THOMAS PHEU A Field Guide to the

^f Cidaroid Echinoids

^f of the Northwestern

: Atlantic Ocean,

Gulf of Mexico, and

the Caribbean Sea

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY • 1970 NUMBER 40
SERIAL PUBLICATIONS OF THE SMITHSONIAN INSTITUTION

The emphasis upon publications as a means of diffusing knowledge was expressed

by the first Secretary of the Smithsonian Institution. In his formal plan for the Institution, Joseph Henry articulated a program that included the following statement:

"It is proposed to publish a series of reports, giving an account of the new discoveries

in science, and of the changes made from year to year in all branches of knowledge

not strictly professional." This keynote of basic research has been adhered to over the

years in the issuance of thousands of titles in serial publications under the Smithsonian

imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing

with the following active series:

Smithsonian Annals of Flight

Smithsonian Contributions to Anthropology

Smithsonian Contributions to Astrophysics

Smithsonian Contributions to Botany

Smithsonian Contributions to the Earth Sciences

Smithsonian Contributions to Paleobiology

Smithsonian Contributions to ^oology

Smithsonian Studies in History and Technology

In these series, the Institution publishes original articles and monographs dealing

with the research and collections of its several museums and offices and of professional

colleagues at other institutions of learning. These papers report newly acquired facts,

synoptic interpretations of data, or original theory in specialized fields. Each publication is distributed by mailing lists to libraries, laboratories, institutes, and interested

specialists throughout the world. Individual copies may be obtained from the Smithsonian Institution Press as long as stocks are available.

S. DILLON RIPLEY

Secretary

Smithsonian Institution
SMITHSONIAN CONTRIBUTIONS TO

ZOOLOGY

NUMBER 40

Thomas Pheian A Field Guide to the

Gidaroid Echinoids

of the Northwestern

Atlantic Ocean,

Gulf of Mexico, and

the Caribbean Sea

SMITHSONIAN INSTITUTION PRESS

CITY OF WASHINGTON

1970
ABSTRACT

Phelan, Thomas. A Field Guide to the Cidaroid Echinoids of the Northwestern

Atlantic Ocean, Gulf of Mexico, and the Caribbean Sea. Smithsonian Contributions to

Zoology, 40:1-67. 1970.—Twelve species of cidaroid echinoids from the northwestern

Atlantic Ocean, Gulf of Mexico, and the Caribbean Sea are described, compared,

illustrated, and keyed for identification. The first description of the denuded test of

Histocidaris nuttingi Mortensen is presented. A lectotype and paralectotype are selected

for Histocidaris sharreri (A. Agassiz). Poriocidaris purpurata (Wyville Thompson),

previously known from the eastern Atlantic, is reported for the first time from the

Caribbean Sea.

Official publication date is handstamped in a limited number of initial copies and is recorded

in the Institution's annual report, Smithsonian Year.

UNITED STATES GOVERNMENT PRINTING OFFICE

WASHINGTON : 1969

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

Washington, D.C. 20402 - Price $1.25 (paper cover)
Thomas Phelan A Field Guide to the

Cidaroid Echinoids

of the Northwestern

Atlantic Ocean,

Gulf of Mexico, and

the Caribbean Sea

Introduction

The quest for knowledge of the sea and the study of

marine organisms have been attracting an ever increasing number of biologists, students, and serious

hobbyists. The primary interest may not be systematics, but the identity of specimens often is essential

to other works. Identification is frequently hampered

by lack of readily available literature. Indeed, many

of the descriptions are scattered through out-of-print

publications. This paper is the first of a series to provide researchers who are not echinoid specialists with

a field guide to the species of echinoids known to

inhabit the northwestern Atlantic Ocean, Gulf of

Mexico, and the Caribbean Sea. Twelve species of

cidaroid echinoids are compared and keyed for

identification.

The differences between some of these species are

not as distinct as suggested in the literature. Therefore,

in addition to presenting a key for identification, the

variations in form that cause difficulty in identification are discussed. This study is based on material

in the United States National Museum (USNM) and

the Museum of Comparative Zoology (MCZ),

Harvard.

Thomas Phelan, Division of Invertebrate Paleontology,

Smithsonian Institution, Washington, D.C. 20560

Acknowledgments

The author thanks Dr. David Pawson and Miss

Maureen E. Downey of the Division of Echinoderms,

United States National Museum for the use of specimens and a friendly exchange of ideas; Professor

Barraclough Fell, Museum of Comparative Zoology,

Harvard, for the loan of specimens. I am sincerely

grateful to Dr. Porter M. Kier for valuable advice

and encouragement all of which were generously given.

Diagnostic Features of Cidaroid Echinoids

Echinoids are of many forms, each representing adaptation to a particular niche in the marine environment. Some echinoids are almost entirely radially symmetrical; others have strong bilateral features yet retain some radial symmetry. Echinoids with the mouth

and anus at opposite poles of a vertical axis and almost

exclusively radially symmetrical are commonly called

sea urchins or regular echinoids. The cidaroids are sea

urchins with distinctive features that readily set them

apart from other kinds.

The more or less globular main portion of the skeleton termed the test or corona is composed of twenty

vertical columns of calcareous plates. In the cidaroids

and most other sea urchins these plates are rigidly

joined together. The vertical columns of plates are

arranged in similar pairs to form ten distinct sections.
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Five sections of the test consist of perforate plates.

These alternate with five sections composed of imperforate plates (Plate 1: figure 7; Plate 2: figures 1, 2).

Two columns of perforate plates form one ambulacrum. In the cidaroids each ambulacral plate bears

one pair of pores to accommodate a tube foot. The

pores are arranged in a single vertical sinuate series

(Plate 2: figures 1, 2). The single series of pore pairs

and simple plates are not restricted to the cidaroids.

Other sea urchins commonly have simple plates, but

many noncidaroids have compound plates with several

pore pairs per plate. The pore pairs of noncidaroids

are arranged in single series, multiple series, or in a

series of arcs. Toward the ambulacral midline adjacent

to each pore pair there is a marginal tubercle on the

cidaroid echinoids that also forms a vertical series

(Plate 2: figure 6), small inner tubercles are scattered

or arranged in series between the two series of marginal tubercles. There are no large primary tubercles

with accompanying large primary spines in the

ambulacra.

Each of the five sections consisting of two vertical

columns of imperforate plates is termed an interambulacrum. Interambulacral plates of cidaroid echinoids

have one large primary tubercle per plate which is

crenulate (Plate 11: figures 1, 3) or noncrenulate

(Plate 17: figure 5). This tubercle commonly bears a

large primary spine. The largest spines are at or just

above the equator or ambitus of the test (Plate 4: figure 6; Plate 9: figure 2). Noncidaroid echinoids

bear one or more large primary spines per interambulacral plate. A large, smooth, somewhat circular area

devoid of surface ornamentation is present in the region

around each primary tubercle. This consists of the boss

or expanded base of the primary tubercle and the surrounding somewhat depressed ring or areole, which

serves for primary spine muscle attachment (Plate 2:

figure 1). Beyond the areole the plate is covered with

small secondary tubercles. Those bordering the areole

are slightly larger than the others, commonly forming a

distinct scrobicular ring (Plate 6: figures 3, 4). The

tubercles of the scrobicular ring carry scrobicular

spines, specialized secondary spines (Plate 5: figure 6).

Among the noncidaroids only the salenioid echinoids

have a similar interambulacral plate. The salenioids

are distinguished by other features of the test which are

discussed in the following paragraphs.

At the apex of the test is a complex of plates called

the apical system (Plate 2: figures 4, 8). There are five

ocular plates, one situated at the adapical end of each

ambulacrum. Each ocular plate bears an ocular or

terminal pore. Five additional plates each with a genital pore are situated at the adapical ends of the interambulacra. The genital plates are larger than the oculars, and the genital pore is also larger than the terminal

pore. One of the genital plates has a porous sievelike

area, the madreporite, commonly slightly larger than

the other genital plates. These ten plates are collectively termed the oculogenital ring.

The oculogenital ring surrounds a flexible membrane, the periproct, in which the anus is located.

Periproct outline and plate arrangement are important

diagnostic features. The periproct of a cidaroid echinoid is always pentagonal and bears plates decreasing

in size toward the centrally located anus (Plate 2:

figures 4, 8). This is a distinct feature of the cidaroids.

The salenioids that most closely resemble the cidaroids have the anal opening off-center due to the presence of a large suranal plate absent in the cidaroids.

There is a large opening on the underside or adoral side of the denuded test. Prior to the loss of tissue

this opening is covered with plates and a flexible

membrane, the peristome (Plate 1: figures 7, 8; Plate

11: figure 2), with the mouth located in the center.

In cidaroid echinoids imbricating ambulacral plates,

B

FIGURE 1.—The top of the junction of pyramid halves (A) is

higher than the lowest part of the epiphyses (B) in a cidaroid

lantern. The reverse is true in noncidaroid lanterns. See

PLATE 1: figures 2, 3.
NUMBER 40

and to some extent interambulacral plates, extend

across the peristome to the mouth (Plate 1: figure 7).

Interambulacral plates bordering the peristome of

cidaroids internally bear apophyses (Plate 1: figure

5), the main supports for the masticating device commonly called the Aristotle's lantern or simply the lantern (Plate 1: figure 2). Noncidaroid sea urchins have

as the main lantern supports auricles that are internal

projections from the ambulacral plates (Plate 1: figure

6).

The cidaroid lantern contains five jaws, termed pyramids, each with an unkeeled tooth (Plate 1: figure 1).

