredge; USNM 128750.

DESCRIPTION.—Cephalothoracic shield shorter

than maximum width (sl./sw.=0.80-0.95), slightly

convex anteroposteriorly. Anterior margin inflated,

dorsally flattened, merging with rounded anterolateral margin; postorbital indentations angular. Triangular rostrum with tiny denticle at apex, barely

exceeding blunt lateral projections. Depression in

surface of frontal margin on each side of rostrum

behind ocular scales. Subdiamond or triangularshaped depression behind rostrum connected to

triangular depressions behind antennal acicles by

narrow groove; margin of groove straight anteriorly,

but curved posteriorly, bordering 2 raised sculptured semicircular areas; scattered short setae in

depressions. Gastric pits elongate slits near posterolateral margin of shield. Sculpturing on anterolateral margin limited to longitudinal furrow or

irregular row of pits with setae. Indentations in

posterolateral margin with postorbital indentations

giving shield slightly three-lobed appearance, especially in larger specimens.

Cardiac region broader than long; several (usually 4 to 6) groups of setae along anterior margin.

Ocular scales with mesial half projecting anteriorly to triangle, terminating in sharp point

or spinule; setae on anterior margin and dorsal

surface.

Ocular peduncle about three-fourths length of

shield, slightly arcuate and narrower in middle;

smooth with scattered setae along inner dorsal

margin. Cornea slightly inflated, rounded, faceted,

with angular emargination in dorsal part of basal

line. Antennular peduncle reaching almost to distal part of cornea; basal segment with 2, sometimes

3, teeth anteroventrally; flagellum composed of as

few as 13 segments in smallest specimens and as

many as 24 in large ones.

Antennal flagellum approximately same length

as ocular peduncle. Fifth article of antennal peduncle reaching about one-half to two-thirds length

of ocular peduncle. Acicle reaching one-third to

one-half length of ocular peduncle with 3 anterior

or anterolateral spines, one on inner margin posterior to these; occasionally an additional spine

on inner or outer margin.

Posterior dorsal margin of carpus of cheliped in

3 or 4 tuberculate lobes. Opercular face of manus
NUMBER 150 15

a

FIGURE 3. Cancellus spongicola Benedict, male, si. 7.1 mm, G-387: a, left cheliped; b, left

pereiopod 2; c, left pereiopod 3. (All lateral views.)
16 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

flat; evenly tuberculate; rounded protuberance

mesially on distal margin of opercular surface;

angle between opercular and inner faces sharp, 6

deep fissures dividing margin into 7 tuberculate

lobes; 7 or more deep transverse rounded channels

on dorsolateral margin extending down onto lateral face of manus, often with shorter shallower

channels between deep ones; distinct patch of 8

or more closely spaced dorsoventral striae on

ventrolateral surface; 2 or 3 ridges with several

anteriorly projecting teeth and setae on ventral

surface. Inner surface of dactylus with 2 rows of

corneous projections, 3 to 6 in upper row, 2 to 5

in row beneath; several tubercles with similar

corneous projections (resembling the corneous

granules on rasps of P4, P5, and uropods) on

dorsal inner margin above rows.

Opercular face of P2 flat to very slightly concave,

covered with low tubercles. Inner dorsal margin of

carpus divided into small groups of tubercles by six

or seven shallow fissures; outer margin with 5

toothed lobes separated by deeper fissures. Inner

margin of propodus divided into 7 or 8 groups of

tubercles, usually paired; fissures between groups

extending about one-third distance across dorsal

surface; outer margin separated into five toothed

lobes, occasionally subdivided to form 6 or 7 lobes,

usually no teeth on sides of lobes in lateral view.

Inner dorsal margin of dactylus with 6 or 7 small

groups of tubercles of diminishing height; outer

ridge with three or four tuberculate lobes proximally, diminishing in size to small separate teeth

distally; three horny denticles on ventral margin

of dactylus, one denticle immediately behind

corneous tip.

Merus and carpus of P;} smooth proximally with

low, anteriorly projecting teeth more distinct toward dorsal distal ends of these segments. Dorsal

ridge of propodus with 5 toothed projections,

larger distally. Dactylus with 7 or more dorsal

teeth diminishing in height distally; ventral margin with 3 corneous denticles and one adjacent

to dark tip.

Propodus of P4 with round pad of corneous

granules covering two-thirds of outer face. Dactylus

extending one-half to two-thirds distance to end of

pad, with 1 to 3 corneous denticles near distal end.

Carpus with small tooth near articulation with

propodus.

Dactylus of P5 more than one-third length of

propodus. Elongate pad of granules on propodus

extending onto dactylus, diminishing to single

row of granules.

Fifth coxal segment rounded on males and females. Fourth coxal segment with many plumose

setae on all margins.

Females with 4 biramous pleopods on one side

of abdomen. On females, "remnants" of 4 abdominal terga discernible at insertion of pleopods,

particularly on large specimens. Hardened areas

(but not calcified) only on abdomen of largest

males. Small individuals of both sexes with spherical abdomens covered with short setae.

Length of sixth abdominal tergite approximately

two-thirds maximum width. Anterior to rounded

lateral projections on forward part of plate, a

heavy lateral spine on each side. On anterolateral

margin, rounded ridge with 4 or 5 groups of spines

and setae, often reduced, irregular and truncate

medially. On anterior lobe in front of carina, a

deep curved depression; lateral to this on each

side, a protuberance armed with a spine, setae, or

both. Other spines symmetrically arranged over

surface. Posterior lobe divided by medial longitudinal depression; raised, rounded areas on either

side with several spines and setae. Posterolateral

margin with 3 or 4 blunt triangular teeth on each

side; posterior margin with 3 or 4 similar teeth on

each side (12 to 14 teeth total).

Protopod with 2 rounded protuberances posteriorly; on some specimens, a group of setae between protuberances; occasionally a third protuberance beneath others. Anterior to these on dorsal

surface, a single rounded protuberance, spine, or

small group of setae.

Telson rounded, slightly wider than long. A

depression around medial swelling. Rounded protuberances with setae and spines scattered over

surface.

COLOR.—The overall color pattern of preserved

material is light orange with pale straw or white

mottling. All anterior appendages, including ocular

peduncles, antennal acicles and peduncles, and

pereiopods, have orange mottling; the color is

generally more intense on exposed and dorsal

surfaces. A white knob on the dorsal distal margin

of the manus is distinct against the orange surface

of the cheliped. There are suggestions of mottled

bands on the meri of the chelipeds and ambulatory

legs. There are concentrations of color in the post-
NUMBER 150 17

a

FIGURE 4.—Cancellus spongicola Benedict, male, si. 7.1 mm, G-387: a, left pereiopod 2, mesial

view; b, left pereiopod 3, mesial view; c, left pereiopod 4, lateral view; d, left pereiopod 5,

lateral view.
18 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

orbital indentations of the frontal margin of the

shield, in some of the depressions, and on the

raised anterior semicircular areas in the gastric

region. The branchial regions are also pigmented,

particularly in the anteromesial areas. The tail fan

is very pale in comparison to the rest of the animal.

The corneous tips on the fingers of the chelipeds

and ambulatory legs are dark brown to black.

TYPE.—USNM 9549. (See "Material.")

TYPE-LOCALITY.—Arrowsmith Bank, off the

Yucatan Peninsula, Caribbean Sea.

DISTRIBUTION.—Bimini; north of Grand Bahama

Island; near Serrana Bank (off Honduras); Arrowsmith Bank. Most of the animals in the collections

made by the Gerda and Pillsbury came from Arrowsmith Bank and Bimini. In depths of 33 m to

586 m. (See summary of species records, Table 1.)

REMARKS.—Of 18 specimens with their dwellings

preserved, 12 were in siliceous sponges, 5 were in

pieces of calcareous rock, and one inhabited a piece

of dead coral. While most of the sponges were

friable enough to have been rasped out by the

crab, the holes in the more durable rock were probably drilled by another animal, very possibly one

of the boring clams (Donald R. Moore, personal

communication).

DISCUSSION.—Cancellus spongicola can be separated easily from the other western Atlantic species of Cancellus by the flat opercular surface of

the chelipeds (as opposed to the distinctly concave

or longitudinally grooved manus of the other

species), the deep grooves on the dorsal external

surface of the manus, and the patch of striae near

the ventral margin. Also, the triangular rostrum

and dorsally flattened frontal swellings of the

carapace, with its postorbital indentations, are

distinctive. The lobes on P2 are usually rectangular

and toothed only on the upper surface while in

other species they are expanded, thinner, and tuberculate on all margins. The dorsal margin of the

propodus of P:, usually has five distinct groups of

teeth, while in other species the teeth are arranged

irregularly. The orange markings on live or recently

preserved material are characteristic.

Cancellus spongicola appears to be most closely

related to C. parfaiti A. Milne Edwards and Bouvier, a West African species, but the differences

between the two are many and distinct: C. parfaiti

has a raised ridge (in four parts) on the rim along

the frontal margin and a granulated area on the

anterior part of the shield which are not present in

C. spongicola. The chelipeds of C. parfaiti, like

C. spongicola, have the patch of striae on the ventral

outer surface of the manus, but lack entirely the

deep transverse channels on the dorsal outer margin. The opercular surface of the manus of C.

parfaiti is more concave. The dactylus of P2 of C.

parfaiti is only barely toothed, rather than lobed

as in C. spongicola. The anterior margin of the

sixth abdominal segment is smooth in C. parfaiti,

and the telson is longer with respect to width and

more rectangular. The ocular scales of C. parfaiti

are often armed with two or three tiny denticles,

whereas the scales of C. spongicola always have one

strong triangular tooth.

Of 14 female specimens of C. spongicola examined, 10 had pleopods on the right side and 4 had

them on the left.

In large animals, the eyes are usually slightly

wider than the eyestalks; smaller specimens have

eyes noticeably wider, and the eyestalks are broader

relative to their length (and shorter relative to

shield length). The indentations in the upper surface of the frontal margin are less distinct on small

specimens, and the frontal margin may be more

rimlike (as opposed to the broad dorsally flattened

frontal swelling in larger specimens). In the largest

specimens the shield width increases relative to the

shield length.

The black corneous area on the ends of the

dactylus and propodus of the chelipeds may vary

in length, and appears to wear down with use,

since that area on an animal which had just

moulted was obviously longer than that on the

moult.

Observations of the behavior of six of the specimens from Arrowsmith Bank were recorded by

Hazlett (1969). He concluded that patterns of

"stone movement" were clearly diogenid rather

than pagurid, and were even closer to patterns of

other hermit crabs in the subfamily Diogeninae

than to those in the subfamily Dardaninae.

2. Cancellus ornatus Benedict, 1901

FIGURES 5-8

Cancellus ornatus Benedict, 1901:772, figs. 1, 2.—Alcock,

1905:167 |list]._Gordan, 1956:306 [list]._Russell, 1962:

19.

Cancellus calypso Forest and St. Laurent, 1967:96-98, figs.

54-59.
NUMBER 150

19

FIGURE 5.—Cancellus ornatus Benedict. Male, si. 9.4 mm, G-503: a, left antennular peduncle,

lateral view; c, carapace; d, coxal segments. Nfale, si. 6.2 mm. Silver Bay Sta. 3497: b, left

antennular peduncle, lateral view; e, fifth coxal segments.
20 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

MATERIAL.—1 $, 5.5 mm, holotype; Albatross

sta. 2405, NE Gulf of Mexico; 28°45'N, 85°02'W;

55 m; no dwelling taken; 15 March 1885; USNM

9784.—1 $ , 9.4 mm; G-503, south of Grand Bahama Island; 26°31-29'N, 78°51-45'W; 366 m; in a

piece of siliceous sponge; 14 February 1965; 10'

otter trawl; USNM 128737.-19, 2.7 mm; P-707,

northwest of Trinidad; 11°21-23'N, 62°21'W; 76

m; in a piece of calcareous rock; 19 July 1968;

10' otter trawl; UMML 4131.—1 9 , 4.8 mm; P-708,

northwest of Trinidad; 11°24-26'N, 62°40.5'W;

69-73 m; in a piece of calcareous rock; 19 July

1968; 10' otter trawl; UMML 4132.—1 9, 7.9 mm;

P-734, west of La Tortuga, southeast Caribbean;

ll°01-02'N, 65°34-36'W; 68 m; no dwelling taken;

22 July 1968; 10' otter trawl; RMNH Reg. No.

Crust. D 26549.—1 9, 6.0 mm; P-854, off Grenada,

Windward Islands; 12°02'N, 61°36'W; 66-84 m; no

dwelling taken; 3 July 1969; 10' otter trawl; USNM

128738.—1 9, 8.2 mm; Oregon sta. 6715, near

Sombrero, Leeward Islands; 18°36'N, 63°27'W;

201-238 m; no dwelling taken; 30 May 1967; 6'

tumbler dredge; USNM 128739.—1 $, 6.2 mm;

Silver Bay sta. 3497, southwest of Great Inagua

Island; 20°53'N, 73°44'W; 265 m; in a piece of

siliceous sponge; 4 November 1961; 40' two seam

trawl; USNM 128740.