A keel is a projection on the inner surface of the

tooth that extends throughout the length of the hard

portion (Plate 1: figure 4). Noncidaroids have unkeeled or keeled teeth.

Each pyramid (Figure 1; Plate 1: figure 2) consists

of two demipyramids which join along the dental

slide. The junction surface is called the symphysis.

A notch on each side of the top of a pyramid accommodates a lantern member termed an epiphysis. In

cidaroid echinoids the uppermost part of the junction of pyramid halves (Figure 1A), symphysis, is

higher than the upper limit of the lateral wings at

the junction with the epiphyses (Figure 1B). The reverse is true on noncidaroid sea urchins (Plate 1:

figure 3).

Cidaroids have no gills, but all other rigid-test sea

urchins including the salenioids have gills accompanied by a notch in each basicoronal interambulacral

plate. The notch opens toward the peristome. Gill

notches may be deep, as on Tripneustes ventricosus

(Lamarck) (Plate 1: figure 8), or very shallow, as in

Arbacia punctulata (Lamarck). The absence of gill

notches is a diagnostic feature of the cidaroids (Plate

1: figure 7).

A list of significant cidaroid and noncidaroid characters is provided for quick reference. Some of the

cidaroid features listed are not restricted to cidaroids;

Those restricted to cidaroids are in boldface type.

Only a few significant noncidaroid characters are

presented.

list of Significant Characters

Test:

(General)

Ambulacra:

Cidaroid

Rigid, regular sea urchin form

(periproct within apical system)

lacking gill notches

Plates simple

Pore pairs in single series

Sinuate to some extent

Marginal tubercle adjacent to

each pore pair

Noncidaroid

Interambulacra:

Apical System:

Peristome:

Teeth:

Pyramids:

One primary tubercle and spine

per plate

Primary tubercles perforate

Apophyses are the prominent

lantern supports

Periproct pentagonal

Covered with a regular series of

imbricating plates in the ambulacra, and to some extent in the

interambulacra

Unkeeled

Upper limit of symphysis is

higher than the top of the lateral

wings at the junction with the

epiphyses

Rigid, regular sea urchin form

(periproct within apical system)

with gill notches

Flexible, regular sea urchin form

Rigid, irregular echinoid form

(periproct outside apical system)

Plates compound

Pore pairs in multiple series, or in

a series of arcs

Large primary tubercles and

spines

Auricles are the prominent lantern

supports

More than one primary tubercle

and spine per plate

Primary tubercles imperforate

Suranal plate

One pair of perforate plates in line

with each ambulacrum

Keeled

The top of the lateral wings at the

junction with the epiphyses is

higher than the upper limit of the

symphysis
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

The Diagnostic Value of Gidaroid Pedicellariae

Pedicellariae, small pincerlike organs, defend the echinoid from small organisms, especially pelagic larvae

seeking a place for attachment The pedicellariae are

scattered all over the test among the spines (Plate 8:

figure 8). Most pedicellariae consist of three jawlike

valves at the distal end of a flexible stalk which contains

a calcareous supporting rod. Pedicellariae with valves

containing venomous glands are termed globiferous

pedicellariae (Figures 2-6; Plate 19: figures 6, 7) and

are recognized by the presence of a chamber within

each valve to accommodate the venom gland. This

chamber has an opening (Figure 2B) at the distal end

of the valve blade. The relative size of the blade opening, its position, and tooth configuration are diagnostically important.

The term tridentate is applied to nonvenomous pedicellariae commonly with three relatively long-bladed

valves (Figure 7; Plate 15: figure 1). One species

discussed in this paper has only two valves in each of

its tridentate pedicellariae (Plate 10: figure 2). Only

the large globiferous (Figures 2-6) and large tridentate pedicellariae (Figure 7) are used in this work as

aids in identification.

FIGURE 3.—The large globiferous pedicellariae of Tretocidaris

have a large single end tooth and a very small blade opening.

A short closed space is between the blade opening and the

end tooth.

FIGURE 2.—The large globiferous pedicellariae of Cidaris and

Calocidaris have a large single end tooth (A) and a large

blade opening (B). A short closed space is between the blade

opening and end tooth.

FIGURE 4.—The large globiferous pedicellariae of Eucidaris

and Stylocidaris lack a large single end tooth at the tips of the

blades. The blade opening is terminal.
NUMBER 40

FIGURE 5.—The large globiferous pedicellariae of Stereocidaris lack a large single end tooth at the tips of the blades.

The blade opening is subterminal. See Figure 6.

FIGURE 6.—The two uppermost teeth of the blade opening

are commonly larger than the other teeth surrounding the

blade opening on the large globiferous pedicellariae of

stereocidaris. These two larger teeth commonly coalesce giving the illusion of a single end tooth, but there is no closed

space between these teeth and the blade opening as in

Cidaris and Calocidaris.

FIGURE 7.—A three-valve tridentate pedicellaria. The blade

(A) is the slender upper portion of each valve. The valves

lack the venom chambers present in globiferous pedicellariae.

The valves of a pedicellaria are attached to a calcareous supporting rod (B).

B
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Diagnostic features of Cidaroid Pedicellariae

No globiferous

pedicellariae

Histocidaris

Poriocidaris

Large globiferous pedicellariae have

a single large end tooth, closed

space between end tooth and blade

opening

Blade opening

large, Figure 2

Cidaris

Calocidaris

Blade opening

very small,

Figure 3

Trelocidaris

No large single end tooth

Blade opening

terminal, Figure 4

Stylocidaris

Eucidaris

Blade opening

subterminal,

Figures 5, 6

Stereocidaris

Diagnostic features of the large tridentate pedicellariae on the histocidarids

Valves very

large and broad,

Plate 12:

figure 5

H. sharreri

Valves very

large, long, and

slender, Plate 15:

figure 1

H. nuttingi

All pedicellariae composed of two

highly compressed valves, Plate 10:

figure 2

Poriocidaris purpurata

Techniques

The large globiferous pedicellariae of Cidaris and

Calocidaris are best studied with the valves separated

and the tissue removed. This is easily accomplished

using a solution of 10 parts water to 1 part household

bleach, and the process takes approximately 15 minutes

to complete. The valves should then be rinsed in water.

The calcite lattice structure of an echinoid is translucent and therefore does not photograph well in reflected light. In order to overcome this problem, the

dry specimens were coated with red ink, but alizarin

crimson watercolor or any low-sediment dye can be

used. After the ink dried thoroughly, the specimen was

lightly coated with ammonium chloride from a "smoke

generator" (Teichert, 1948, p. 102). In Plate 1: figure

8, only the area around the edge of the peristome was

treated. Notice how vividly the gill slits stand out in

the photograph compared to the tubercles in the lower

right-hand corner.

Key to the Cidaroid Echinoids of the Northwestern Atlantic Ocean,

Gulf of Mexico, and the Caribbean Sea

la. Tubercles strongly crenulate, crenulation on some or most tubercles even below the ambitus;

peristomial ambulacra! plates with an internal prolongation (Plate 10: figure 3); globiferous pedicellariae lacking; oral primary spines very strongly serrate, distinctly curving

toward mouth Histocidaris, Poriocidaris 2

b. Not as above 3

2a. All pedicellaria bivalve (Plate 10: figure 2), oral primaries with blunt rounded tips (Plate 11:

figure 6). Primary spines white, uppermost primaries of some specimens have a long brown

or purple collar, spines cylindrical or gently tapering. Secondary spines brown or purplish

brown; ambulacral inner tubercles sparse (Plate 12: figures 6, 7); few interambulacral

secondary tubercles (Plate 11: figure 3) Poriocidaris purpurata (Wyville Thomson)
NUMBER 40

Key to the Cidaroid Echinoids of the Northwestern Atlantic Ocean,

Gulf of Mexico, and the Caribbean Sea—Continued

b. Oral primary spines have a slender tip (Plate 15: figure 6); large tridentate pedicellariae

with long slender blades (Plate 15: figure 1); all spines white or nearly so; test commonly

white; marginal tubercles of two sizes; larger form distributed in a zigzag pattern with

accompanying larger marginal spines (Plate 14: figure 5); ambulacral midzone with an

abundance of inner tubercles Histocidaris nutlingi Mortensen

c. Oral primaries rather short with blunt broadly rounded tips (as in P. purpurata, Plate 11:

figure 6); primary spines white, secondaries brown (Plate 13: figures 1-3); tridentate

pedicellariae with large broad valves (Plate 12: figure 5); ambulacrum with very few

inner tubercles (Plate 12: figures 8, 9, 11); interambulacral plate with few secondary

tubercles (Plate 14: figures 1, 2) Histocidaris sharreri (A. Agassiz)

3a. Large globiferous pedicellariae with distinct end tooth (Figures 2, 3) 4

b. Large globiferous pedicellariae without the single end tooth (Figures 4-6) 6

4a. Blades of large globiferous pedicellariae with large opening (Figure 2); areoles usually

large, deep; upper tubercles of some specimens weakly crenulate 5

b. Blades of large globiferous pedicellariae with very small opening (Figure 3); areoles shallow,

upper side of upper tubercles strongly crenulate (Plate 21: figure 4); primary spine with

light and dark bands, spinules larger on upper than underside of primary spines (Plate 21:

figures 5-7; Plate 22: figures 1, 2) Tretocidaris bartletti (A. Agassiz)

5a. Test relatively globular interambulacral midzone slightly sunken (Plate 2: figures 2, 8);

extrascrobicular tubercles of upper interambulacral plates in horizontal rows separated

by furrows (Plate 2: figures 1, 2); primary spines very long smooth (lacking spinules)

and shiny (Plate 2: figures 3, 5; Plate 3: figures 1, 4, 7); scrobicular (Plate 2: figure 7)

and marginal spines slender, long, with pointed tips Calocidaris tnicans (Mortensen)

b. Test commonly flattened above (Plate 4: figure 6); many uppermost tubercles rudimentary