DESCRIPTION.—Cephalothoracic shield shorter

than maximum width (si./sw.=0.80-0.95); anterior

margin between antennal peduncles with rounded

postorbital indentations, bordered by continuous

flattened "collar-like" rim, slightly broader laterally.

Rostrum broad, a rounded triangle with slightly

concave sides, barely exceeding blunt lateral projections. Anterior margin of rostrum finely serrate.

Occasionally a tiny spinule or spinules on anterior

margin of rim at lateral terminations. Crescentic

transverse depression behind frontal rim, parallel to rim on its anterior margin, wider behind

ocular peduncles and diamond shaped behind rostrum; scattered setae in depressions. Small swelling

in depression immediately behind rostal apex;

short, mediolongitudinal groove posterior to swelling separating 2 semicircular transversely sculptured areas. Similar irregular transverse sculpturing

on anterolateral surface of shield, extending mesially behind frontal rim to a point posterior to

ocular peduncles. Central gastric region smooth

with scattered pits at bases of setae. Gastric pits

round to oval. Setae on anterior and lateral margins of shield. Indentations on posterolateral margins and postorbital indentations giving shield

three-lobed appearance.

Calcined part of cardiac region broader than

long; several groups of fine setae across anterior

margin; posterior margin straight, posterolateral

corners rounded.

Mesial half of ocular scale projected anteriorly

to a triangle with setae, armed distally with one

spinule. Ocular peduncle two-thirds to threefourths length of shield, broader proximally and

distally, more slender at a point even with antennal

acicle. Inner and dorsal surfaces of ocular peduncle

slightly flattened forming a rounded ridge^at their

boundary, with irregular row of broad low tubercles

and associated setae; proximal tubercles with one or

two spinules. Cornea slightly inflated; basal margin

with triangular emargination on dorsal surface.

Antennular peduncle reaching cornea when extended. Basal segment usually with 3 or 4 welldeveloped spines anteroventrally on large animals.

Antennular flagellum approximately equal to or

slightly shorter than ocular peduncles.

Antennal flagellum longer than ocular peduncle,

reaching about middle of ocular peduncle. Acicle

reaching about one-third length of ocular peduncle; armed with 3 anterior or anterolateral teeth,

one on inner margin behind these; occasionally

additional tooth or teeth on inner or outer margin.

Sometimes additional tooth under outer tooth on

basal segment of peduncle.

Opercular face of cheliped irregularly tuberculate with longitudinal concavity; tubercles often

denticulate or spinelike. Dorsolateral margin of

manus rounded with indistinct short transverse

channels; slightly larger widely spaced tubercles in

indistinct longitudinal row lateral to concavity,

row more distinct in smaller specimens; inner margin divided into about 6 groups of tubercles with

setae, separated by fissures at bases between groups;

these usually subdivided, forming up to 9 toothed

lobes; on ventral margin of manus, several transverse ridges with forward-projecting spinules and

setae; lateral to these, other transverse ridges extending dorsally on lateral surface. Lateral and

mesial faces of manus smoothly reticulate with

short setae and fine sculpturing. Inner surface of

dactylus with 2 rows of corneous denticles, 4 to 6

denticles in dorsal row, 2 to 4 in row below; several tubercles in row on inner dorsal margin of
NUMBER 150 21

FIGURE 6.—Cancellus ornatus Benedict. Female, si. 6.0 mm, P-854: a, chelipeds and pereiopods

2 (shaded areas indicate color pattern) . Male, si. 9.4 mm, G-503: b, left cheliped, lateral view;

c, left pereiopod 3, mesial view; d, left pereiopod 2, mesial view.
22 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

dactylus armed with denticles. Posterior and lateral borders of opercular face of carpus with projecting ridge divided into about 4 toothed lobes

with setae.

Opercular face of P2 tuberculate, carpus and propodus slightly concave, dactylus flat. Inner dorsal

margin of carpus irregularly toothed, most teeth

armed with a tiny denticle; outer ridge divided

into 4 or 5 toothed lobes. Inner margin of propodus with 6 small groups of armed tubercles and

one toothed distal lobe; tubercles on face of propodus in irregular transverse rows—more distinct

toward inner margin; some tubercles armed with as

many as 7 or 8 denticles; outer margin in 5 distinct lobes with setae, occasionally one subdivided

into two shallow lobes; lobes foliaceous and expanded, their margins frequently touching; lateral

surface near bases of fissures between lobes with

several many-denticled protuberances; tiny denticle

on distal lower margin of propodus at insertion of

dactylus. Inner margin of dactylus with row of

about 10 armed tubercles of diminishing height

with interspersed tufts of heavy setae; 4 to 8 corneous denticles on ventral margin of dactylus with

one flattened against dark tip; outer margin in 5

to 10 sections, proximal 4 or 5 are tuberculate

lobes, remainder are armed tubercles diminishing

in size distally. Length of merus and propodus

noticeably greater than twice the width of these

segments, measured on lateral surface.

Dorsal surface of carpus of P3 broadening distally with several armed tubercles. Dorsal surface

of propodus rough with 8 or 9 prominent tubercles armed with forward-projecting spinules and

associated setae; denticle on distal lower margin of

propodus. Dactylus with dorsal row of about 5 to

10 armed teeth and tufts of setae; ventral margin

with a row of 5 to 7 corneous denticles, one adjacent to corneous tip. Length of merus and propodus usually noticeably greater than twice the

width of these segments.

Corneous pad on P4 oval, slightly longer than

wide. Dactylus slender, extending to about twothirds reach of pad, with row of 4 to 6 tiny denticles. One or two spines on distal end of carpus at

insertion of propodus.

Dactylus of P5 more than one-third length of

propodus. Corneous pad extending onto dactylus

as row of about 10 corneous granules.

Margins of fourth coxal segments with heavy

fringe of long fine setae.

Fifth coxal segments of male broadly depressed

in center with gonopore on rounded anterior margin, slightly mesial to center of segment. Tufts of

short strong setae on inner adjacent margins of

coxae.

Abdomen ellipsoidal, covered with many short

setae. Females with 4 biramous pleopods on one

side of abdomen; large females with hardened

transverse strips at base of and mesial to pleopods.

Sixth abdominal tergite broadly hexagonal; its

length two-thirds maximum width. Anterior lobe

larger than posterior. Blunt triangular lateral

projections at ends of rounded transverse carina

with a single strong spine, sometimes bifid, inserted anterior to them near lateral borders. Ridge

on each side of forward margin armed with 8 to 11

strong uneven spines. Shallow longitudinal depression in center of plate. Raised areas with spines

and setae scattered over anterior lobe. Raised area

on either side of posterior lobe with scattered

spines and setae. Posterolateral border with

toothed ridge. Medial ridge on rear margin with

2 groups of teeth, most posterior teeth armed with

tiny spinules.

Surface of protopod with 2 or 3 tufts of setae,

depressed to margins; backward projection with

2 to 4 blunt teeth or rounded protuberances;

single spine projecting posteriorly from underneath.

Telson broader than long, with many short setae

on posterior margin, several on surface and other

margins. Two anterolateral depressions on either

side in front of a raised central area. Surface uneven with scattered short setae.

COLOR.—The general color pattern in several recently preserved specimens is dark violet on a

cream-colored background with scattered red and

orange markings. There are large dark violet areas

on the carapace, particularly on the anterior sculptured areas. Orange and red markings are mainly

in depressions. There is a distinct red spot on each

side of the shield just anterior to the gastric pit,

and a broad pigmented spot on the side of the

thorax just below the lateral margins of the carapace. The anterolateral corners of the cardiac region also have a concentration of color.

The dorsal surface of the ocular peduncle is violet with small diffuse patches of red and with white

or cream-colored tubercles; the undersurface is
NUMBER 15« 23

FIGURE 7. Cancellus ornatus Benedict, male, si. 9.4 mm, G-503: a, left pereiopod 2; b, left

pereiopod 3; c, left pereiopod 5; d, left pereiopod 4. (All lateral views.)
24 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

white with orange patches. There is an indistinct

longitudinal line along the lateral surface.

The maxillipeds have a pigmented band around

most of the segments.

The antennules are pale orange or cream with

yellow flagella.

The ocular scales have distinct patches of color

on a cream-colored or white background. The antennal acicles have red markings; there is a pigmented band around the middle of the fifth article

of the antennal peduncle.

The chelipeds show dark violet patches on the

lateral opercular surfaces and on the inner raised

margins, with a large diffuse violet area on the inner

face of the manus.

The opercular surfaces of the chelipeds and first

ambulatory legs have somewhat rectangular areas

of pigmentation which give an impressive checkerboard effect when the legs are drawn together.

Most undersurfaces of legs and the coxal segments

are cream with scattered red markings. The ambulatory legs are generally cream with violet banding; the bands around the proximal part of each

propodus are continuous. There is a broad violet

band covering most of the dorsal and outer surfaces of each carpus. The meri have large purple

patches on the dorsal surfaces, narrowing ventrally.

There are red spots on some of the violet areas.

P4 is cream with a red-violet patch in the middle

of the upper surface of the carpus and merus.

Pr, is pearlescent with a few scattered red marks.

There are many small red spots on the abdomen.

Red patches are arranged symmetrically on the

sixth abdominal tergite and telson, frequently at

the bases of certain setae; there are four conspicuous ones medially on the forward part of the segment and one near each end of the transverse

carina; two spots appear on each side of the posterior lobe. There is a distinct patch of red in the

middle of the posterior border. Four tiny spots are

arranged in a curved transverse row across the front

part of the telson. The uropods are cream, slightly

pearlescent, with scattered light red patches.

One strikingly colored female specimen exhibited

the same general patterns described, but the pigment was brownish violet or brownish red instead

of violet. This animal had three distinct spots of

this color across each of the transverse hardened

elements on the abdomen mesial to the pleopods.

The general background color varied from cream

to light orange brown.

The violet color seems to fade very rapidly from

preserved animals; the red and orange markings

persist for a longer time.

TYPE.—USNM 9784.

TYPE-LOCALITY.—Northeast Gulf of Mexico.

DISTRIBUTION.—See "Material." The only other

animal collected was a small female (total length,

4.8 mm) taken near Abrolhos off the coast of Brazil by the Calypso, sta. 81, 18°06.5'S, 38°42'W, 37

m, 28 November 1961. There has never been more

than one specimen taken at a location. Other material is from depths of 55-366 m. Both male specimens came from deeper waters (366 m, 265 m)

than five of the females which were taken from

55-84 m. One female came from 201-238 m.

REMARKS.—Of the four specimens taken with

dwellings, two males were in pieces of siliceous

sponge, and two females were in pieces of calcareous rock. The sponges were friable and open

at one end only. The rocks were harder and open

at both ends.

DISCUSSION.—Two small specimens taken near

Trinidad since the description of Cancellus calypso

Forest and St. Laurent, 1967 (from the coast of

Brazil), show characteristics intermediate between

the tiny individual described as C. calypso and the

much larger type-specimen of C. ornatus as well

as other individuals positively identified as C ornatus. This indicates that C. calypso is probably

a juvenile of C. ornatus. Forest and St. Laurent

(1967) said that C. calypso was certainly very close

to C. ornatus. A. J. Provenzano had suggested that

it was a distinct species (in Litt.).

Forest and St. Laurent (1967) stated that the

Cancellus captured by the Calypso differed from

C. ornatus in the number of spines on the ridge

at the anterior margin of the sixth abdominal tergite. The specimen taken by the Calypso has nine

spines on the left and seven on the right. The type

specimen of C. ornatus has six on the left and eight

on the right. Benedict's original description (1901)

of the spination, ". . . . a group of four on one

side of the notch and six on the other . . .", is

slightly misleading since he counted the two lateral

spines of each group separately. The small female

specimens have nine to twelve on each side. The

larger specimens of C. ornatus (from Gerda, Oregon and Pillsbury stations) have eight to ten spines

on each side. Thus the number of spines is varia-
NUMBER 150 25

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26 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

ble over a range which includes the number of the

animal taken by the Calypso (see table 2). The

distinct row of larger tubercles on the cheliped of

the specimen collected from the Calypso is not apparent in most of the large specimens of C. ornatus. There are a few conspicuous tubercles

(occasionally in an irregular line) on the palms

of the animals from Trinidad, which suggests that

prominent tubercles become less distinct with increased size of the individual. One large C. ornatus (P-734) shows large "double" tubercles

arranged in a row on one palm and scattered irregularly on the other, indicating the variability

of this character even in the same individual.

The two male specimens of C. ornatus are

slightly different from the six females examined.

The most apparent difference is in the opercular

surface of the palm of P^ It is concave but smooth

in the males, while in the females there is a distinct longitudinal proove. The tubercles appear

more irregular in the females. The inner surface

of the palm, near the dorsal margin, is smoother

in the females, and the fissures are fairly regular

and consistent in number (five). These fissures in

the males are irregular and there are as many as

eight or nine, although five of them are often

deeper or more pronounced than the others. Also,

the spines just anterior to the transverse carina

on each side of the sixth abdominal tergite are

monofid in all the females examined (except one

side of one female, P-854). One of the males had

both of these bifid, and the other had one bifid.