(Plate 5: figures 1, 2); scrobicular ring of tubercles inconspicuous, extrascrobicular

tubercles of upper interambulacral plates in horizontal rows separated by furrows (Plate 5:

figures 1, 2); primary spines fairly smooth not shiny, usually white, cylindrical or tapering,

spinules noticeable on adoral primary spines but commonly reduced or lacking on those

of the ambitus and above, large primary spines directed out horizontally, tip commonly

slightly flaring to form a small hollow "hoof (Plate 4: figure 1)

Cidaris abyssicola (A. Agassiz)

c. Test slightly flattened above; few rudimentary tubercles, areoles very large; extrascrobicular

area very limited, secondary tubercles very small (Plate 6: figure 3); primary spines with

well-developed spinules, those above the ambitus commonly flared to paddle shape (Plate 8:

figures 1,2); oral primaries commonly with moderate serration

Cidaris blakei (A. Agassiz)

d. Test slightly flattened above, few rudimentary tubercles, areoles large, extrascrobicular area

with fairly large secondary tubercles (Plate 6: figure 4); sutures not naked; primary

spines (Plate 10: figure 1) 2 to 2.5 times the horizontal diameter of the test, commonly

swollen beyond the short collar (Plate 8: figure 7), tapering to the tip, rows of spinules

well developed; a few of the largest spines on some specimens have a flat widening of

the tip (Plate 8: figure 6), oral primary serration slight to lacking

Cidaris rugosa (H. L. Clark)

6a. Test low flattened, very few rudimentary tubercles; ambulacra midline and all interambulacral

sutures very naked; 5 to 7 interambulacral plates per row; primary spines 1.5 to 2 times

the horizontal diameter of the test, round slender, only very gently tapering toward the

tip, almost cylindrical, many directed upward but not vertically; moderately developed

rows of spinules 7

b. Test low, adapically flattened (Plate 22: figure 5); midline of ambulacra not naked; interambulacra with 5 to 7 plates in a row, interambulacral transverse sutures not naked,

interambulacral midline sutures with only a slight trace of nakedness; primary spines

1.5 to 2 times the horizontal diameter of the test, directed out horizontally, well-developed

rows of spinules, uppermost row commonly forming a conspicuous crest (Plate 22:

figures 8, 9) Stereocidaris ingolfuma Mortensen

359-863—69-
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Key to the Gidaroid Echinoids of the Northwestern Atlantic Ocean,

Gulf of Mexico, and the Caribbean Sea—Continued

c. Test commonly flattened adapically; ambulacra! midline not naked; interambulacra with

9 to 12 plates per column, areoles rather small, shallow (Plate 17: figure 5), interambulacral sutures not naked; primary spines stout, short, slightly longer than the horizontal diameter of the test, but may be less, primary spine spinules are wartlike, a dense

covering of hair commonly hides the spine shaft, crownlike tip (Plate 16: figures 2-4;

Plate 17: figures 1-3). Scrobicular spines with very broad blunt tip (Plate 16: figure 1).

Eucidaris tribuloides (Lamarck)

7a. Round granules scattered rather uniformly on all apical system plates (Plate 19: figure 1);

ambulacral midline and all interambulacral sutures very naked and white (Plate 19:

figure 3; Plate 18: figure 6); scrobicular and marginal spines with reddish midline stripe

(Plate 19: figure 3); primary spines on some specimens banded (Plate 18: figure 6;

Plate 20: figure 4) Stylocidaris affinis (Philippi)

b. Naked reddish-brown ring in apical system, granules elongate, directed away from both

sides of the reddish-brown ring (Plate 19: figures 2, 5); ambulacral midline and all interambulacral sutures very naked and reddish-brown (Plate 19: figure 4); scrobicular spines

white without midline stripe (Plate 19: figure 4) Stylocidaris lineata Mortenscn

Distribution

Only a general listing of distribution is provided because collecting has been insufficient and reports havebeen hampered by inaccuracies due to misidentification of specimens.

Species

Calocidaris micans

Cidaris abyssicola

Cidaris blakei

Cidaris rugosa

Eucidaris tribuloides

Histoddaris nuttingi

Histocidaris sharreri

Porioeidaris purpurata

Stereocidaris ingolfiana

Stylocidaris affinis

Stylocidaris lineata

Tretocidaris bartletti

Distribution

West Indies, Gulf of Mexico

Cape God to Florida and West Indies

Cuba to Barbados

32°N off U.S. east coast, south through West

Indies

Throughout the West Indies, Gulf of Mexico,

and Bermuda

Cuba to Antigua

Leeward Islands

South of Ireland to the Canary Islands and

Caribbean Sea

North Atlantic Denmark Strait to Cape Verdes

and the Caribbean Sea

Bermuda, West Indies, Caribbean Sea, and Gulf

of Mexico, eastern Atlantic and the Mediterranean Sea

West Indies

West Indies, Caribbean

Depth in meters

200-330

200-400

315-420

130-540

littoral to 450

320-415

?—570—?

750-1800

300-1750

30-1000

100-500

140-625

Calocidaris micans (Mortensen)

PLATE 2: FIGURES 1-8; PLATE 3: FIGURES 1-7

Calocidaris micans.—For a complete synonymy see Mortensen, 1928, p. 312; for an additional description see Mortensen, 1910, p. 2.

The test of Calocidaris micans is relatively high, up to

0.75 of the horizontal diameter of the test. It is generally globular in appearance when viewed from the

side; the test is not flattened above or below (Plate 2:

figure 2). The peristome and apical system maintain

the regular curving of the sides. The basicoronal plates

are not incurving at the edge of the peristome.

The ambulacral interporiferous zone in the ambital

region contains four series of almost equal-size tubercles; an inner tubercle and a slightly larger marginal

tubercle on each plate (Plate 3: figure 6). On complete specimens the ambulacral midline is only scarcely

naked.

The interambulucral midzone is sunken as there is
NUMBER 40

a sloping of the extxascrobicular area from the areole

to the midline suture. Extrascrobicular tubercles are

arranged in almost horizontal rows separated by

distinct furrows. Areoles are large, the scrobicular ring

reaching the upper and lower edges of all but the uppermost plates. Areole confluence is generally limited

to the two lower plates of each column. On some

specimens the upper side of the upper tubercules and

spines are slightly crenulate (Plate 2: figures 1,5). The

scrobicular ring is somewhat inconspicuous, because

the scrobicular tubercles are only slightly larger than

the adjacent extrascrobicular tubercles.

The primary spines are without doubt the most

diagnostic feature of C. micans. They are almost

cylindrical, gently tapering at the tip, smooth and

shiny, completely lacking hairs and spinules. Primary

spines above the ambitus have approximately 16 narrow glassy zones running the length of the shaft. These

are so slightly elevated above the rest of the spine

that they are not noticeable to the unaided eye. Below

the ambitus these glassy zones form inconspicuous

glassy ridges completely lacking spinules. All other

cidaroids develop rather conspicuous spinules on the

primary spines below the ambitus; even those that have

rather smooth spines above the ambitus. The most

spectacular specimens of C. micans have primary spines

up to three times the horizontal diameter of the test

(Plate 3: figures 1, 7), but on others they are commonly one and a half times the horizontal diameter of

the test. The primary spines are almost white, but there

is a reddish-brown pigment in the collar, slight olive

color in the neck and shaft, and a trace of reddish

brown toward the tip. Specimens give the overall appearance of being white, but close observation reveals

a slight olive tint.

COMPARISON WITH OTHER SPECIES.—Indentification

difficulties would most likely be limited to differentiation between C. micans and some specimens of Cidaris

abyssicola. Cidaris abyssicola is noticeably flattened

adapically and somewhat adorally as there is a slight

incurving of the test at the edge of the peristome.

The primary spines are fusiform or cylindrical, white,

somewhat chalky in appearance. Spinules are commonly small, even lacking on some spines. The primary

spines of some specimens are very smooth and somewhat shiny. The various kinds of spines may be present

on a single specimen. Below the ambitus of C. abyssicola the primary spines develop rows of spinules even

on specimens with smooth shiny upper spines. This

contrasts with C. micans which lacks spinules even on

primary spines below the ambitus. Spines below the

ambitus on C. micans bear low smooth glassy ridges

that extend the length of the shaft.

The form of C. abyssicola that Mortensen (1910,

p. 13) described as C. abyssicola var. teretispina (Plate

5: figure 3) has slender, usually cylindrical, smooth,

and quite shiny primary spines and a faint olive pigment. The primary spines at and above the ambitus are

therefore quite indistinguishable from those of the

shorter spine specimens of C. micans. Below the ambitus the primary spines bear spinules as on other specimens of C. abyssicola. The scrobicular and secondary

spines are very similar to the slender pointed ones of

C. micans. The slender smooth spine specimens of C.

abyssicola commonly have some primary spines

terminating with a "hollow-hoof tip similar to those

found on some spines of the more typical specimens

(Plate 4: figure 1).

I have not observed Mortensen's variety C. abyssicola teretispina with a globular test similar to that of

C. micans. The more typical C. abyssicola with stouter

white spines has been observed with a rather globular

test and elevated apical system (Plate 5: figure 2).

Rudimentary tubercles occur on fairly large interambulacral plates on C. abyssicola (Plate 5: figure 1),

but they are apparently limited to smaller plates on C.

micans (Plate 2: figure 8).

DISTRIBUTION.—West Indies and Gulf of Mexico at

depths of 200-330 meters.

Cidaris abyssicola (A. Agassiz)

PLATE 1: FIGURE 7; PLATE 4: FIGURES 1-6; PLATE 5:

FIGURES 1- 6

Cidaris abyssicola—For a complete synonymy see Mortensen,

1928, p. 301; for additional descriptions see Mortensen,

1910, p. 13, and 1928, p. 301.

The test of Cidaris abyssicola is commonly rather low

with a flattened apical system and peristome (Plate 4:

figure 6). The basicoronal plates are slightly incurving

at the edge of the peristome. At the ambitus the periphery is circular with no sunken area in the interambulacra. The flattened test is not a reliable diagnostic feature as some specimens are quite globular with

elevated apical system (Plate 5: figure 2) and gently

curving sides instead of the strongly arched condition

found in the more flattened specimens.

The ambulacra are slightly sinuate, and the marginal
10

tubercles are in regular series. The inner tubercles are

variously arranged on different specimens. There may

be one small inner tubercle below center on each

ambulacral plate or as many as three inner tubercles

are common. The arrangement with three inner tubercles is generally one above the other adjacent to the

marginal tubercle and the third below the center of

the plate near the midline suture. The lower edge of

the plate commonly bears several small granules. The

inner tubercles tend to form in uniform series, but in

some specimens they are rather irregularly arranged.

Specimens with inner tubercles in regular series high

on the test may have them in a jumble near the peristome (Plate 5: figures 4,5). The arrangement of inner

tubercles is not a diagnostic one for this species. It is

more significant that the interporiferous zone is rather

crowded with tubercles, while not obscuring the midline as in Stereocidaris ingolfiana.

The upper plates of the interambulacra of most

specimens are slightly higher than wide and many

bear rudimentary primary tubercles (Plate 5: figure

1). The areoles are moderately large and the scrobicular rings reach the upper and lower edges of the

plates everywhere below the ambitus. The areoles are

confluent in the two or three lowermost plates of a

column. Extrascrobicular tubercles are in more or less

horizontal rows separated by furrows and in much

greater abundance above than below the ambitus.

The primary spines are directed out horizontally as

spokes around the hub of a cartwheel (Plate 4: figure

6). The large primary spines are commonly rather

smooth, spinules are small or lacking. These spines

are generally white, even chalky in appearance and

from 1 to 1.5 times the horizontal diameter of the

test, cylindrical or fusiform. A "hollow hoof is common on spines with unbroken tips (Plate 4: figure 1).

Below the ambitus the primary spines develop more

prominent spinules.

The test and spines are generally white, but touches

of pink and olive are common. The collar of the primary spines is generally the darkest portion of the

specimen. Scrobicular spines of some specimens have

a slight olive midline, but not a stripe or as distinct as

the red midline stripe of Stylocidaris affinis.

COMPARISON WITH OTHER SPECIES.—Cidaris abyssicola is rather distinct and should not be difficult to

identify, but since some specimens bear superficial resemblance to Calocidaris micans a comparison is necessary. A more detailed comparison is given under

Calocidaris micans. The large primary spines of C.

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

micans are very smooth and shiny. Most specimens of

Cidaris abyssicola have fairly smooth but not shiny

large primary spines, but there are some specimens of

C. abyssicola that have more slender rather shiny spines

with a slight olive tint. These specimens of C. abyssicola can be distinguished from specimens of C. micans

by examination of the primary spines below the ambitus with a hand lens. Spinules can be observed on

these spines of C. abyssicola, but only longitudinal

glassy ridges are present on the primary spines below

the ambitus on C. micans. The oral primary spines of

C. abyssicola generally have distinctly serrate edges.

The oral primaries of C. micans lack serrations but

have well-developed longitudinal ridges and thin edges

(Plate 3: figure 3). The midzones of the interambulacra of C. micans are sunken. They are not sunken on

C. abyssicola.

DISTRIBUTION.—East coast of the United States

south of Cape Cod, including Florida, and the West

Indies at depths of 200 to 400 meters.

Cidaris blakei (A. Agassiz)

PLATE 6: FIGURES 1, 3, 5; PLATE 7: FIGURES I, 6-8; PLATE

8: FIGURES 1-5, 8; PLATE 9: FIGURES 1, 2

Cidaris blakei.—For a complete synonymy see Mortensen,

1928, p. 307; for additional descriptions see A. Agassiz,

1883, p. 10, and Mortensen, 1928, p. 307.

The test of Cidaris blakei is moderately to slightly flattened above and below (Plate 7: figure 1), and its

height is approximately two-thirds the horizontal diameter. The test is round at the ambitus, the interambulacral midzones are not sunken. There is a slight

incurving of the basicoronal plates at the edge of the

peristome.

The ambulacra are distinctly sinuate above the ambitus, less sinuate below. This is apparently due to the

very large areoles on the interambulacral plates above

the ambitus. The pore pairs are slightly oblique and

the ambulacral marginal tubercles are high on each

plate, tending to crowd above the inner edge of the inner pore that is low on the plate. Small granules are

common on the lower edge of the plates below the

marginal tubercles which are in uniform series. Adjacent to the marginal tubercle is an inner tubercle

low on the plate. This inner tubercle and the marginal

tubercle lie in an oblique position very nearly parallel

to the oblique position of the pore pair of the same

plate. If an additional inner tubercle is present on the
NUMBER 40

11

plate, its position is commonly at random but crowding the midline edge of the plate. Although I have

not observed it, Mortensen (1928, p. 307) reported

the additional inner tubercles as being in a uniform

series. The inner tubercles adjacent to the marginal

tubercles are in a uniform series.

The areoles are large and occupy a major portion

of the interambulacral plates. Above the ambitus the

areoles are very large and only very newly introduced

plates have rudimentary tubercles. The areoles of the

two or three lowermost plates are commonly confluent. Crenulation is not diagnostic but is weakly

present in the uppermost tubercles of some specimens.

The scrobicular ring of tubercles is very distinct. These

tubercles are considerably larger than the almost

granular secondary tubercles (Plate 6: figure 3).

The uppermost primary spines of some specimens

resemble the fan-shaped leaves of the ginkgo tree

(Plate 8: figures 1, 2; Plate 9: figure 2). On such

specimens the great widening of the spine tip is

progressively decreased with descending position of the

spines toward the adoral side. Spines below the ambitus are quite slender and lack the widened tip. The

variation among specimens is remarkable and ranges

from those as shown in Plate 8 to specimens possessing

only slender-pointed tipped spines. Indeed, specimens

with little or no widening of the spine tip are common.

Some slender spines bear a very small flared tip, like a

funnel cone. The spinules are easily visible but not

thorny. The oral primary spines are rather distinctly

serrate. The secondary spines are small, slender, and

almost pointed, and contrast with the broader more

bluntly tipped scrobicular spines.

The slender, only slightly flattened, almost pointed

marginal spines of the ambulacra, slender extrascrobicular spines, and the almost granular size of the

extrascrobicular tubercles are very diagnostic and are

the most significant features of specimens lacking the

fan-shaped spines. The very large areoles are important features also, but C. rugosa has large areoles and

resembles some specimens of C. blakei.

The color was reported by A. Agassiz (1883, p. 12)

as being brilliant vermilion. Most of the color has been

lost from specimens stored in alcohol or dried. The

spines may have been white, for they show no trace of

color in the shaft.

COMPARISON WITH OTHER SPECIES.—Cidaris blakei

and Cidaris rugosa have been collected together at

several localities and can be easily identified when they

bear their highly characteristic spines (Plate 8: figures

1, 2, 7), but some specimens of these species have only

slender primary spines similar to those of Stylocidaris

affinis (Plate 20: figure 4). Specimens that lack the

distinctive spines may be identified by examining the

extrascrobicular area of the interambulacral plates,

the granular tubercles of the apical system, and the tips

of the marginal spines. The extrascrobicular area of C.

blakei occupies a smaller percentage of the plate and

is covered with more delicate secondary tubercles than

on C. rugosa (Plate 6: figures 3, 4). The granular

tubercles of the apical system of C. blakei are also

smaller and less prominent than those of C. rugosa

(Plate 6: figures 5,6).

The inner tubercles of the ambulacra are commonly

in more uniform series in C. blakei. On specimens of

C. rugosa with a single inner tubercle on each ambulacral plate a partial vertical overlap of tubercles occurs

and a single zigzag series is formed along the midline

(Plate 7: figure 4). Large specimens of C. rugosa commonly have inner tubercles of the ambulacra one above

the other adjacent to the marginal tubercles of a single

plate (Plate 7: figure 9). This condition may exist on

a majority of the plates with additional inner tubercles

toward the midline. These specimens tend to show a

uniform series of inner tubercles. The inner tubercle

arrangement is variable and therefore of little help in

identification.

The marginal spines of C. rugosa are noticeably

broader and more bluntly tipped than those of C.

blakei (Plate8: figures 8,9).

DISTRIBUTION.—Cuba to Barbados in the West Indies at depths of 315 to 420 meters.

Cidaris rugosa (H. L. Clark)

PLATE 6: FIGURES 2, 4, 6; PLATE 7: FIGURES 2-5, 9; PLATB

8: FIGURES 6, 7, 9; PLATE 10: FIGURE 1

Cidaris rugosa.—For a complete synonymy see Mortensen,

1928, p. 305; for additional description see H. L. Clark,

1907, p. 210.

The test of Cidaris rugosa is moderately to slightly flattened above and below (Plate 7: figure 2). Height

of the test is approximately two-thirds the horizontal

diameter. Only rarely are the basicoronal plates incurving at the edge of the peristome. The test is round at

the ambitus with no sunken interambulacral midzone.