There are differences between the two male

specimens also. Although they have both been

identified herein as C. ornatus, the specimen taken

by the Silver Bay near Inagua is less like the females than the male captured by the Gerda in the

Bahamas. Forest (personal communication) believes the differences are such that it is difficult to

consider these the same species. Since the range of

variation is not known due to the small amount

of material collected, these differences are simply

listed here rather than being taken as the basis for

the description of a new species. The telson of the

male from Inagua is slightly lobed and has spines

at the anterolateral margins, one on the left and a

bifid spine on the right. The spine just anterior

to the transverse carina of the sixth abdominal

tergite is bifid on both sides. The spines on the

frontal margin of the plate are not projected from

a ridge, as are the spines of the other specimens,

and they are reduced medially. On the dorsal surface of the protopod, there are spines—a single

one on the left and a bifid one on the right. The

posterior margin of each protopod has four blunt

teeth; there is a heavy spine projecting from beneath with a tiny dorsal denticle. The exopod of

the uropod has a strong laterally projecting spine

on the dorsal surface near its insertion in the protopod. There is a low rounded protuberance in

this position in all other specimens of C. ornatus.

The fifth coxal segments are more depressed and

thinner mesially in the specimen caught by the

Silver Bay. The telson of the animal from the Bahamas is not strongly lobed and has no spines on

the margins; there are no spines on the protopod,

and the posterior margin has two protuberances

with one spine underneath. The left P.2 of the

specimen from Inagua is missing, but the propodus of the right P2 has six distinct lobes, with one

subdivided for a total of seven lobes. The lobes

of P2 on other specimens of C. ornatus, while they

may occasionally be subdivided, are five in number.

The shape and lobation of the carpus of P3 is also

different. The distal part of the propodus of P3

of the male from Inagua is lobed (four distinct

lobes), whereas it is armed with irregular teeth in

other individuals. The basal segment of the antennular peduncle of the animal from Inagua lacks

the three or four spines on the external rounded

projection found in other C. ornatus.

Six of the seven females examined had the pleopods on the left side; the other specimen had them

on the right, as did the female taken by the Calypso.

Cancellus ornatus is closely related to the eastern Pacific species, C. tanneri, from which it can

be distinguished by the shape of the cheliped, the

spination of the sixth abdominal tergite, and the

relative proportions of the merus and propodus of

P2 and P;J. C. tanneri resembles C. spongicola in

that the spines are more truncate and fewer than

in C. ornatus. Also, the longitudinal groove on

the plate is more distinct in C. tanneri. The cardiac plate is wider with respect to length in C.

ornatus than in C. tanneri. The carapaces of the

C. tanneri examined look like those of C. ornatus,

and I could not detect the differences in the "triangular rostral projection" described by Benedict

(1901).
NUMBER 150 27

FICURE 8.—Cancellus ornatus Benedict. Female, si. 4.8 mm, P-708: a, sixth abdominal tergite

and telson; b, left uropod. Male, si. 6-2 mm, Sih'er Bay Sta. 3497: c, sixth abdominal tergite

and telson; d, left uropod. Male, si. 9.4 mm, G-503: e, sixth abdominal tergite and telson;

/, left uropod. Female, si. 5.5 mm, holotype, Albatross Sta. 2405: g, sixth abdominal tergite

and telson (setae omitted).
28 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

The relationship, as indicated by morphological

similarities, between C. ornatus and C. tanneri of

the western Atlantic and eastern Pacific respectively, is far closer than that between C. spongicola

and C. parfaiti of the western and eastern Atlantic, respectively. C. ornatus and C. viridis, new

species, seem to be very closely related also. (See

discussion of C. viridis.)

3. Cancellus viridis, new species

FIGURES 9-11

MATERIAL.—1 $ , 4.2 mm, cl. 6.7 mm, holotype;

P-434, north of Panama; 9°14.6'-9°13.5/N,

80°21.8-80°22.8'W; 48-49 m; in a piece of siliceous

sponge; 20 July 1966; 10' otter trawl; USNM

128732.—1 §, 4.5 mm, paratype collected with holotype; USNM 128733.

DESCRIPTION OF HOLOTYPE.—Cephalothoracic

shield only slightly wider than maximum shield

length; frontal margin of shield with rounded postorbital indentations, bordered between antennal

peduncles by continuous narrow inflated rim,

slightly broader behind ocular peduncle, armed at

lateral terminations with 2 minute denticles. Rostrum broad, sides slightly concave, exceeding lateral projections. Crescentic transverse depression

behind frontal rim, widening behind ocular scales;

swelling posterior to apex of rostrum followed by

a groove extending posteriorly, separating 2 areas

of irregular transverse ridges and grooves. Raised

sculpturing on both anterolateral edges of shield

extending mesially behind frontal rim to a point

behind ocular peduncles. Shield laterally convex,

smooth in center, especially smooth in gastric region.

Calcified part of cardiac region approximately

as long as wide; rounded posteriorly.

Ocular scales well separated, mesial two-thirds

projected anteriorly, armed with two spinules distal ly. Ocular peduncle approximately two-thirds

length of shield, slender, slightly broader proximally. Uneven row of widely spaced tubercles

with setae on dorsal surface of ocular peduncle,

curved toward inside distally. Cornea slightly inHated with basal emargination dorsally.

Antennular peduncle approximately as long as

ocular peduncle when extended. Basal segment

with 4 spines anteroventrally.

Fifth article of antennal peduncle reaching about

two-thirds length of ocular peduncle. Antennal

acicles reaching to one-half length of ocular peduncle. Left antennal acicle with 2 distal spines,

one slightly lateral to those, and one on the inner

margin (4 spines total). Right antennal acicle with

3 distal spines, one behind those on inner margin

and 2 on outer margin (6 spines total). All acicular spines projecting anteriorly.

Opercular surface of manus of cheliped tuberculate; tubercles in irregular transverse rows, appearing finer toward central longitudinal concavity.

Several tubercles larger than others, but not in distinct row. Depression extending into opercular

surface of carpus, bordered posteriorly by a projecting ridge divided into 3 tuberculate lobes with

setae on crests; anterior margin of outer carpal

lobe serrated with setae on edge. Inner face of

manus smoothly reticulate; raised crest at boundary between inner and opercular faces in approximately 6 irregular lobes, determined by small

fissures at base between lobes; tubercles obscure

lobation. Rounded knob in raised medial area on

opercular surface of manus at distal end. Inner

face of dactylus with single row of 4 small protuberances with corneous denticles near dorsal

ridge and 4 large tufts of setae.

Opercular surface of P2 tuberculate, carpus and

propodus concave, dactylus flat. Inner dorsal ridge

of carpus irregularly toothed; outer ridge divided

into 4 or 5 toothed lobes. Inner ridge of propodus

with 7 small groups of tubercles and one toothed

distal lobe; outer ridge expanded and thin, divided

into 5 or 6 overlapping toothed lobes. Inner margin of dactylus with a row of approximately ten

tubercles of diminishing height, 2 or 3 of these

paired; 5 corneous denticles on ventral border of

dactylus, one minute denticle adjacent to dark tip;

dorsal margin in approximately nine sections: 4

proximal tuberculate lobes, and 5 groups of tubercles diminishing in size to a single protuberance

distally.

Dorsal surface of carpus of P3 broadening distally, with several tubercles. Dorsal surface of propodus rough with scattered groups of 2 or 3 setae;

5 or 6 prominent teeth or tubercles on margin,

armed with accessory tubercles at base; group of

teeth and tubercles at distal end; small corneous

tooth on ventral margin of propodus at insertion

of dactylus. Dorsal margin of dactylus with a small
NUMBER 150 29

FIGURE 9. Cancellus viridis, new species. Male, si. 4.2 mm, holotype, P^t34: a, carapace; b,

left antennular peduncle, lateral view; c, sixth abdominal tergite and telson; d, fifth coxal

segments; e, left uropod. Intersex, si. 4.5 mm, paratype, P-434: /, anterior part of carapace,

eyes, acicles (setae omitted); g, sixth abdominal tergite and telson.
30 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

protuberance with several setae followed by 9 teeth

with setae, diminishing in height distally; ventral

margin with row of 6 corneous denticles and one

minute denticle adjacent to corneous tip.

P4 with oval pad of corneous granules on face

of propodus, slightly longer than wide. Dactylus

slender, subcylindrical, extending slightly beyond

distal edge of propodus, with row of corneous denticles. No spines on carpus at insertion of propodus.

Dactylus of P5 slightly more than one-third length

of propodus. Corneous pad on propodus extending

onto dactylus as double row of corneous granules.

Setae on distal part of P5 directed posteroventrally,

not plumose, serrated on distal half.

Fifth coxal segments flattened, with very shallow

central depression. Gonopores on male located anterior to depression.

Abdomen spherical; partly calcined transverse

plate on anterior and posterior part; no pleopods

on male.

Sixth abdominal tergite hexagonal, its length

slightly less than three-fourths maximum width. In

front of triangular lateral projections of transverse

carina on each side, one spine projecting anterolaterally, inserted near lateral margin. Ridge on

forward margin armed with groups of irregular

blunted teeth, approximately 10 on each side;

slight indentation in margin medially. Deep

rounded depression medially, anterior to transverse

carina. Rounded protuberances scattered over surface of plate. Posterior lobe with shallow longitudinal depression medially. Posterolateral borders serrate. Posterior margin inflated, armed with

3 to 5 small teeth.

Telson irregularly rounded, length approximately three-fourths width; surface with medial

swelling, depressed to margins; rounded protuberances symmetrically placed, one on either side of

swelling with area of pigmentation around base

of seta. Median denticle on posterior margin.

Dorsal face of protopod slightly concave. Posterior projections each with 4 small teeth, more

distinct on left side of type-specimen, and one spine

underneath. Anterior to these, one rounded protuberance with several setae.

COLOR.—The general color of recently preserved

material is green, orange, and brown markings on

a cream background. There are large green areas

on the central anterior one-third of the shield, on

the lateral margins, and just anterior to the gastric

pits. Reddish brown markings are scattered in the

depressions on each side of the semi-circular sculptured areas of the shield, at the middle of the lateral margins, and around the gastric pits.

The remainder of the shield is pale orange, as

are the ocular peduncles, antennal acicles and

flagella, and antennules. The ocular scales are

pale orange with green patches. The antennal

peduncle is light orange with a darker greenish

brown band around the middle.

The calcined part of the cardiac and branchial

regions have scattered pigmentation.

The chelipeds and ambulatory legs have green

and brownish orange markings over a pale orange

or cream background. A few reddish brown spots

are scattered on the surfaces; one is especially distinct on the inner surface of the dactylus at its insertion. The carpus and merus have more orange

color, particularly in depressions and on dorsal

margins. Green color forms a band on the distal

part of the merus of P2; the proximal part has

brownish orange markings. The green banding is

more distinct on the proximal parts of the dactylus,

propodus, and carpus of P3; the merus is green

distally and on the outside, but has more orange

and brown proximally and on the inner surfaces.

The green color is more noticeable on the outer

faces of both P2 and P3. P4 and P5 are pale with

scattered orange and green markings.

The coxal segments have green marks on a pale

orange background; there are brown areas on the

fourth segments; fifth segments are pale orange.

The maxillipeds have pigmentation around the

middle of most segments.

Some spots of pigment are in transverse lines

across the abdomen; these are associated with the

partly calcined plates.

No pigmentation is discernible on the tail fan.

All green color fades in preserved specimens;

brown areas become red, orange, or pale a year

after preservation.

The tips of the fingers of the chelipeds and ambulatory legs are dark brown to black.

TYPE.—The holotype and paratype are in the

Division of Crustacea, National Museum of Natural History, Smithsonian Institution, USNM

128732, 128733.

TYPE-LOCALITY.—Southwest Caribbean Sea,

north of Panama, P-434.
NUMBER 150 SI

a

FIGURE 10.—Cancellus viridis, new species, male, si. 4.2 mm, holotype, PH134: a, left cheliped,

lateral view; b, left pereiopod 2, mesial view; c, left pereiopod 3, mesial view.
32 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

a, b

FIGURE 11.—Cancellus viridis, new species, male, si. 42 mm, holotype, P-434: a, left pereiopod

2; b, left pereiopod 3; c, left pereiopod 5; d, left pereiopod 4. (All lateral views.)
NUMBER 150 33

ETYMOLOGY.—The name is from the Latin viridis, referring to the general greenish color of the

animal when alive or recently preserved.

DISTRIBUTION.—Known only from the typelocality.

DISCUSSION.—Cancellus viridis is closely related

to C. ornatits of the western Atlantic and C. tanneri, the eastern Pacific species. Since C. viridis

and C. ornatus occur in the same general area, it is

important to distinguish them. In life, the striking character separating the two is the green color

of C. viridis as opposed to the purple or brown

and cream color of C. ornatus.