The ambulacra are moderately sinuate; only slightly

more noticeably so above than below the ambitus. Pore

pairs are in a slightly oblique position on the plates and
12

the marginal tubercles are higher than center, but the

tubercles only tend to crowd above the inner pores

adorally. The marginal tubercles form a uniform series

and bear fairly broad, noticeably flattened, bluntly

tipped spines (Plate 8: figure 9). Small granules are

common below the marginal tubercles. There is no

naked area in the midzone between the rows of marginal tubercles. When only one inner tubercle is present

on each ambulacral plate, it occupies most of the area

between the marginal tubercle and the midline suture.

The appearance of crowding is evident. In the above

condition the inner tubercles partially overlap each

other along the midline suture forming a single zigzag

series (Plate 7: figure 4). On larger specimens additional inner tubercles are present. Adjacent to the marginal tubercle there are commonly two inner tubercles,

one above the other (Plate 7: figure 9). These tend

to form into a uniform series. An additional inner

tubercle is commonly present on the plate crowding

the midline and the vertical pair of inner tubercles.

This arrangement on C. rugosa gives the appearance

of a more uniform series of inner tubercles than on

those with a single inner tubercle in a zigzag series. The

lack of any naked area in the midzone is the most

significant feature of the interporiferous zone. The

variability of inner tubercle arrangement exempts their

number and position from being a good diagnostic

feature.

Each interambulacral plate has a large areole which

occupies a major portion of the plate. Rudimentary

tubercles are limited to newly introduced plates. The

scrobicular rings are prominent and extend to the

upper and lower edges of the plates except on the

uppermost plates of the test The two lowermost plates

commonly have confluent areoles. The extrascrobicular tubercles are prominent, standing out on the

plate as rugged little knobs. This feature markedly distinguishes the interambulacral plates of C. rugosa from

those of C. blakei (Plate 6: figures 3, 4). The small

granular tubercles of the apical system are also prominent (Plate 6: figure 6).

Primary spines of the more typical specimens are

from 2 to 2.5 times the horizontal diameter of the

test; markedly swollen just above the collar, round,

and tapered to the tip. The spinules are prominent

but not thorny (Plate 8: figure 7). The swollen area

above the collar is absent on some specimens, and the

spines then have a more slender appearance. Some of

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

the longer spines on some specimens have a flattened

slightly expanded tip resembling the less expanded

spines of C. blakei (Plate 8: figure 6). The oral primaries vary from nonserrated to moderately serrated.

The marginal, scrobicular, and extrascrobicular spines

are flattened, rather broad and blunt tipped (Plate 8:

figure 9). The scrobicular spines may be so blunt as

to appear truncated.

The color is lost from most dried or alcohol specimens but was reported as more or less rose red or brick

red adapically by H. L. Clark (1907, p. 210).

COMPARISON WITH OTHER SPECIES—Cidaris rugosa

is compared with C. blakei in detail following the description of that species. Cidaris rugosa is readily

distinguished from Stylocidaris affinis, Stylocidaris lineata, and Tretocidaris bartletti by the lack of naked sutures, especially along the ambulacral midline. The

large globiferous pedicellariae differ also. Cidaris rugosa has a large opening below the large end tooth, S.

affinis and S. lineata lack an end tooth. Tretocidaris

bartletti has a large end tooth but below it is a very

small opening. Neither C. rugosa nor Stereocidaris ingolfiana has naked ambulacral sutures; S. ingolfiana lacks the large single end tooth on the large globiferous pedicellariae, commonly has a crest or wing on

the upper side of the primary spines, and a more jumbled arrangement of ambulacral inner tubercles.

Cidaris rugosa is readily distinguished from C. abyssicola by the large number of rudimentary tubercles

and smoother primary spines of C. abyssicola.

DISTRIBUTION.—From 32 degrees off the United

States east coast through the Greater Antilles and Lesser Antilles as far as Barbados. It is known from depths

of 130-540 meters.

Eucidaris tribuloides (Lamarck)

PLATE 1: FIGURES 1, 2, 5; PLATE 16: FIGURES 1-5; PLATE

17: FIGURES 1-7; PLATE 18: FIGURES 1-3

Eucidaris tribuloides.—For a complete synonymy and additional description see Mortensen, 1928, p. 400.

The test of Eucidaris tribuloides is moderately flattened

above and below (Plate 17: figure 5). There is a moderate incurving of the basicoronal plates at the edge of

the peristome. The test at the ambitus is commonly circular, but numerous specimens are subpentagonal and

a small percentage pentagonal. The radius in the pen-
NUMBER 40 13

tagonal specimens is greatest in the interambulacral

midzone and shortest in the ambulacra. The flattening

of the test above and below is relatively more prominent on small specimens than on large ones of 50 mm

or more. The apical system is commonly slightly larger

than one-third of the horizontal diameter of the test

and approximately the same size as the peristome. On

small to medium-size specimens the apical system may

be noticeably smaller than the peristome. The madreporite is commonly enlarged and prominent on denuded specimens.

The ambulacra are only slightly sinuate (Plate 17:

figures 4, 5). Marginal tubercles are prominent, the

bosses on some specimens contiguous and transversely

oval, arranged in uniform series. Inner tubercles crowd

the interporiferous zone and the crowding exists regardless of the presence of one, two, or three inner

tubercles per plate. Two inner tubercles per plate are

the most common, but there is only a very slight tendency for the inner tubercles to form in series.

Interambulacral plates in the region of the ambitus

are approximately twice as wide as high and have shallow small areoles. The tubercles of the scrobicular ring

are noticeably more prominent than the extrascrobicular tubercles of the interambulacral midzone (Plate 17:

figure 5). There is less difference in size between the

scrobicular tubercles and the extrascrobicular tubercles

bordering the ambulacra (Plate 17: figures 4, 5). In

the interambulacral midzone the extrascrobicular tubercles are in somewhat horizontal rows separated by

furrows. The large number of primary tubercles in

vertical series is an important diagnostic feature (Plate

17: figure 5). A specimen 35 mm in diameter commonly has 9 to 10 primary tubercles in a vertical series.

The primary spines are short, from about half the

horizontal diameter of the test to only slightly larger

than the horizontal diameter (Plate 16: figures 2-4).

They are fairly stout, either cylindrical or noticeably

tapered. The tip of the spine (Plate 17: figure 1) has

a crown formed by lamellae, each of which is at the

tip end of a row of warts (Plate 17: figures 1, 2). At

the center of the crown is a small prominence. Except

when very small, specimens lack pointed spinules. The

shaft of each spine is covered by a dense spongy covering of anastomosing hairs. The extent of development

of this covering varies between individuals. Under

water those with a very dense covering appear to have

a coat of fur (Plate 17: figure 3). The neck of the

primary spines is very short and very difficult to observe on nondenuded specimens. Oral primaries are

oval in transverse outline, only slightly different from

transitional and ambital primaries. The scrobicular

spines are broad, straight sided. The tips are very blunt

and concave, almost shovellike on some specimens

(Plate 16: figure 1).

The large globiferous pedicellariae lack an end tooth

and are similar to the kind shown in figure 4.

The specimens are brown, commonly darkest at the

collar and tips of the marginal and scrobicular spines.

The brown pigment of the primary spines is commonly

obscured by the gray or white covering of anastomosing

hairs. The denuded test is olive; the areoles white or

almost so.

Eucidaris tribuloides is usually found in fairly shallow water, but its depth range extends into the upper

limits of the distribution of Stylocidaris affinis. The two

species are commonly collected at the same station,

especially off the west coast of Florida. Very small

specimens of both species are strikingly similar but can

be differentiated by the following features.

Both species have light and dark banding of the

primary spines with well-developed thorns. Close examination of the dark bands of E. tribuloides will reveal that some of the thorns have already developed

into typical warts (Plate 18: figure 3). Observe the

dark bands nearest the base of the spines as this is

where the first warts appear. As the individual grows,

wart development progresses more rapidly in the dark

bands than the light ones, and a stage is reached where

the thorns remain only in the light bands (Plate 18:

figures 1-3). These also change to warts and the color

banding usually leaves. The crownlike tip develops on

at least one primary spine even on extremely small individuals of E. tribuloides (Plate 18: figures 1-3). One

or two very broad tipped large scrobicular spines will

be present even on the very small specimens (Plate 18:

figure 2).

The thorns on the primary spines of S. affinis remain

and, as the spines grow, simply become the spinules.

The scrobicular spines of even the smallest specimens

of S. affinis have the prominent reddish midline stripe

(Plate 18: figure5).

DISTRIBUTION.—West Indies, Gulf of Mexico, and

Bermuda. Littoral to 450 meters.
14 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Histocidaris nuttingi Mortensen

PLATE 14: FIGURES 3-5; PLATE 15: FIGURES 1-7

Histocidaris nuttingi.—For a complete synonymy sec Mortensen, 1928, p. 98; for additional descriptions see Mortensen, 1926, and 1928, p. 98.

The test is broad and quite flattened adapically (Plate

15: figure 7), widest high on the test, well rounded

above the ambitus, more tapering adorally with slight

to no incurving of the basicoronal plates. The horizontal outline is round.

The marginal tubercles are in series but not of the

normal size gradient. Size and arrangement of these

tubercles and the attached spines are important diagnostic features. A denuded ambulacrum viewed from

the horizontal position shows larger tubercles alternating down the two marginal series in a zigzag pattern

among smaller tubercles of the series (Plate 14: figure

5). This zigzag pattern is present on all four specimens available for study. The larger marginal tubercles bear proportionately longer slender spines. The

smaller marginal tubercles are very nearly equal in

size to the inner tubercles. So abundant are the inner

tubercles that they and their slender spines obscure the

midline suture.