There are morphological features which can be

used to distinguish the two species when the colors

have faded after preservation. The frontal rim is

semicylindrical in C. viridis but flattened in other

species (C. ornatus, C. tanneri, C. spongicola). The

two tiny teeth at the lateral terminations of the

frontal carina are not seen on other species (except occasionally on a large C. ornatus). The ocular

scales have a rounded projection armed with two

to four spines in C. viridis, while in C. ornatus, C.

tanneri, and most other described species, there is

only one triangular spine on each scale. C. parfaiti

may have as many as three spines arming the ocular scales, but the three-part form of the frontal

rim, granulation on the anterior part of the shield,

and lack of spination on the anterior margin of

the sixth abdominal tergite prevent confusion of

it with C. viridis. C. typus has two spines on the

ocular scale, but a divided frontal rim, hirsute appendages, and a lobed telson serve to separate it

from C. viridis. The longitudinal groove in the

opercular surface of the cheliped is as distinct in

the type-specimen of C. viridis as it is in the females of C. ornatus and much deeper than in the

males of C. ornatus. A slight concavity in the ventral margin of the cheliped of C. viridis makes the

general shape of the manus, seen in lateral view,

different from that of any other species except the

male of C. tanneri. There are tubercles on the

outer ventral margin of the palm of C. viridis, not

raised ridges as in C. ornatus and C. tanneri, nor

a patch of striae as in C. spongicola and C. parfaiti. There is only one row of corneous granules

on the inner surface of the dactylus of the cheliped

of C. viridis, as opposed to two rows on C. ornatus

and other species. The black corneous tips on the

fingers of the cheliped are not as extensive in C.

viridis as in other species. The ornamentation of

the tail fan is different (the spination is less ornate in the type-specimen of C. viridis, but the

paratype looks very much like C. ornatus). Other

characters examined in detail (ornamentation of

P;{ and P.,, relative size and shape of the cephalothoracic shield, depth of fissures on the inner dorsal

margin of the cheliped, nature of the swelling behind the rostrum) show further differences between

C. viridis and other species. The antennal acicles are

slightly longer and thinner in C. viridis when animals of the same size are compared, and the eyestalks are relatively longer in C. viridis than in C.

ornatus.

The slightly flattened fifth coxal segments of the

holotype of C. viridis are intermediate in shape

between the large rounded coxae of the male C.

spongicola and the distinctly depressed coxae of the

C. ornatus and C. tanneri males.

The paratype of C. viridis, an intersex (explained below), is nearly the same size as the holotype, but there are differences between the two

individuals. The ocular scales of the paratype are

armed distally with three and four spines. The

rostrum is more triangular than in the type, and

there is a rounded spinule at the apex. The depression behind the frontal rim is shallower between the ocular scales, and the swelling behind

the rostrum is less distinct. The cornea is noticeably wider than the slenderest part of the ocular peduncle. One of the tubercles on the ocular

peduncles is armed with a tiny spine. The left

gonopore is on the third coxal segment, and the

right one is located on the fifth segment. There

are four extremely small, poorly developed pleopods on the right side of the abdomen. These

characters suggest an intermediacy between the

male and female sex. There was no external evidence of a parasite which might have caused this

condition. The spination on the anterior margin

of the sixth abdominal tergite is very similar to

that in C. ornatus, not reduced or truncate like

the armature of the holotype.

4. Cancellus tanneri Faxon, 1893

FICURES 12-14

Cancellus tanneri Faxon, 1893:167-168; 1895:52-55, pi. xi:

figs. l-ld._Alcock, 1905:167 [list].—Gordan, 1956:306 [list].
34 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

FIGURE 12.—Cancellus tanneri Faxon, male, si. 10.7 mm, Velero III Sta. 167-34: a, carapace;

b, left antennular peduncle, lateral view; c, sixth abdominal tergite and telson; d, left uropod;

e, fifth coxal segments.
NUMBER 150 35

MATERIAL.—1 s , 4.2 mm, holotype; Albatross sta.

3368, off Cocos Island, eastern Pacific; 5°32/45//N,

86°54'30"W, 121 m; rocky bottom, taken in a piece

of coral rock; 28 February 1891; indirect examination from camera lucida sketches by B. Stolen;

MCZ 4515.—1 $, 8.1 mm; Coll. Bovallius, Pa Perlas, Panama, Central America; 11 m; stone and

coral bottom; 5 June 1882; Naturhistoriska Riksmuseum, Stockholm 50, Evertebratavdelningen, No.

5024.—1 $ 10.7 mm; Velero III sta. 167-34, Post

Office Bay, Charles Island, Galapagos; l°14'30"S,

90°28"08'W; 27 m; rock; 19 January 1934; Allan

Hancock Foundation, to be returned to USNM

collection.

DESCRIPTION.—Same as Cancellus ornatus with

the following exceptions:

Rostrum barely exceeds lateral projection.

Swelling behind rostrum sometimes not present.

Depression near lateral margins of shield, curving

toward center and widening posteriorly. Gastric

pits oval or slitlike.

Calcified portion of cardiac plate longer than

wide, rounded posteriorly.

Ocular peduncles shorter than shield, subcylindrical, smooth, broader proximally. Cornea not inflated.

Antennal acicle reaches more than one-third

length of ocular peduncle.

Terminal parts of antennal flagella broken off

(not present for examination).

Tubercles on chelipeds and ambulatory legs

rounded, not denticulate. No longitudinal row of

tubercles on opercular surface of manus. Inner

margin of dactylus with 6 to 8 corneous denticles

in upper row, 4 to 6 in lower row. As many as

10 denticles on ventral margin of dactylus of ambulatory legs. Length of merus and propodus of

P2 and P3 approximately twice or less than twice

width of these segments.

Several rows of corneous granules on dactylus of

Transverse carina on sixth abdominal tergite

with median depression. Spines on anterior margin

of tergite reduced or truncate, particularly medial

ones. Raised areas and tubercles on surface of

plate, but no spines. Teeth on posterior margin

not armed with spinules. Protopod of uropod with

2 or more rounded tubercles posteriorly; one strong

spine projecting from underneath.

COLOR.—"The calcified parts of the test are

white, spotted with red. On the eyestalks and legs

the spots show a tendency to coalesce in transverse

bands" (Faxon, 1895:54). The two preserved specimens examined were completely devoid of color.

TYPE.—MCZ 4515.

TYPE-LOCALITY.—Off Cocos Island, eastern Pacific.

DISTRIBUTION.—Known only from the locations

given for the examined material (eastern Pacific

and Gulf of Panama). In depths from 11-121 m.

DISCUSSION.—Cancellus tanneri is very closely related to C. ornatus as indicated by morphological

similarities; the only character mentioned by Benedict (1901) separating the two was the "triangular

rostral projection" of C. ornatus. The triangular

rostrum was not apparent in Faxon's published

drawings of C. tamieri. Although the type-specimen was not available to me, Miss Barbara Stolen

made camera lucida drawings of it which show the

rostrum to be triangular; the two specimens of C.

tanneri examined directly also had triangular

rostra.

Comparison of the two individuals examined

with the specimens of C. ornatus was difficult. The

female of C. tanneri has heavy encrustations of barnacles and other epifauna on her chelipeds and

ambulatory legs. Her right cheliped is smaller than

the left, but both chelipeds are shaped like those

of C. ornatus. The spines on the tail fan of the

female are strong as in C. ornatus. The male has

a tail fan with reduced truncate spines like the

type. The fifth coxae are depressed as in C. ornatus, but have a slightly different shape.

These characteristics differing from C. ornatus

are found in the two specimens and also in the

drawing of the type: the length of the outer face

of the merus and propodus of P2 and P3 is barely

twice or less than twice the width (in C. ornatus

these segments are noticeably longer than twice

the width), the calcified portion of the cardiac

region is longer than wide, and the ocular peduncles are smooth.

The black or dark brown areas on the fingers of

the chelipeds of the specimens from the Galapagos

and from Panama cover only the opposing surfaces

of the tips of the dactylus and propodus; these areas

are more extensive in C. ornatus (except for the

specimen from Inagua). The sketch of the type of

C. tanneri shows this black area about as in C.

ornatus. The extent of the black area was observed
36

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

FIGURE 13.—Cancellus tanneri Faxon, male, si. 10.7 mm, Velero III Sta. 167-34: a, left cheliped,

lateral view; b, left pereiopod 2, mesial view (outer anterior lobe of carpus broken off) ; c,

left pereiopod 3, mesial view.
NUMBER 150 37

FIGURE 14.—Cancellus tanneri Faxon, male, si. 10.7 mm, Velero III Sta. 167-34: a, left pereiopod 2; b, left pereiopod 3; c, left pereiopod 4; d, left pereiopod 5. (All lateral views.)
38 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

in C. spongicola, of which many specimens and

their moults were available, and the character

appeared variable with postmoult wear. Although

these corneous surfaces on C. tanneri were probably worn down with use, the angle of the base

of the area suggests they were never as long as those

of C. ornatus.

The abdomen of the specimens from the Galapagos and Panama is quite a bit larger than the

cephalothoracic part of the animal; the abdomen

is generally smaller (shorter) than the cephalothorax in C. ornatus. The asymmetry reported for

the type was not apparent in either of the individuals examined. Remnants of four tergites are

visible on the male as hardened areas with stronger

setae than on the rest of the abdomen. On the

female, these wide transverse strips are partly calcified near the insertion of the well-developed

biramous pleopods on the left side of the abdomen.

The corneous granules making up the pads on

the fourth and fifth legs appear to be smaller and

more numerous on the specimens from the Galapagos Islands and Panama than on specimens of

C. ornatus of comparable size. The drawings of

the holotype, however, indicate that the granules

there are more nearly the size of those on a small

C. ornatus.

The pad on the exopod of the uropods of C.

tanneri appears much broader in respect to length

than in C. ornatus. This is true for the drawing

of the type as well as the specimens.

Cancellus tanneri can be distinguished easily

from other previously described species. It differs

from C. typus in having the frontal margin of the

shield less deeply incised on either side of the

rostrum, the posterior margin of the telson straight

or rounded but not bilobed, and the fifth coxal

segments without the prominent anterior lobe.

Cancellus tanneri lacks the patch of striae on

the ventral face of the manus of the cheliped and

the postorbital depressions in the surface of the

frontal rim found in C. spongicola, C. parfaiti,

and C. typus; also, the shape of the cheliped and

the depressed fifth coxae of the male of C. tanneri

are different from other species.

According to Faxon (1893), C. tanneri is different from C. canaliculatus in having a shorter

and broader abdomen, lobate marginal crests on

the first and second pairs of legs, a more pubescent

thorax and abdomen, and short antennae. Faxon

probably had access only to Herbst's (1804) paper

showing a smooth abdomen, since the abdomen

is now missing on the type-specimen of C. canaliculatus (see discussion of C. canaliculatus). Differences in the frontal rim of the shield, spination

on the ocular scales, and the structure of the dorsolateral margin of the chelipeds, prevent confusion

of these two distinct species.

5. Cancellus parfaiti A. Milne Edwards

and Bouvier, 1891

FIGURES 15-17

Cancellus parfaiti A. Milne Edwards and Bouvier, 1891:66-

70; 1892:225; 1893:8; 1900:183-187, pi. 23: figs. 20-30.—

I'errier, 1893:1036—Akock, 1905:167 [list].—Balss, 1921:

43—Rabaud, 1941:262—Gordan, 1956:306 [list].—Forest,

1959:20, pi. 3: fig. 2; 1961:221-222.—Russell, 1962:19.—

Forest, 1966:144-145.

MATERIAL.—1 $, 5.2 mm; P-275, Annobon;

01°24'S, 05°37'E; 9-69 m; no dwelling taken; 20

May 1965; box dredge; USNM 128736.—1 $ , 9.6

mm; 1$, 10.5 mm; P-282, Annobon; 01°28'S,

05°36'E, 18-37 m; no dwellings taken; 21 May

1965; box dredge, USNM 128735, 128734 (both

illus.).

DESCRIPTION.—Cephalothoracic shield wider than

maximum shield length. Frontal margin of shield

with angular postorbital indentations. Subtriangular rostrum projecting slightly beyond blunt lateral

projections. Distinct narrow ridge immediately

behind and parallel to anterior margin of rostrum,

interrupted behind apex and at angles of postorbital indentations but continuing similarly on inner half of lateral projections. Lateral projections

with tiny denticles at anteriormost point and all

along outer margin. Several (4 or 5) small tubercles at base of rostrum in transverse line, each with

approximately 4 setae in center. Transverse channel behind rostrum extending from lateral terminations anteriorly into postorbital notches, and

posterolaterally as deep channel delimiting gastric

region. Small raised area with many setae in front

of each posterolateral extension of groove. Patch

of setae at posterolateral termination of channel.

Anterior one-fourth of shield covered with large

distinct tubercles arranged in irregular transverse

rows with scattered setae between tubercles. Entire gastric region slightly raised as round area in
NUMBER 150 39

a

a,

c

e

b, d

5

5

10

FIGURE 15.—Cancellus parfaili A. Milne Edwards and Bouvier. Female, si. 10.5 mm, P-282:

a, left uropod; b, sixth abdominal tergite and telson; c, carapace (left antennule and setae

on right side omitted) . Male, si. 9.6 mm, P-282: d, left antennular peduncle, lateral view; e,

coxal segments.
40 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

center of shield. Shallow mediolongitudinal depression extending length of shield; depression

deeper on front behind apex of rostrum, terminating posteriorly in tiny group of setae. Other symmetrically placed punctae on surface of shield,

usually associated with groups of setae. Posterior

gastric pits rounded, elongate. Anterolateral margins with many short anci long setae, several longer

setae plumose on distal half. Anterior margin

with fewer setae. Broad posterolateral indentations in shield with other sculpturing creating

three-lobed appearance.

Cardiac region longer than wide, rectangular,

calcified, with calcification decreasing posteriorly.

Five or 6 patches of setae on anterior margin.

Other symmetrically placed setose patches.

Ocular scales almost width of base of ocular

peduncle; mesial part projected as large tubercle

armed with 2 spinules (occasionally 1 or 3); projection with many fairly long setae, some of them

plumose. Several short setae on base of scale. Ocular peduncle shorter than shield length, broader

basally and distally, but narrower in middle. Several groups of setae arranged irregularly on inner

dorsal margin of ocular peduncle; 3 or 4 groups

on the outer dorsal margin. Ocular peduncle

smooth except for slightly raised areas at base of

setae. Cornea slightly inflated with curved basal

emargination.

Antennular peduncle approximately length of

ocular peduncle; antennular flagellum composed of

about 20 to 22 segments. Basal segment with 4

teeth usually.

Antennal flagellum longer than ocular peduncle.

Fifth article of antennal peduncle exceeding onehalf length of ocular peduncle. Antennal acicle

reaching middle of ocular peduncle, narrowed distally and terminating in two spines; an additional

spine on the lateral margin, and one on the inside

posterior to these. Lateral spine on basal segment

of peduncle a little larger than mesial one. Many

groups of setae and scattered setae on acicle, some

plumose.

Opercular surface of chelipeds flattened, barely

concave, granular; small protuberances at bases of

short setae on surface of palm sometimes in irregular transverse rows. Dorsal margin of carpus raised

in a crest divided into lobes; dorsalmost 2 with

tufts of setae; usually a total of 4 carpal lobes.

Inner margin of propodus slightly raised, divided

in about 6 quadrangular lobes by fissures discernible about one-third distance across palm; dorsolateral margin rounded with several tubercles on

an otherwise smooth surface; no deep channels on

this margin. Broad patch of 8 to 10 regular striae

on ventrolateral face of palm; inner surface finely

reticulate, smooth. Dactylus with several tubercles

on opercular side; on inner margin approximately

3 corneous-tipped tubercles in longitudinal row;

two rows of approximately 5 smaller corneous

projections beneath these.

Dorsal part of merus of P., with deep longitudinal furrow on distal one-third; several ridges with

tufts of short bristly setae on lateral face. Dorsolateral margin of carpus divided into 4 separate

subrectangular lobes forming a raised ridge; upper

edge with bristly setae and several small teeth; inner margin with 5 or 6 shallow indistinct fissures;

areas between fissures bristly and lightly toothed

on upper edge. Dorsolateral margin of propodus

expanded to a ridge in 5 approximately equal

lobes, separate at base, but closer at outer edge;

crest of lobes with dense patch of bristles, other

margins of lobes unarmed; inner edge of propodus

rounded, with 5 or 6 fissures; protuberances between fissures with tufts of setae. Dactylus noticeably narrower than more proximal segments;

lateral margin with small fissures proximally, short

setae on anterior edge of fissures; distal part of

outer margin smooth; inner edge with rounded

tubercles and tufts of longer setae; 6 to 10 corneous

teeth along ventral margin. Opercular surface of

dactylus flat, smooth except for raised areas around

numerous short setae; opercular surfaces of other

segments barely concave. Lateral faces of dactylus

and propodus very smooth except for occasional

small groups of setae.

Dorsal edge of carpus of P3 with approximately

five lobular projections, distal ones more protuberant; upper part of projections covered with

dense patch of setae. Dorsolateral margin of propodus forming ridge in 5 lobes with dense bristles

on upper edges; inner face with small granular

tubercles; lateral face smooth; no distinct inner

ridge; several tufts of setae along ventral margin.

Dorsal edge of dactylus with irregular protuberances and many setae; ventral margin with about

6 to 9 corneous teeth.

Corneous pad on propodus of P4 rounded distally, emarginate next to insertion of dactylus. Dae-
NUMBER 150 41

a

FIGURE 16 Cancellus parfaiti A. Milne Edwards and Bouvier. Female, si. 10.5 mm, P-282:

a, left pereiopod 3, mesial view; c, left cheliped. lateral view. Male, si. 9.6 mm, P-282: b,

left pereiopod 2, mesial view.
42

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

tylus tapering distally, armed with 2 corneous

teeth, reaching distal margin of propodus. Setae

on distal outer margins of both dactylus and propodus. Posteriorly projecting knob at base of propodus. Several protuberances and setae on dorsal

surface of carpus; occasionally a tooth near articulation with propodus.

Dactylus of Ps about one-half as long as propodus, with rows of corneous granules. Propodus

with suboval pad of corneous granules on palm.

Fifth coxal segment of males rounded, large,

with small gonopore on anteromesial margin; setae

conspicuous on anteromesial margin and anterolateral margin. Other coxal segments with symmetrically placed patches of setae.

Five partially calcified abdominal plates: the first

very small and close to the cardiac region, others

evenly spaced along dorsal surface of abdomen. Tiny

groups of setae arranged regularly over whole surface of abdomen and on abdominal plates. First

abdominal tergite of female indented, calcified;

other 4 plates hardened areas, but not calcified—

harder on left side at insertion of biramous pleopods. Pleopods with both rami partially segmented; exopod slightly shorter than endopod.

Sixth abdominal tergite, suboval, roughly hexagonal, discontinuous median depression on anterior and posterior sections of plate. Group of

setae on triangular lateral projections of transverse carina, another small group mesial to this

on anterolateral margin. Raised area with group

of setae behind and lateral to median depression

in front part of plate. Four major groups of setae

on each side of plate along posterior margin; 2 to

4 small teeth between posteriormost groups on posterior margin, 2 small teeth at posterolateral corners, another tiny tooth between anterior 2 groups

of setae.

Protopod of uropod smooth, anterolateral corner

almost divided off by deep furrow; group of setae

on anterior margin, another patch of setae just behind furrow. Posterior projection of protopod with

rounded protuberance on inside and tooth and/or

group of setae on posterolateral corner. Another

distinct tooth beneath setae on posterolateral corner. Groups of setae along all margins, upper surfaces smooth, with few setae.

Telson roughly rectangular; one or two small

teeth on the anterolateral corners; depression anteriorly on each side of raised area in center. Small

clusters of setae symmetrically arranged on surface.

Narrow longitudinal raised area in center of the

posterior two-thirds of telson. Setae of various

lengths along all posterior margins.

COLOR.—A. Milne Edwards and Bouvier (1900)

noted that all the thoracic appendages and carapace were red-orange, except for the branchial

areas and the abdomen which were whitish, with

several parts less colored or whitish.

The Pilkbury specimens are reddish orange with

large areas of pink and white. (Color notes were

made a year after preservation in alcohol, and four

years later they have faded but little. The general

patterns are still easily recognizable).

The red-orange markings on the carapace are

concentrated on the anterior one-third of the

shield, particularly in the depressions on each side.

More orange color appears around the margins of

the shield, but the broad smooth areas on the central gastric region and on each side are distinctly

pink. The cardiac region is orange. The eyestalks

and antennal acicles have pink and orange

splotches.

The orange color coalesces in incomplete bands

on the ambulatory legs. The opercular surfaces

are a more generalized pinkish hue, but this may

be due to fading. The other surfaces show the

banding; there is an indication of an interrupted

band under the palm of the chelipeds; the dactylus

has the darker red-orange color on the dorsal and

inner faces; the merus has two patches of color on

the dorsal surface. Both pairs of ambulatory legs

have an indistinct band at the articulation of the

dactylus and propodus, two bands on the inside of

the propodus, one wide distinct band on the outside of the propodus and carpus proximally, and

two obvious dark areas on the dorsal surface that

continue down onto the inside but are narrower

there. There is a colored area on each of the coxal

segments, generally in the center, but more mesial

on the fifth coxae. There is a generalized band

around the merus of both the fourth and fifth legs.

The uropods are only faintly colored, and the

rest of the tail fan is devoid of color except for

scattered small round spots of orange and a large

orange area on the middle of the posterior margin

of the sixth abdominal tergite.

TYPE.—Museum National d'Histoire Naturelle,

Paris.
NUMBER 150

43

a

FIGURE 17.—Cancellus parfaiti A. Milne Edwards and Bouvier, male, si. 9.6 mm, P-282: a, left

pereiopod 2; b, left pereiopod 3; c, left pereiopod .5; d, left pereiopod 4. (All lateral views.)
44 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

TYPE-LOCALITY.—He clu Prince (=Principe), 15

in.

DISTRIBUTION.—Off Dakar, Senegal; Annobon,

Principe, and Sao Tome in the Gulf of Guinea;

and Angola. In depths from 6-69 m.

REMARKS.—In the paper originally describing

the species, A. Milne Edwards and Bouvier (1891)

reported that specimens had been taken by the

Talisman in the regions of the Cape Verde Islands,

and that Parfait had collected that species at the

"ile du Prince" and at Annobon. There is some

question whether this location is valid, but this

cannot be determined on the basis of the literature.

The original descriptive note reported C. parfaiti inhabiting a hole in a piece of stone. Forest

(1959, 1961, 1966) reported them in clumps of

melobesiid algae. At least one of the Pillsbury

specimens was collected in a large piece of coralline alga (Holthuis, personal communication).

DISCUSSION.—All of the specimens of Cancellus

collected and reported from the eastern Atlantic

near the west coast of Africa seem to be Cancellus

parfaiti; there has never been confusion about the

identification of this animal. The divided ridge

behind the anterior margin of the carapace, the

coarse granules on the anterior third of the

cephalothoracic shield, as well as coloration and

less obvious characteristics of the ambulatory legs

and tail fan serve to separate it from any other

described species.

This species is easily distinguished from Cancellus typus

Edwards by the ornamentation in the form of quadrangular

lobes on the margins of the first pair of legs. Cancellus

(Cancer) canaliculatus Herbst is very close to the species

which we have, but differs, nevertheless, by the presence of

teeth in the area of the quadrangular lobes of which we have

spoken.

C- tanneri Faxon is very close to our species, but it lacks

the rugose area on the posterior face of the claws, its acicle

does not reach the middle of the antennal peduncles, and

its abdomen is asymmetrical. (Translated from A. Milne

Edwards and Bouvier, 1900.)

As Benedict (1901) observed, C. spongicola appears to be more closely related to C. parfaiti than

to any other species. He pointed out that a small

specimen of C. parfaiti had more deeply excavated

palms, with the inner margins a little more raised

and more distinctly cut into lobes; the triangular

median projections of the front have a distinct

raised margin, and the dactylus of the first pair of

ambulatory legs is nearly smooth, not lobed as in

C. spongicola. (See discussion of C. spongicola.)

Cancellus parfaiti, although generally similar to

C. canaliculatus (Herbst), differs from the latter

species in several easily recognizable characters

other than those mentioned by A. Milne Edwards

and Bouvier (1900): the tuberculate sculpturing

on the shield, the patch of striae on the ventrolateral surface of the cheliped, and the toothed

dorsal margin of the dactylus of P2 and P3 of C.

canaliculatus. Also the relatively smooth dorsolateral margin of the manus of the cheliped on C.

parfaiti differs from that of C. canaliculatus with

its toothed projections and distal concavity.

Alcock (1905) compared his new species, C. investigatoris, with a specimen of C. parfaiti, and

reported that the differences were extremely slight.

Thus, although they are distinguishable (see discussion of C. investigatoris), these two may be more

closely related than C. parfaiti is to C. spongicola.

According to Faxon (1893), C. parfaiti has longer

eyestalks than C. tanneri, a less pubescent thorax

and abdomen, and more protuberant coxal segments of the posterior legs. The specimens I compared did not differ appreciably in pubescence and

eyestalk length.

6. Cancellus typus H. Milne Edwards, 1836

FIGURES 18-20

Cancellus typus H. Milne Edwards, 1836:257-288, pi. 14:

fig. 3; 1837:243-244—Whitelegge, 1889a:232; 1889b: 156.—

Milne Edwards and Bouvier, 1891:70; 1893:19 Sayce,

1902:152—Alcock, 1905:167 [list].—Hale, 1927:94-96, figs91, 92—Gurney, 1939:99, 257—Hale, 1941:277-278 [juveniles], fig. 12—Pope, 1944:247-259, 7 photos; 1947:129-132,

4 illus—Dakin, 1952:199, pi. 44—Pope, 1953: 44-46, 3

photos—Gordan, 1956:306 [list].