Ambulacral plates of the peristome bear the internal

prolongation common among the histocidarids (Plate

10: figure 3).

The widest interambulacral plates are approximately twice as wide as high. Crenulation is strong

even on tubercles below the ambitus. At the ambitus

and above, the large shallow areoles crowd the adoral

transverse plate sutures distorting the curvature of the

lower side of the areole and scrobicular ring (Plate 14:

figure 4). So severe is the crowding that some of the

scrobicular tubercles are actually projections of the

lower edge of the plate situated in line with the suture.

The extrascrobicular area on each side of the scrobicular ring bears numerous secondary tubercles. Those

on the midline suture side of the plates are noticeably

arranged in nearly horizontal rows (Plate 14: figure 4).

The apical system is quite flat and has an abundance

of tubercles scattered over its surface. Tubercles on the

genital plates are most dense around the genital pores.

The very large genital pores of the MCZ specimen in

Plate 14: figure 3 suggest that it is a female. This specimen (MCZ 7729a) is approximately 75 mm in diameter and is almost the same size as the USNM specimen collected by RV Oregon at station 6699. The

USNM specimen has much smaller genital pores which

are difficult to observe due to the density of secondary

spines. A few very small plates are on the genital pore

membranes of the female MGZ 9927a. Most of the

small plates bear tubercles the same size as the tubercles on the genital plates.

The primary spines are quite varied on each individual as can be seen in Plate 15: figures 2-6. Some of the

spines are remarkably long. A medium-size specimen

35 mm in horizontal diameter (MCZ 7731) bears a

spine 150 mm in length. The ratio of spine length to

test diameter is greater in medium-size specimens than

in large ones. The shaft of the spines is smooth, shiny

and white, cylindrical to gently tapering to the tip.

Thorns are commonly scattered along the shaft at intervals of about 5 mm (Plate 15: figures 2, 3) and

arranged in three or four rows which are not easily

recognized unless viewed from the end of the spine.

The spines may terminate in a rather blunt tip or

especially on the larger specimens the tips may be

swollen or flared due to the growth of narrow expanded

longitudinal ridges limited to the tip region (Plate 15:

figure 4). Transitional spines are strongly serrate and

curve adorally (Plate 15: figure 5). Oral spines of the

basicoronal plates taper to a relatively slender tip, curve

adorally, and are markedly serrate (Plate 15: figure 6).

The large tridentate pedicellariae are diagnostic.

They are very large and easily seen with the unaided

eye and have long slender blades (Plate 15: figure 1).

The tips of the blades commonly terminate with

slightly different lengths (Plate 15: figure 1). Mortensen (1926, p. 6) suggested that this is probably due

to the tips breaking and regrowth. As with other histocidarids, H. nuttingi possesses no globiferous pedicellariae.

The medium-size specimens are all white, but the

larger specimens have white spines and some yellowish

to brownish pigment in the test.

The three histocidarids are compared and discussed

following the description of Poriocidaris purpurata

(Wyville Thomson).

Mortensen (1926) wrote his original description of

H. nuttingi without actual observation of the single

specimen available at the time. Dr. Nutting of the

University of Iowa furnished Mortensen with photographs, spines, pedicellariae, and a description of the

specimen. The holotype is presumed lost, as I have

been informed by Dr. Jerry J. Kollros, Chairman of

the Department of Zoology, University of Iowa, that
NUMBER 40 15

the specimen is not at the Museum. Fortunately specimens identified as Histocidaris nuttingi Mortensen

are in the collections—three in MCZ and one in

USNM. All four were studied and the identification

as H. nuttingi is correct. The very long slender blades

of the large tridentate pedicellariae, the slender oral

spines, white test and spines, very long thorny primary

spines, and the abundance of ambulacral inner tubercles and spines agree with Mortensen's description.

One discrepancy exists in the illustrated oral spine

of Mortensen's original description and the oral spines

observed on the basicoronal plates of the specimens

studied. The spine illustrated by Mortensen (1926, pi.

1: figs. 1, 2) is relatively longer and is identical to

the transitional spine of the third interambulacral

plate from the peristome. A spine from this position

is shown in Plate 15: figure 5, and an oral spine from

a basicoronal plate is shown in Plate 15: figure 6.

The width of the base end of the shaft is quite variable,

but all have a slender tip.

I believe that Nutting sent a transitional spine to

Mortensen and not a true basicoronal oral spine. A

close look at Mortensen's illustration of the full adoral

view (Mortensen, 1926, Plate 4: figure 11), shows

transitional and oral spines with the same shape as

those on the specimens at the Museum of Comparative

Zoology and the United States National Museum.

DISTRIBUTION.—Cuba to near Antigua at a depth

of 328 to 411 meters. So few specimens are available

that the distribution of Histocidaris nuttingi is very

inadequately known.

Histocidaris sharreri (A. Agassiz)

PLATE 12: FIGURES 1-5, 8-11; PLATE 13: FIGURES 1-3;

PLATE 14: FIGURES 1, 2

Histocidaris sharreri.—For a complete synonymy and additional description see Mortensen, 1928, p. 86.

The test is almost globular, moderately elevated at the

apical system (Plate 13: figure 1; Plate 14: figure 1),

and only very slightly flattened adorally.

The ambulacra are moderately sinuate, and have

large marginal tubercles in uniform series. The most

significant feature of the ambulacra is the near naked

interporiferous zones (Plate 12: figures 9, 11). Many

plates lack even a single inner tubercle. I believe that

the deep ambulacral midline suture which Mortensen

(1929, p. 87) suggests as being diagnostic of this species is only an irregularity or growth deformity of the

specimen he studied as it is not continuous on the

specimen. The upper portion of Plate 12: figure 11

shows the region of the ambulacrum illustrated by

Mortensen (1928, pi. 68: fig. 4). Peristomial ambulacral plates bear an internal prolongation as in other

histocidarids (Plate 10: figure 3).

Each large intermediately deep areole of the interambulacral plates is surrounded by a prominent scrobicular ring which crowds the plate sutures. The extrascrobicular area is therefore very limited, with few

secondary tubercles and spines (Plate 14: figure 1).

The primary tubercles are strongly crenulate even on

tubercles below the ambitus (Plate 14: figures 1, 2).

There is a marked difference in the relative size

of the genital pores of the two specimens studied. The

very large genital pores of the smaller specimen, MCZ

253 (Plate 12: figure 1), indicate that it is a female.

The smaller genital pores of MCZ 362 (Plate 12:

figure 10) suggest that it is a male. Tubercles of the

genital plates are most abundant around the genital

pores, and on the female form a distinct ring around

the large pores. Small tubercles are also scattered along

the periproctal edge of the genital plates.

The two specimens were too few to permit determination of the normal variation in primary spine form

and only the lower portion of two large primary spines

remain attached to MCZ 253. The length of the uppermost primary spines is approximately 1.5 times the

horizontal diameter of the test. These spines lack or

rarely possess thorns. The tips flare out (Plate 12:

figure 4) due to radial expansion of the longitudinal

ridges. At the ambitus the tips differ in that the ridges

expand to form an elongate swollen tip (Plate 12:

figures 2, 3). At or just below the ambitus the primary

spines develop two rows of serrations which become

progressively larger on transitional spines approaching

the peristome (Plate 13: figures 1, 3). Below the ambitus the spines curve adorally. The curvature increases

with adoral position. The oral primaries are broadly

rounded at the tip, transversely flat adorally, and convex adapically. The spines are strongly serrate and

curve longitudinally toward the mouth. Specimen

MCZ 362 has suffered considerable loss of spines but

a drawing in Agassiz (1883, pi. 3) shows the spine

forms and position. The tips of spines from this specimen are shown in Plate 12: figures 2—4. Only the

lower portion of two primary spines remain attached

to MCZ 253. Well-developed thorns (Plate 12: figure

1) occur on the shafts of these broken spines. There
16 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

are no thorns on the primary spines of MCZ 362. The

presence or absence of thorns is a normal variant in

the histocidarids and their absence on MCZ 362 is not

significant.

The large tridentate pedicellariae are the most diagnostic feature. They are very large, and easily observed

with the unaided eye, and have three rather long broad

blades (Plate 12: figure 5). No globiferious pedicellariae occur in any species of the histocidarids.

The specimens are brown with a small amount of

yellow pigment. The primary spines are white with a

yellow-brown collar.

The three histocidarids are compared and discussed

in detail following the description of Poriocidaris purpur ata (Wyville Thomson).

COMMENTS ON THE HISTORY AND CONFUSION ASSOCIATED WITH Histocidaris sharreri.—The echinoid that

is currently recognized as Histocidaris sharreri was

named Porocidaris sharreri in the original description

(A. Agassiz, 1880, p. 71). Three specimens, two large

males and a small female, were mentioned in this description, but it was not until the more complete

description (A. Agassiz, 1883, p. 12, pi. 3; pi. 4: figs.

1, 2), again only mentioning the three specimens,

that drawings of this species were published. Mortensen (1903, pp. 23, 28) recognized that more than

one species was represented in the descriptions

and illustrations of A. Agassiz (1880, 1883). The current name of the species that Mortensen separated

from H. sharreri is Calocidaris micans. In A. Agassiz

(1883) only the illustration in Plate 3 and a portion of

the description on pages 12 and 13 represent the

species currently recognized as H. sharreri. The specimen that A. Agassiz (1883) illustrated on plate 3 is

MCZ 362.