Gryllopagurus lithodomus Zietz, 1888:298-299, pi. 14: figs. 1-4.

Cancellus lithodomus.—Alcock, 1905:167 [list].—Gordan,

1956:305 [list].

MATERIAL.— 1 s , 10.0 mm; Victoria, Australia;

before May, 1908; Grant Collection; Australian

Museum No. P334.—1 $ , 9.1 mm; Coll. Endeavour

Expedition; off Davenport and Launceston, Tasmania; before 1923; Australian Museum No.

E6670.— 1 $ , 7.8 mm; Coll. Endeavour Expedition;

Shoalhaven Bight, NSW, Australia; 15-45 fms;

before 1909; Australian Museum No. E283; USNM

71003.
NUMBER 150 45

FIGURE 18.—Cancellus typus H. Milne Edwards. Female, si. 7.8 mm, E-283: a, left antennular

peduncle, lateral view. Male, si. 10.0 mm, P-334 (not a Pillsbury station) : b, carapace (typical

antennal acicle from female added on right side, some setae on right side omitted); c, sixth

abdominal tergite and telson; d, left uropod; e, fifth coxal segments.
46 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

DESCRIPTION.—Cephalothoracic shield slightly

wider than long; anterior margin of shield bordered by semicylindrical or flattened ridge in the

shape of an obtuse W, with depressions interrupting ridge at postorbital indentations; rostrum

armed at apex with spinule, not exceeding blunt

lateral projections. Central and lateral depressed

areas behind frontal rim connected by narrow

channel behind postorbital notches; these areas

smooth with scattered setae; central depression extending short distance posteriorly between two

raised semicircular areas. Sculpturing on raised

semicircles and on anterolateral part of shield consisting of rounded or flattened irregular ridges, generally transverse, or of large tubercles in uneven

transverse rows. Heavy sculpturing only on anterior third of shield; central area smooth; many

punctae on posterolateral areas of shield. Gastric

pits elongate slits. Few setae around margins of

shield; greatest number on anterolateral borders.

Protuberance behind cervical groove with one or

two tubercles armed with several setae.

Cardiac region longer than wide; calcification almost complete except for posterior areas; approximately 5 groups of setae along front border.

Anteromesial area of branchial region calcified

with 2 or 3 well-defined groups of setae on forward

part.

Ocular scales with inner half projected to a triangle armed with one or two terminal spines; occasionally an additional spine behind the terminal

ones; many setae on projection.

Ocular peduncles much shorter than shield

length; broader basally and distally; several groups

of setae on a slightly raised line along the inner

dorsal margin. Cornea not inflated. Base of cornea barely emarginated dorsally.

Antennular peduncle reaching about threefourths length of eyestalk when extended; basal

segment with 2 or 3 teeth; flagellum composed of

about 20 segments.

Fifth article of antennal peduncle reaching approximately half or slightly more than half length

of ocular peduncle. Antennal flagellum longer than

ocular peduncle; Hagellum with as many as 24 segments. Antennal acicle reaching one-third to onehalf length of ocular peduncle, armed distally with

3 teeth, usually one additional tooth on inner

margin behind these; many setae on all parts of

acicle.

Opercular surface of cheliped flattened, slightly

concave, extremely rough and tuberculate with

many short strong setae. Dorsal margin of carpus

in several raised lobes with setae on outer surfaces

and projecting ridge. Inner margin of manus

raised, divided into 5 to 7 separate tuberculate

sections; tubercles on inner face of distalmost sections with corneous granule or denticle; dorsolateral margin rounded, channels between tubercles

deeper there, but not extending down on outer

face; several regular transverse striae on ventrolateral area of palm; on ventral margin, several

raised areas with several blunt forward-projecting

teeth and setae. Lateral surface of fixed finger and

dactylus with strong toothlike tubercles on opposing margins; several tufts of long stiff setae on both

fingers. Inner face of dactylus with two rows of 4

or 5 corneous granules; similar granules ornamenting inner surface of tubercles along dorsal margin.

Distal one-third of merus of P2 expanded on dorsal surface with longitudinal furrow. Dorsolateral

edge of carpus slightly raised, sometimes in 4 or

more distinct lobes, but fissures often very shallow

and indistinct. Opercular surfaces of carpus and

propodus concave; dactylus flat; all covered with

numerous short setae. Outer margin of propodus

raised in 5 distinct lobes, their edges seldom touching, short setae on dorsal and forward edges of

lobes; 7 or 8 groups of tubercles on inner margin

of propodus with tufts of setae from each group.

Inner and outer margins of dactylus tuberculate,

with many short setae; distinct line of corneous

denticles on ventral margin, tufts of setae in rows

on either side of line.

Merus of P3 broad, flat. Carpus with several

forward-projecting lobes and setae distally, reduced

proximally. Lateral margin of propodus with approximately 5 toothed projections, patches of

strong setae on crests and smaller ones on inner

and ventral surfaces in several longitudinal rows;

denticle on distal ventral margin; some setae on

external face. Dorsal margin of dactylus tuberculate with many laterally projecting setae; shorter

setae in many clusters on inner face, few on outer

face; row of tufts of setae ventrally on either side

of line of 4 to 8 corneous denticles.

Round pad of corneous granules covering most

of distal surface of propodus of P4, several tufts of

setae on proximal uncovered portion. Dactylus not

reaching end of propodus, with a row of granules
NUMBER 150 47

FIGURE 19.—Cancellus typus H. Milne Edwards. Male, si. 10.0 mm, P-334 (not a Pillsbury

station) : a, left pereiopod 2, mesial view; c, left pereiopod 3, mesial view. Female, si. 7.8

mm, E-283: b, left cheliped, lateral view.
48 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

and a few tufts of setae. Carpus with tooth on dorsal distal margin near the articulation with propodus; setae in groups along dorsal margin.

Po with elongate pad of corneous granules on

propodus, one row of granules extending onto fixed

finger; dactylus with two irregular rows of granules and setae. Many long setae on all margins.

Female gonopores large, round, mesial on the

proximal part of coxae of P3.

Front borders of basis, coxa, and ischium of P4

with heavy fringe of long, plumose setae.

Male gonopores (on inside anterior edge of the

forward projection of the coxae of P3) much

smaller than those of female; coxal projection expanded and thin anteromesially; broad depression

in center of segment; many short setae on front

margin on either side of and beneath gonopore.

Four hardened transverse strips across abdomen

(remnant of first abdominal tergite close to junction with carapace). Tiny groups of setae arranged

evenly over whole surface of abdomen. Females

with four well-developed biramous pleopods on

one side of abdomen; exopod usually shorter than

endopod; anterior pleopods partly calcified.

Sixth abdominal tergite with a shallow median

depression in front of transverse carina. Anterior

lobe of plate depressed to lateral margins; anterior

margin bordered by slight swelling on either side

of midline; rounded tooth lateral to the swellings;

lateral tooth on each side in front of carina; median longitudinal depression on posterior section;

2 to 4 rounded teeth on each posterolateral margin,

several teeth mesially on posterior border. Small

dusters of short setae evenly placed over entire

surface of plate; several groups of longer setae on

posterior margins.

Uropods covered with tiny clusters of setae; protopod smooth; posterior projection armed with

only one lateral tooth and large round protuberance mesially. Setae along all margins of exopod

and endopod much longer than those covering surface.

Telson with scalloped border creating a bilobed

effect. Occasionally a few teeth on anterolateral

borders; slight swelling medially with depressed

areas anterolaterally. Longer setae on posterior

margins.

COLOR.—"The color in spirit specimens is reddish, and especially the limbs are marked with

large dark red spots, some of them encircling the

legs, forming bands. . . . The pericardial cavity is

marked by the branchio-cardial groove as a red

shield. The branchial regions are of a pale horny

color" (Zietz, 1888:298).

The preserved specimens available for examination had lost all traces of color.

TYPE.—Not in Museum National, Paris. Presumed lost.

TYPE-LOCALITY.—Unknown.

DISTRIBUTION.—Australia: off Port Jackson and

Port Phillip, St. Vincent Gulf; and off Devonport,

Tasmania; sublittoral.

REMARKS.—This species is not uncommon just

below the low watermark of the southern shores of

Australia. It has been included in several popular

works under the common names of "miner hermit

crab" (Hale, 1927) and "boring hermit" (Dakin,

1952), referring to its alleged habit of drilling its

own hole in the stone used for its dwelling. Zietz

(1888) said that the animal lived in "self-made

burrows in loose stones." He further noted that

the collector of his specimens observed that the

crabs did not drag their dwelling about with them.

In her magazine articles, Pope (1944, 1947) cornminted on C. typus' habit of living in a hole excavated in a stone or, occasionally, in a clinker (a

coal cinder). She reported that when the animal

moved about, the stone was dragged along too.

In a more extensive article, Pope (1953) noted

from records of the Australian Museum that one

Cancelhis had extended its burrow so far back into

the pebble that it had just broken through on the

upper surface of the stone. "The crustacean had

discovered the mistake, however, and had begun to

turn the end of the burrow slightly downwards,

away from the surface." Pope felt that this supported the theory that the crab made the excavation and that it does not merely appropriate a

hollow stone left by some previous occupant.

Hale (1941) briefly described and figured an

early stage of C. typus from juveniles clinging to

the abdominal appendages of a female. This and

an earlier mention of the same female (Hale,

1927) are the only reports of the young form of a

species in the genus Cancelhis other than an aberrant species, C. macrothrix, and indicates that development is direct. Gurney (1939) based his

report of direct development in C. typus on Hale's

(1927) paper.

DISCUSSION.—The type-species of the genus Can-
NUMBER 150 49

FIGURE 20.—Cancellus typus H. Milne Edwards, male, si. 10.0 mm, P-334 (not a Pillsbury

station) : a, left pereiopod :">; b, left pereiopcxl 4; c, left pereiopod 2; d, left pereiopod 3.

(All lateral views.)
50 SMITHSONIAN CONTRIBUTIONS TO /OOLOGY

cellus was described from one male specimen from

an unknown location. Dr. L. B. Holthuis confirmed the possibility that H. Milne Edwards could

have had material from Australia. It seems that

Zietz did not consider the possibility of his new

species being a Cancellus when he named Gryllopagurus lithodomus. Whitelegge (1889a) indicated

that "Grallograpsus lithodomus Zietz" [sic] was the

same species as C. typus Milne Edwards. He gave

a complete bibliographical reference to Zietz' 1888

paper, and it cannot be demonstrated that this

name change was intentional. Thus, Grallograpsus is an incorrect subsequent spelling, and, according to the International Code of Zoological

Nomenclature, has no nomenclatural status. Na

commentary accompanied Whitelegge's (1889a)

synonymy, and there has been little question since

about the name of the Australian species. Alcock

(1905) did not treat Cancellus lithodomus, but simply listed it in his table of species, as did Gordan

(1956).

The only specific character mentioned in H.

Milne Edwards' (1836, 1837) descriptions of C.

typus is the wide squamiform structure of the basal

article of the last pair of legs which shows up

clearly in his illustration. Zietz (1888), too,

pointed out a "shovel-shaped prolongation" on the

basal article or coxa of the fourth pair of ambulatory limbs. The bilobed nature of the telson is

also apparent on Milne Edwards' figure. The frontal rim of the carapace on either side of the rostrum seems to be more deeply indented than in

Zietz' (1888) or Hale's (1941) drawing of the anterior margin. In any case, the raised rim is not

continuous between the lateral teeth. Actually,

H. Milne Edwards' drawing of the rostrum of C.

typus looks more like that of C. parfaiti, as does

Hale's; Zietz' drawing looks like the rostrum of

C. ornatus. All three specimens examined had the

frontal rim in three distinct sections.

According to other authors, C. typus can be distinguished from C. parfaiti by the latter species'

quadrangular lobation of margins of the first pair

of legs (Milne Edwards and Bouvier, 1900), from

C. ornatus and C. tanneri by the anterior projection of the fifth coxal segment (Benedict, 1901 and

Faxon, 1893), and from C. tanneri also by the

notched telson and the deeply incised margin of

the carapace (Faxon, 1893).

The external morphology of C. typus is more

similar to that of C. parfaiti, the eastern Atlantic

species, than to any other Cancellus examined.

Some of the characteristics shared by these species

are the general shape and lobation of the chelipeds

and ambulatory legs and the smooth anterior margin of the sixth abdominal tergite. These two can

be distinguished easily, however, by the expanded

fifth coxal segments of the male, the lobular telson, and hairy surfaces on the tail fan of C. typus,

as opposed to the rounded coxal segments, rectangular telson, and relatively bare tail fan of C.

parfaiti.

No other species examined has the numerous

clusters of short setae present on C. typus. This

character is particularly noticeable on the inner

surface of the dactylus of P3, on the abdomen, and

on all parts of the tail fan.

All females reported previously had pleopods on

the left side; one of the two females examined

here had them on the right.

Among the differences noted between the male

and female specimens examined were the expansion of the coxal segments of the male, and the

bifid nature of the ocular scales on the females

(this scale has a simple, triangular projection in

the male). Also, the females had even shorter

ocular peduncles than the male.

7. Cancellus canaliculatus (Herbst, 1804)

FICURES 21, 22 (part)

Cancer canaliculatus Herbst, 1804:22, pi. 60: fig. 6.

Pagurus canaliculatus—Olivier, 1811:647.—H. Milne Edwards, 1836:287; 1837:244.

Cancellus canaliculatus.—Milne Edwards and Bouvier, 1891:

70._Alcock, 1905:167 [list].—Gordan, 1956:305 [list].

MATERIAL.—1 $ , si. 6.2 mm, cl. 9.0 mm, sw. 7.7

mm, holotype, Indian Ocean.

DESCRIPTION OF HOLOTYPE.—Cephalothoracic

shield shorter than maximum width (sl./sw. =

0.8), laterally convex, frontal margin with angular

postorbital indentations. Subtriangular rostrum

unarmed, not projecting beyond blunt lateral projections. Anterior margin between antennal acicles

with semicylindrical ridge interrupted by depressions at postorbital indentations. Depressed areas

behind lateral extensions of frontal rim connected

by narrow transverse channel. Medial swelling anterior to this channel; mediolongitudinal groove
NUMBER 150 51

FIGURE 21.—Cancellus canaliculatus (Herbst) . Male, si. 6.2 mm, holotype, "East Indies":

a, carapace; b, left chcliped, lateral view; c, left pereiopod 2, mesial view; d, left pereiopod 2,

lateral view; e, left pereiopod 4, lateral view; /, left antennular peduncle, mesial view. (Apparent length difference between two views of pereiopod 2 is due to illustration angle.)
52

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

between two raised sculptured areas. Similar sculpturing laterally on anterior one-fourth of shield.

Remainder of shield smoother, with scattered punctae at bases of setae. Indentation on each side of

shield just posterior to center of lateral lobe; slight

concavity in shield posterolaterally on line between

indentation and round gastric pits. Most setae

broken off; remnants of some setose fringe on anterolateral margins.

Cardiac region approximately square, corners

rounded; calcification appearing complete. Some

setae remaining on front border. Punctae indicating scattered setae and groups of setae.

Anteromesial area of branchial region heavily

calcified with several groups of setae near anteromesial margin.

Ocular scales with inner half broadly projected,

armed with 4 or 5 terminal teeth; projection with

setae, especially at termination.

Ocular peduncles and antennules missing on

type-specimen.

Antennal acicle armed with one or two teeth

distally, 2 teeth anterolaterally and one tooth on

inner dorsal margin; basal segment indented and

armed with 2 swollen teeth. Setae on all parts of

acicle. Antennal peduncle and flagellum missing.

Opercular surface of cheliped slightly concave;

evenly tuberculate. Concavity more distinct on

opercular surface of carpus, bordered posteriorly

by raised toothed ridge; fissure perpendicular to

opercular surface dividing one anterolateral lobe

from remainder of carpus; anterior margin of this

lobe with small rounded teeth and setae. Dark

depressions on lateral and mesial surfaces of all

segments, indicating clusters of setae present at

one time. Furrows between toothed protuberances

on dorsolateral margin of manus more distinct distally, protuberances becoming small overlapping

lobes on distal projection of anterolateral corner

of manus; concavity in outer surface below lobes

accentuating projection. Raised area with scattered

small tubercles mesial to projection on opercular

surface. No patch of parallel striae on ventrolateral surface of manus. Crest between opercular

and inner surfaces of manus raised, divided into

f) or 7 tuberculate lobes, indications of tufts of

setae between lobes, several corneous granules on

tubercles on inner face of distal lobes. Similar

corneous granules on groups of large tubercles on

inner dorsal margin of dactylus, another row of

tiny granules below tubercles on dactylus. Dorsolateral margin of dactylus with border of larger

tubercles than those on opercular surface. Tips of

finger eroded away on both chelipeds of holotype.

Opercular surface of P^ flat to slightly concave;

finely tuberculate medially, tubercles larger on borders. Distal part of dorsolateral surface of merus

expanded with furrow on flat surface. Dorsolateral

margin of carpus raised, divided into 4 lobes

toothed on upper edge; inner dorsal ridge irregularly toothed. Dorsolateral margin of propodus

expanded, divided into 5 distinct lobes, their edges

very close, toothed with tufts of setae on dorsal

edges; swelling with forward projecting setae near

base of some lobes on lateral surface, below this,

row of groups of setae, more distinct proximally;

inner ridge with several groups of tubercles; tufts

of forward-projecting setae on ventral margin. Dorsolateral margin of dactylus in approximately 4 or

5 shallow lobes, lobes finely toothed; inner margin

obscured by dried, cemented setae.

Dorsal edge of P;j with several toothed projections, more prominent distally, with tufts of

forward-projecting setae. Lateral to projections 3

depressions with clusters of setae in longitudinal

row. Dorsal margin of propodus slightly expanded,

divided into 5 sections: one proximal toothed projection and 4 distinct toothed lobes with setae;

tufts of setae on lateral face below fissures between

lobes; inner surface with several groups of setae in

irregular longitudinal rows; ventral margin with

many large tufts of setae. Dorsal margin of dactylus irregularly toothed, 4 proximal groups almost

lobate; tufts of setae between teeth; inner surface

with many groups of short and long setae; ventral

margin with 4 large tufts of setae and 3 or 4 corneous denticles.

P4 with round pad of corneous granules covering

outer distal face of propodus. Dactylus not extending to end of propodus, with terminal corneous denticle and one just proximal to it mesially.

No spine on carpus at insertion of propodus.

TYPK.—Zoologisches Museum Berlin No. 2451.

TYPE-LOCALITY.—"East Indies."

DISTRIBUTION.—Known only from the typelocality.

REMARKS.—The holotype was dried and glued to

paper; many appendages were disarticulated and

placed incorrectly on the specimen. Some body

parts were missing completely, notably the eye-
NUMBER 150 53

FIGURE 22.—Cancellus canaliculatus (Herbst), male, si. 62 mm, holotype, "East Indies":

a, left pereiopod 3, mesial view; b, left pereiopod 3, lateral view. Cancellus macrothrix Stebbing, female, cl. 21, holotype, Algoa Bay: c, anterior carapace (redrawn from Stebbing, 1324,

plate 3) ; d, sixth abdominal tergite, telson and uropods (redrawn from Barnard, 1950:448,

fig. 82, setae on uropods and telson omitted).
54 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

stalks, right P2, both P5, antennae, antennules, abdomen, uropods, sixth abdominal tergite, and

telson. This substantiates Benedict's (1901) suggestion that Herbst (1804) had added a typical

pagurid abdomen to his illustration, since the abdomen was lacking on the type-specimen. In most

cases tufts of setae were missing and dark areas or

pits served to indicate their position. These were

not reconstructed on the illustrations. Although

the last pereiopods, P5, were missing entirely, the

holotype was a male, determined by the absence of

gonopores on the coxae of P3.

DISCUSSION.—This species has not been definitely

reported since the original description. The note

given by Herbst was very brief, and while there is

little doubt that the Cancer canaliculatus he described and figured was a Cancellus, the information he presented is not specific. Beyond describing

the general shape of the appendages, Herbst said

the hands were concave with toothed margins and

the second and third segments on the first pair of

legs were concave. The color was described as

white with red spots, with the red color forming a

band on the legs. The one small drawing of the

crab shows the abdomen narrowed posteriorly with

several constrictions and dark lines indicating at

least five segments. Benedict (1901) commented on

this departure from the usual spherical shape of

the abdomen: "The abdomen in this genus seems

to be even more readily separated from the thorax

than in other genera, and this separation had not

unlikely taken place in Herbst's specimen and the

conventional form may have been added to the

figure for the sake of completeness." He added

that Herbst had substituted an incorrect part in

another well-known work. No location data was

given other than "east Indies."

The holotype of C. canaliculatus differs in the

structure of the cheliped from all other Cancellus

examined. The toothed projections and the small

distal lobe on the dorsolateral margin of the manus

are found in no other species. Also, an interrupted

frontal rim and transverse sculpturing rather than

tubercles on the shield do not occur together on

any other species except C. spongicola, and the

latter species has a patch of striae on the cheliped

not present in C. canaliculatus.

Cancellus canaliculatus can be distinguished

from C. investigatoris, the other "east Indian" species, by the following characters: C. canaliculatus

has the frontal margin inflated and divided into

three parts with no depression in the margin behind the rostrum, the basal segment of the antennal acicle armed with two heavy teeth, no

distinct denticles at rostral apex or lateral projections (none on holotype; however, these may have

been broken off if they were present at one time),

and three or four teeth on the basal segment of the

antennular peduncle; C. investigatoris has a fourpart ridge behind the frontal margin, three or more

teeth on the basal segment of the acicle, distinct

denticles at the rostrum and lateral projections,

and only two sharp teeth on the basis of the antennular peduncle. Also, C. investigatoris lacks

the distinctive toothed projections on the distal,

dorsolateral margin of the manus of C. canaliculatus, but has the ventrolateral patch of striae that

is missing on C. canaliculatus.

8. Cancellus investigatoris Alcock, 1905

FIGURES 23-25

Cancellus investigatoris Alcock, 1905:77-78, 167 [list], pi. 5:

fig. 8.—Southwell, 1906:217; 1910:179-184, pis. 1, 2; 6

figs.—Gordan, 1956:305 [list].

MATERIAL.—1 $ , si. 7.8 mm, cl. 10.0 mm, sw.

8.8 mm; Sagami Bay, Kannon-zuka-dashi, Japan;

62 m; in calcareous rock; 20 January 1959; Biological Laboratory of the Imperial Household

(BLIH), No. 9.

DESCRIPTION.—Cephalothoracic shield shorter

than maximum shield width (sl./sw. = 0.9), laterally convex. Frontal margin with angular postorbital indentations; subtriangular rostrum armed

with tiny denticle at apex, not exceeding lateral

projections; a single denticle at apex of each lateral projection. Distinct narrow ridge just posterior

and parallel to anterior margin of rostrum, interrupted behind apex and at angles of postorbital

indentations, but continuing similarly on inner

half of lateral projections. Several groups of setae

arranged symmetrically in depressed areas behind

rostrum and lateral projections; medial depression

extending posteriorly, terminating in larger group

of setae separating two sculptured semicircular

areas. Depressions lateral to raised sculptured

areas, also terminating posteriorly in group of setae; smaller groups of setae scattered in depressions

and concavities of sculptured surface. Sculpturing
NUMBER 150 55

FIGURE 23.—Cancellus investigatoris Alcock, female, si. 7.8 mm, BLIH No. 9, Sagami Bay: a,

carapace; b, coxal segments; c, left antennular peduncle; d, sixth abdominal tergite and telson;

e, left uropod. (Setae on coxal segments, antennular peduncle, and right side of carapace

omitted.)
56 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

consisting primarily of irregular swellings with upper surface slightly projected like the frontal rim,

often forming crescents with concavity anterior.

Similar sculpturing anterolaterally; central gastric

region relatively smooth, with several punctae at

bases of small groups of setae. Posterolateral margins slightly concave; anterior to concavity, two

channels directed posteromesially from lateral

edge of shield. Gastric pits elongate, rounded anteriorly, pointed posteriorly. Anterolateral margins

with numerous setae, many of them plumose. Anterior margin with fewer setae.

Cardiac region subrectangular, slightly wider

than long. Two wide transverse patches of long

setae on anterior margin of plate; several distinct

groups of setae in longitudinal row along lateral

margins.

Anteromesial area of branchial region calcined

with 5 or 6 groups of long setae near anteromesial

margin.

Ocular scales broad at base, with inner half projected anteriorly and armed with 3 or 4 teeth distally, several setae on dorsal surface of projections;

many long plumose setae on anterior margin.

Length of ocular peduncle about one-half shield

length; slightly narrower in middle. Several groups

of short setae on dorsal surface; proximal half of

inner margin with longitudinal row of projections:

the proximal 2 distinct curved teeth, distal ones

diminishing to rounded tubercles; groups of strong

setae between projections, some plumose. Cornea

with slight basal emargination, not as wide as distal part of ocular peduncle.

Antennular peduncle when extended not reaching cornea; flagellum with approximately 16 segments. Basal segment with 2 sharp anteriorly

projecting teeth and one anteroventral protuberance.

Antennal flagellum only slightly longer than

ocular peduncle. Fifth article of antennal peduncle exceeding one-half length of ocular peduncle.

Antennal acicle setose, narrowed distally, armed

with 2 terminal teeth, the inner longer than the

outer; 2 teeth posterior to these: one on outer margin, one on inner. Basal segment with 3 or 4 teeth.