Following the listing of MCZ 362 in the catalog of

recent echinoid type specimens (Downey, 1968, p. 62)

is the entry "(= Calocidaris micans)." Downey in

personal communication stated that it was not intended to indicate that this specimen (MCZ 362) was

a specimen of Calocidaris micans. Specimen MCZ 362

is herein selected as the lectotype of H. sharreri, and

specimen MCZ 253 is designated a paralectotype.

The two specimens in the Museum of Comparative

Zoology (MCZ 362 and MCZ 253) are the large male

and small female mentioned by A. Agassiz (1880,

1883). The third specimen mentioned by Agassiz was

later renamed Calocidaris micans.

DISTRIBUTION.—Leeward Islands: Nevis and St.

Kitts. The distribution of all histocidarids of the northwestern Atlantic, Caribbean, and Gulf of Mexico is

inadequately known.

Poriocidaris pur pur ata (Wyville Thomson)

PLATE 10: FIGURES 2-8; PLATE 11: FIGURES 1—6; PLATE 12:

FIGURES 6, 7

Poriocidaris purpurata.—For a complete synonymy and additional description see Mortensen, 1928, p. 104.

The test is noticeably flattened adapically and adorally

(Plate 11: figure 3), with well-rounded sides. Some

specimens are widest high on the test, others widest at

the midpoint. Commonly there is no incurving of the

basicoronal plates at the edge of the peristome. A few

specimens exhibit a slight tendency toward incurving.

The ambulacra are moderately sinuate, marginal

tubercles in a uniform series, inner tubercles lacking

or very scattered in the upper portion of the ambulacra (Plate 12: figures 6, 7). Below the ambitus the

tubercles are more abundant but normally only one

or rarely two per plate. Plates lacking inner tubercles

are common throughout the ambulacra. Poriocidaris

purpurata possesses the internal prolongation (Plate

10: figure 3) on the peristomial ambulacral plates

common to the histocidarids.

The shallow areoles are very large, the scrobicular

ring circling near all the plate sutures on plates at and

above the ambitus (Plate 11: figures 1, 3). Only a

few extra scrobicular secondary tubercles occur on

these plates. Below the ambitus the extrascrobicular

areas at each side of the areoles are relatively larger

and are accompanied by a proportionate increase in

secondary tubercles (Plate 11: figure 2). Primary

tubercles are crenulate even below the ambitus but

strongly crenulate on the uppermost two or three of

each series.

Primary spines are 2 to 2.5 times the horizontal

diameter of the test, are cylindrical or slightly tapering. A few specimens with a few well-developed thorns

on some spines have been collected from the eastern

Atlantic. Normally numerous very small ridges of

spinules run the length of the shaft. The spinules are

directed strongly toward the tip of the spine. The collar on the uppermost primary spines of some specimens extends for a considerable distance up the spine.

Some spines with long collars have a swelling in the

collar. Purple to brownish pigment is common in the

collar but the shaft is usually white.
NUMBER 40 17

The oral primary spines are strongly serrated,

broadly rounded at the tip (Plate 11: figure 6) transversely convex on the adapical side flat on the adoral

side. Longitudinally, these spines curve toward the

mouth.

The most important diagnostic feature of P. purpurata is that its tridentate pedicellariae are bivalved

and very strongly compressed (Plate 10: figure 2).

The color is quite varied. Specimens range from

white to dark brownish purple test and secondary

spines. The primary spine shaft is white, but the collar

is the color of the test and secondary spines.

DISTRIBUTION.—South of Ireland to the Canary

Islands. It was not previously known to occur in the

western Atlantic. I discovered two specimens, one at

the United States National Museum, the other at the

Museum of Comparative Zoology at Harvard University. The specimen in the USNM (E-8244) was collected by RV Oregon at station 1909, 11 September

1957, 12°35'N, 82°19'W in the Caribbean Sea at 350

fms. The other specimen (MCZ 7732) was collected

at Nicholas Channel off Bahia de Santa Clara at 500

fms, Atlantis station 3459.

COMPARISON WITH OTHER SPECIES.—The three histocidarids, Histocidaris nuttingi, H. sharreri, and Poriocidaris purpurata, can readily be distinguished from

the other cidaroids of the northwestern Atlantic, Caribbean, and Gulf of Mexico by the lack of globiferous

pedicellariae. Internally all three of the histocidarids

have a prolongation on the peristomial ambulacral

plates (Plate 10: figure 3) lacking in the other cidaroids of this region. Crenulation is strong all around

the upper primary tubercles and present on tubercles

well below the ambitus on the histocidarids. There is

varied development of crenulation among the other

cidaroids of the region but on none of them does it

extend below the ambitus.

The naked tests of H. sharreri and P. purpurata are

similar. Both have very large areoles, scrobicular rings

that crowd their plate sutures especially at and above

the ambitus, and very few extrascobicular secondary

spines and tubercles. There are only a few inner tubercles in the ambulacral midzone of each species; possibly

slightly more on P. purpurata than on H. sharreri.

The ambulacral midzones of H. sharreri and P.

purpurata have few inner tubercles, but the midline

suture is almost hidden by the abundant inner tubercles

on H. nuttingi. The marginal tubercles of H. sharreri

and P. purpurata are arranged in a uniform size gradient throughout the ambulacra; small adapically on

small plates larger at the ambitus. Histocidaris nuttingi has large marginal tubercles separated by smaller

ones approximately the same size as the inner tubercles.

The large marginal tubercles in each series of an ambulacrum form a zigzag pattern.

The large tridentate pedicellariae are a diagnostic

feature on each of these species. Histocidaris sharreri

has three very broad large valves on each of its large

tridentate pedicellariae (Plate 12: figure 5), whereas

those of H. nuttingi are very long and slender (Plate

15: figure 1). All the pedicellariae on P. purpurata

have two highly compressed valves. The small tridentate pedicellariae of H. sharreri and H. nuttingi are

similar.

The collar on the uppermost primary spines of all

three of these histocidarids commonly extends far up

the shaft. This feature was previously considered diagnostic for P. purpurata. Thorns are uncommon on the

primary spines of P. purpurata, common on those of

H. nuttingi, of uncertain occurrence on H. sharreri.

Thorn occurrence on H. sharreri is discussed in the

description of the primary spines of that species.

Poriocidaris purpurata is distributed from south of

Ireland to the Canary Islands and in the Caribbean

Sea at depths of approximately 750-1,800 meters.

Stereocidaris ingolfiana Mortensen

PLATE 22: FIGURES 3-9

Stereocidaris ingolfiana.—For a complete synonymy iee Mortensen, 1928, p. 267; for additional descriptions see Mortensen, 1903, p. 38, and 1928, p. 267.

The test is flattened above and below, sides well

rounded (Plate 22: figure 5). There is a very slight

incurving of the basicoronal plates at the edge of the

peristome. The height is commonly about 0.55 of the

horizontal diameter, but a few specimens with relatively globular tests have been observed (Mortensen,

1903, p. 38; 1928, p. 268). The horizontal outline of

the test is round.

The ambulacra are moderately sinuate, marginal

tubercules in a uniform series. The ambulacral midzone is a jumble of inner tubercles which obscure the

midline suture even on a denuded test (Plate 22:

figure 6).

The interambulacral midline suture commonly has a

dimplelike depression at each corner of the interambulacral plates (Plate 22: figure 7). These are not
18

true pits as in the temnopleurids, but they are readily

observed on the denuded test. There are only a few

rudimentary tubercles (Plate 22: figure 3), areoles are

large and deep, the lower two in a series commonly

confluent (Plate 22: figure 4). The scrobicular ring of

tubercles is only slightly conspicuous, extrascrobicular

area very limited. Mortensen (1903, p. 38) reported

the secondary tubercles arranged in horizontal rows on

large specimens. His largest specimens were 32 and 38

mm in diameter. I did not study any specimens that

large, but on specimens 21 to 26 mm I did not see any

tendency of alignment into rows. The extrascobicular

area is so narrow on these specimens that there is insufficient space for rows to develop (Plate 22: figure

7). None of the interambulacral sutures appear naked.

The spinules of the uppermost longitudinal series on

the primary spines grow longer than the other spinules

and are fused together. Where this condition is highly

developed, the spinule series forms a wing (Plate 22:

figures 8, 9). The wing is common on the upper side

of the spine, but a few spines may have an additional

wing or two. The second wing most commonly develops

on the underside of the spine. The spinules of the

uppermost row are enlarged and united as if melted

together on primary spines when a wing is not apparent. A row of numerous small serrations is on each edge

of the oral spines and on the lowermost one or two

transitional spines.

The apical system lacks features significant enough

to aid readily in identification.

The large globiferous pedicellariae lack the single

large end tooth of Calocidaris and Cidaris. The closed

space between the end tooth and the blade opening is

also lacking in S. ingolfiana. The opening is subterminal, rather large, narrower above than below, surrounded by teeth. The top of the opening is near the

tip of the blade. The two uppermost teeth are larger

than the others. These tend to fuse on some valves, giving the superficial appearance of a single end tooth.

The two larger teeth fused or unfused are at the upper

edge of the opening and not separated from the opening by a closed space as in Cidaris and Calocidaris.

The specimens are almost white, but a slight pink

tint occurs in the primary spines of some specimens.