Opercular surface of cheliped flat; evenly covered

with denticulate tubercles and short setae. Opercular face of carpus concave; dorsal margin projected into 3 toothed lobes; anterolateral lobe most

distinct, fissures between other two not as deep,

anteromesial lobe subdivided by several distinct

irregular fissures; many short strong setae on projecting edge. Inner margin of manus divided in

approximately 6 quadrangular lobes by fissures extending about one-fourth distance across face of

palm: middle 4 lobes small, well separated, proximal and distal lobes larger, subdivided by shallower, less distinct fissures; inner surface of distal

lobes with many small protuberances with setae,

some with small corneous denticles; dorsolateral

margin rounded, tubercles with setae extending

short distance on lateral face. Ventrolateral surface

of palm with rugose area of 9 regular striae; ventral extension of some striae toothed with setae,

particularly sixth and ninth striae from distal end;

one or more teeth with setae in a group on ventral

surface just mesial to distalmost stria; large tufts

of setae near corneous tips of propodus and dactylus. Inner face of manus smooth with scattered

short setae, sometimes slight swelling at base of

seta. Dactylus tuberculate on opercular side; inner

dorsal margin with a few bifid corneous denticles

on tubercles; below these on inner face, 2 longitudinal rows of 5 or 6 corneous denticles, most of

them bifid.

Opercular surface of P2 slightly concave; tuberculate, with short strong setae scattered evenly on

surface, many tubercles denticulate. Ventral margin of merus with many small curved teeth. Dorsolateral margin of carpus slightly raised, divided in

4 or 5 lobes, toothed on dorsal edge with tufts of

setae; several fissures dividing inner margin in

groups of toothlike tubercles. Dorsolateral margin

of propodus expanded, divided in 5 well-separated

lobes: occasionally one subdivided to form more

lobes; dense setae on outer crest and anterior edge

of lobes; inner margin with 6 or 7 tufts of setae

ventrally; 3 or 4 small teeth on distal margin of

lateral face. Dactylus flat, dorsolateral margin irregularly toothed; inner margin with fissures separating 5 to 10 protuberances with setae; 6 or 7

corneous teeth along ventral margin.

Dorsal margin of carpus of P3 with 4 anterodorsal projections: distal one or two lobulate; tufts of

setae and several teeth along dorsal margin. Dorsolateral margin of propodus divided into 4 or 5

lobes: distal one larger, proximal one or two

smaller; lobes tuberculate with setae on dorsal

edge; inner face smooth, with scattered groups of

2 or 3 setae in rows; several teeth on distal margin
NUMBER 150

a

57

FIGURE 24 Cancellus investigatoris Alcock, female, si. 7.8 mm, BLIH No. 9, Sagami Bay:

a, left cheliped, lateral view; b, left pereiopod 2, mesial view; c, left pereiopod 3, mesial view.
58 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

of lateral face. Dactylus smooth, flat, with longitudinal rows of groups of setae; outer margin irregularly toothed; tufts of setae just lateral to

dorsal margin; 3 to 6 corneous denticles and 4

large tufts of setae on ventral margin.

Dactylus of P4 not extending to distal margin of

propodus, terminating in corneous denticle and

tufts of setae; 2 or 3 proximal to this on mesial

margin. One distinct curved tooth on anterodistal

margin of carpus.

Dactylus of P5 less than one-half length of propodus; row of 2 or 3 corneous granules extending

onto dactylus from subrectangular pad of granules

on propodus.

Abdomen semispheroidal, 4 transverse strips of

clear material across abdomen, partially hardened

at insertion of well-developed pleopods on female.

Sixth abdominal tergite suboval, barely hexagonal; lobe of plate anterior to transverse furrow

larger than posterior lobe; posterior lobe with medial longitudinal depression; lateral projections of

transverse carina rounded, group of setae just anterior to these on each lateral margin; several low

tubercles with setae on anterolateral margin; short

setae scattered over surface; several rows of setae

along posterolateral margins.

Protopod of uropod smooth, groups of short

setae on surface; posterolateral projection with

rounded protuberance mesially, very weak tooth

and group of setae on posterolateral corner;

stronger tooth beneath setae. Exopod with 2 large

rounded protuberances dorsally near insertion to

protopod.

Telson roughly rectangular; dorsal area smaller

than that of sixth tergite; anterior part of plate

wider than posterior; many groups of short setae

arranged symmetrically on surface; a central swelling with depressed areas anterolaterally. Long setae

bordering posterolateral and posterior margins;

many tufts originating just inside margins. An

indentation posterolaterally. Posterior margin concave.

TYPE.—Indian Museum 1629/7. Reported by

Dr. B. K. Tikader (personal communication) to

be in extremely bad condition.

DISTRIBUTION.—Indian Ocean, off the southeast

and west coasts of Ceylon, Gulf of Mannar, shallow

water, 13 m; Sagami Bay, Japan, 62 m.

DISCUSSION.—The female specimen of C. investigatoris from Sagami Bay differs from specimens of

C. parfaiti in the following characters: C. investigatoris has three or four spines on the raised dorsal

edge of the antennal acicle (the specimen examined has three spines on the left and four on the

right), deflated corneas, ocular peduncles approximately one-half shield length, broad prolongation

of the ocular scale, spines on the mesial proximal

surface of the ocular peduncles, distinct spinules

at the rostrum and lateral projections, two sharp

teeth on the anterior margin of the basal segment

of the antennular peduncle, one or more low,

toothlike protuberances on the anterolateral margin of the sixth abdominal tergite, and no teeth

or tubercles at the anterolateral margins of the

telson; C. parfaiti has only two spines on the dorsal

edge of the antennal acicle, inflated corneas, the

ocular peduncles two-thirds to three-fourths shield

length, narrow prolongation of the ocular scale,

smooth ocular peduncles, spines at the rostrum and

lateral projections indistinct or lacking, four teeth

projecting from the anterolateral margin of the

basal segment of the antennular peduncle, the

anterior margin of the sixth abdominal tergite

smooth, and tubercles or teeth at the anterolateral

margins of the telson. These differences are listed

to show that C. investigatoris and C. parfaiti are

distinguishable morphologically rather than to

discredit the point Alcock (1905) was making by

emphasizing their similarities. The two species are

quite similar in many characters and are probably

more closely related than any other species in the

C. typus complex. Alcock mentioned that there was

no patch of striae on the inner surface of the palm,

but he did not describe, nor did his illustration

show, the distinct patch on the ventrolateral

surface that C. investigatoris has in common with

C. parfaiti. Also the frontal margin appears to be

continuous in Alcock's illustration, rather than interrupted at the rostral apex and behind the ocular

scales as it is in the specimen from Sagami Bay,

as well as in C. parfaiti. Although Alcock's description and illustrations were not specific, he noted

that the differences between C. investigatoris and

a specimen of C. parfaiti were very slight. This

indicates that he had a new species rather than a

specimen of C. canaliculatus (Herbst), the only

other species described from that area. Therefore,

although the holotype of C. investigatoris could not

be examined, it is reasonable to conclude that the

specimen described here is indeed C. investigatoris.
NUMBER 150 59

FIGURE 25 Cancellus investigatoris Alcock, female, si. 7.8 mm, BLIH No. 9, Sagami Bay: a,

left pereiopod 2; b, left pereiopod 3, c, left pereiopod 4; d, left pereiopod 5. (All lateral views.)
60 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

A summary of the differences between C. investigatoris and C. canaliculatus appears in the discussion section of the latter species account.

The only other occurence of C. investigator is was

reported by Southwell (1906). One specimen was

taken in shallow water in the Gulf of Mannar

(between the west coast of Ceylon and the southern

tip of India). Later (1910), Southwell described

the modification of the chelipeds to form an operculum for the hole of the crab. He reports:

During a survey of the Ceylon pearl banks this specimen

was dredged up, occupying a small cavity on the ventral

edge of a flattish lobulated piece of Porites arenosa four

inches in diameter. . . . The terminal portion of the abdomen could be slightly protruded through a very small

hole situated a little nearer the basal centre of the coral,

and the specimen could turn completely round in its shelter.

The tube appeared to be lined with reddish Nullipore

(Lithothamnion) .

The location was given as west coast of Ceylon, in

7 fathoms. The indications are that this was the

same specimen reported in 1906.

9. Cancellus macrothrix Stebbing, 1924

FIGURE 22 (part)

Cancellus makrothrix Stebbing, 1924:240-241, pi. 3.—Barnard, 1950:447-450, fig. 82-

Cancellus macrothrix.—Gordan, 1956:305 [list].

MATERIAL.—None

DESCRIPTION.—

Most parts of the body and appendages strongly hirsute.

Rostrum broad and very short, but acute and distinct.

Frontal margin rather strongly costate, the costa interrupted

at the shallow notch between rostrum and the very obtuse

submedian points. Behind the costa a transverse crescentic

groove, and a short medio-longitudinal groove. Eye-stalks

equal to anterior width of carapace (i.e. between the very

obtuse anterolateral angles), and extending slightly beyond

apex of extended peduncle of ant. 1 (by about length of

cornea), slender, dilated at base, but swelling only very

slightly distally, setose. Ocular scales L-shaped, apically

acute, closely approximate or contiguous. Apex of peduncle

of ant. 2 reaching half-way along eye-stalk, acicle reaching

nearly to end of last joint of peduncle, acute, 2 spinous

tubercles on outer margin, and one on inner margin, with

numerous bristly hairs; flagellum about as long as length

of anterior (calcined) part of carapace, its joints with whorls

of short setules. Chelipeds and 2nd and 3rd legs thickly

covered on their anterior surfaces with stiff bristly hairs

arranged in tufts, and on the hands of the chelipeds more

or less in longitudinal lines. Inner upper margin of hands

and lingers with a few blunt (mostly dark-tipped) tubercles,

and on the inner surface of the fingers below the upper

margin two additional rows of tubercles (4-5 in each row).

Inner upper margin of 5th joint of 2nd leg with 7-8

denticles, of 6th joint more or less scalloped owing to the

insertion of bristle-tufts. Sixth and 7th joints of 2nd and

3rd legs subequal. Biramous appendages in $ on left side

of abdominal segments 2-5 (in the single $ specimen the

abdomen is missing) . Left uropod slightly longer than right;

6th abdominal segment calcified, transversely divided by a

deep groove, granulose and setose, its distal margin overhanging base of telson, margin denticulate, a broad quadrangular lobe projecting slightly beyond the postero-lateral

corners. Telson about as broad as long, or slightly longer

than broad, asymmetrically subcircular, a semicircular shallow groove and a few granules and setules on upper surface,

margin strongly setose, and (in one specimen) with a few

calcified denticles. (Barnard, 1950:447^48.)

TYPE.—South African Museum No. A1541.

TYPE-LOCALITY.—Algoa Bay (off South Africa),

18.3 m.

DISTRIBUTION.—Off South Africa: Cape Morgan,

East London, Aloga Bay.

REMARKS.—The specimens from East London

and Cape Morgan examined by Barnard (1950)

were housed in Murex shells. This species has been

reported from 18-31 meters.

DISCUSSION.—

This species is a very aberrant one, if it is to be regarded

as a Cancellus. Both the 2nd and also the 3rd pairs of

legs participate with the chelipeds in closing the aperture

of the mollusc shell, and in conformity with this unusual

habitat the abdomen is spirally coiled to an extent equal

to that of any other shell-inhabiting Hermit-crab. The

uropods, however, remain nearly symmetrical. The upper

distal corner of the wrists of the chelipeds does not project

so strongly (knuckle-like) as in more typical species, and

the anterior surface of the hand, though flat, is scarcely

concave. The carapace is widened posteriorly. The ocular

scales are closely approximate, in fact contiguous. (Barnard,

1950:449.)

Cancellus macrothrix can easily be distinguished

from the other Cancellus by almost any of the characters just described.

The form of this species may show characters

more primitive than those of other members of

the genus Cancellus. Certainly the spirally coiled

abdomen, slightly asymmetrical tail fan, flattened

opercular surface of the cheliped (rather than concave), and only weakly projected carpus are characters intermediate between those of the more

typical pagurids and those of Cancellus.

In his opening remarks, Stebbing (1924) noted
NUMBER 150 61

that the leading character in the original definition

of the genus was the symmetry of the pleon. He

then referred to Faxon's (1895) statement about

the partial asymmetry of Cancellus tanneri and to

Alcock's (1905) remark that the telson was symmetrical ". . . or nearly so. . . ." It appears

that Faxon's specimen is the only asymmetrical

Cancellus that had been reported; the tail fans of

specimens of C. tanneri examined by this author

were symmetrical.

Barnard's (Cancellns-like) description of the

rostrum and frontal margin of the carapace do not

agree with Stebbing's rough sketch (pi. 3, figure

of carapace, redrawn in Figure 22, this paper)

which is more like pagurids of other genera.

Barnard (1950) described eight juveniles attached or "adhering" to various parts of the abdomen and sides of the carapace of a female

specimen; two were still enclosed in the egg membrane, the other six were free and stated to be

in the "glaucothoe stage." He concluded that in

C. macrothrix, the free-swimming zoeal stage was

suppressed and the larvae developed up to the

glaucothoe stage within the mother's dwelling.

This agrees with the direct development reported

by Hale (1941).

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the Collection of the Indian Museum, Part II:

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62 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

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