COMPARISON WITH OTHER SPECIES.—Stereocidaris

ingolfiana can be distinguished readily from Stylocidaris affinis and S. lineata by the lack of naked sutures,

and especially by the jumble of inner tubercles in the

midzone of Stereocidaris ingolfiana obscuring the midSMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

zone suture. Stereocidaris ingolfiana can readily be distinguished from Histocidaris and Poriocidaris purpurata by the lack of distinct crenulation and possession of

globiferous pedicellariae. Histocidaris sharreri and P.

purpurata have very few inner tubercles in the ambulacra, only H. nuttingi has a cluttered ambulacral midzone, but it has large and small marginal tubercles.

Stereocidaris ingolfiana has uniform marginal tubercles. Tretocidaris bartletti has strong crenulation on the

upper side of the upper tubercles, naked sutures, and

an uncluttered ambulacral midzone. Cidaris and Calocidaris micans have a well-developed single end tooth

on the large globiferous pedicellariae, but S. ingolfiana

lacks the single large end tooth. The very obscure ambulacral midline suture of S. ingolfiana and the "wing"

on the primary spines also distinguishes S. ingolfiana

from Cidaris and Calocidaris micans.

Stereocidaris is noted for the abundance of rudimentary tubercles, and interambulacral plates higher than

wide on its adapical side. Some species from the Pacific

and also some fossils have few fully developed tubercles

visible when viewed from above.

Stereocidaris ingolfiana has far fewer rudimentary

tubercles than one would expect in this genus (Plate

22: figures 3, 5). The absence of the single end tooth

on the large globiferous pedicellariae offers the

strongest evidence that it is a Stereocidaris.

Cidaris abyssicola has many rudimentary tubercles

(Plate 5: figure 1), and indeed a fossil so well endowed could easily be assigned to the genus Stereocidaris. This feature distinctly distinguishes it from all

the other species of Cidaris in the northwestern Atlantic and the Gulf of Mexico. Neither species has a

markedly higher-than-wide ratio of upper interambulacral plates so characteristic of some Stereocidaris species. The ambulacral interporiferous zones of both

species are crowded with inner tubercles. Those of C.

abyssicola tend to be more organized into a series

(Plate 5: figure 4). Those of S. ingolfiana are jumbled,

the midline often difficult to distinguish (Plate 22:

figure 6).

Specimens of C. abyssicola with two inner tubercles, one above the other adjacent to the marginal

tubercles (Plate 5: figure 4), have a very crowded

interporiferous zone but the series of tubercles is quite

pronounced.

DISTRIBUTION.—Northern Atlantic from the Denmark Strait to Cape Verdes on the eastern side and

into the Caribbean on the western side at depths of

300 to 1,745 meters.
NUMBER 40 19

Stylocidaris affinis (Philippi)

PLATE 18: FIGURES 4—6; PLATE 19: FIGURES 1, 3} 7; PLATE

20: FIGURES 4, 5

Stylocidaris affinis.—For a complete synonymy and additional

description see Mortensen, 1928, p. 336.

Test flattened above and below, circumference round,

basicoronal plates slightly incurving at the edge of the

peristome.

Ambulacra are moderately sinuate; marginal tubercles in uniform series. Commonly there is only one inner

tubercle per plate, located on the lower portion. A

very small granule is commonly found just above it.

Two additional granules are on the lower edge of the

plate just below the marginal tubercle (Plate 20:

figure 5). All these granules may be indistinguishable

without special preparation of the test. The midline

suture is white and very naked (Plate 19: figure 3).

The areoles of the interambulacra are quite large,

well separated, even the lowermost two in a column

are commonly not confluent. Areoles in the ambital

region are moderately deep. Large specimens lack crenulation on the tubercles. I have observed crenulation

on very small specimens up to 5 mm in diameter, but

found it absent on specimens 10 mm and larger. The

scrobicular ring of tubercles is rather inconspicuous.

Interambulacral and ambulacral midline sutures are

naked and white.

The apical system is covered with coarse round

granular tubercles (Plate 19: figure 1) except on very

small specimens only a few millimeters in horizontal

diameter, which have radially elongate tubercles.

Specimens large enough to be easily studied with the

unaided eye have developed the round tubercles.

The length of the primary spines is from 1 to 1.5

times the horizontal diameter of the test. Some young

specimens have spines up to twice the horizontal diameter of the test. The spines are rather slender tapering toward the tip, rows of rather coarse spinules can

be observed by the unaided eye. There is a short naked

neck between the collar and the rows of spinules. The

scrobicular spines are very diagnostic. The most important feature is the dense reddish to reddish brown

stripe of pigment running through the midline on the

exposed side of the spine. The edges of these spines are

white or white with a slight greenish tint. These spines

taper in the distal portion toward a cutoff or blunt tip

(plate 18: figure 4). The oral spines have rows of

blunted spinules and lack serrate edges, are only

slightly flattened and terminate in a blunt tip.

The large globiferous pedicellariae lack an end tooth.

The test is white to slightly olive. Red to reddishbrown pigment is abundant in the apical system and

in a midline stripe on the scrobicular and marginal

spines. The collar and neck of primary spines commonly have the reddish pigment, especially on specimens with reddish-brown banded spines. Some specimens have white or slightly olive spines without color

bands. Color banding is most prevalent on small

specimens.

COMPARISON WITH OTHER SPECIES.—The tests of

Tretocidaris bartletti and Stylocidaris affinis are quite

similar, but the strong crenulation on the upper side of

the upper tubercles on Tretocidaris bartletti (Plate 21:

figure 4) distinguishes it from Stylocidaris affinis,

which lacks crenulation except on very small

specimens.

The granules around the periphery of the apical

system tend to elongate in a radial direction on T. bartletti (Plate 21: figure 2) while those of S. affinis are

round (Plate 19: figure 1).

The ambulacra of the two species are very similar

(Plate 20: figure 5; Plate 21: figure 1).

The spinules on the upper side of the primary spines

are more fully developed than those on the underside

on T. bartletti (Plate 21: figures 5,6; Plate 22: figures

1, 2). This feature is helpful also in identifying very

small specimens only a few millimeters in diameter.

The white scrobicular spines are an added identifying

feature. Stylocidaris affinis has spinules of uniform size

around the primary spines and a reddish midline stripe

on the scrobicular and marginal spines.

Stylocidaris affinis and Stylocidaris lineata are

superficially similar but are easily distinguished. The

more colorful is S. affinis (Plate 20: figure 4), with reddish pigment throughout the plates of the apical

system, reddish stripe down the midline of the scrobicular and marginal spines (Plate 19: figure 3), and commonly especially in small specimens reddish to brown

banding of the primary spines (Plate 18: figures 5, 6).

The rest of the echinoid is white to slightly olive. Stylocidaris lineata is white or almost so. The only noticeable color is the reddish-brown naked midline sutures

of the ambulacra (Plate 19: figure 4), the sutures of

the interambulacra, and the reddish-brown ring in the

apical system (Plate 19: figure 5). These reddishbrown sutures and ring in the apical system are the

most distinguishing features. The sutures of S. affinis

are white (Plate 19: figure 3).
20

The apical system of S. affinis is covered with round

granules (Plate 19: figure 1), whereas S. lineata lacks

granules in the region of the naked reddish ring. The

granules on either side of the ring are radially elongate

(Plate 19: figure 2).

Many specimens of these species were studied at the

U.S. National Museum and at the Museum of Comparative Zoology. Only one specimen of S. affinis was

found with an apical system similar to S. lineata. All

specimens of S. lineata have the apical system here described. Collections commonly have both of these species identified as S. affinis, and the worker must be

careful to identify specimens himself rather than to

rely on existing labels.

The primary spines of S. lineata are somewhat longer

than those of S. affinis. The length of the naked neck

and number of spinule rows are too variable to distinguish the species.

The large globiferous and large tridentate pedicellariae of S. lineata have longer more slender valves

(Plate 19: figure 6) than those of S. affinis (Plate 19:

figure 7).

Eucidaris tribuloides is usually found in fairly shallow water, but it extends into the upper limits of the

distribution of S. affinis. The two species are commonly

collected at the same station especially off the west

coast of Florida. Specimens of both species only a few

millimeters in diameter are strikingly similar, both

having light and dark banding of the primary spines

with well-developed thornlike spinules (Plate 18: figures 1-3,5). The wartlike spinules of E. tribuloides first

appear in the dark bands nearest the base of the primary spines. Wart development progresses more rapidly

in the dark bands as the individual grows. The thorns

remain only in the light bands on slightly larger

specimens (Plate 18: figures 2, 3). These also change to

warts and the color banding is commonly lost. The

spinules do not develop into warts on S. affinis. A

crownlike tip commonly develops on at least one primary spine even on extremely small individuals of E.

tribuloides (Plate 18: figure 3). A distinguishing feature is that one or two very broad tipped large scrobicular spines (Plate 18: figure 2) are commonly present

even in the smallest specimens of E. tribuloides.

Stylocidaris affinis has a reddish midline stripe on the

scrobicular and marginal spines even when very small

(Plate 18: figure 5).

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

DISTRIBUTION.—Bermuda, the West Indies, Caribbean Sea, Gulf of Mexico, eastern Atlantic, and the

Mediterranean Sea at depths of 30 to 1,000 meters.

Stylocidaris lineata Mortensen

PLATE 19: FIGURES 2, 4-6; PLATE 20: FIGURES 1-3

Stylocidaris lineata.—For a complete synonymy see Mortensen, 1928, p. 342; for an additional description see

Mortensen, 1910, p. 10.

The naked test of S. lineata is indistinguishable from

that of S. affinis except for the apical system and suture

color. Only these features are discussed here.

The apical system has a reddish nearly naked ring

lacking granular tubercles crossing all genital plates

(Plate 19: figures 2, 5). The granules on either side

of the naked ring are radially elongate. The ambulacral

midline suture and all interambulacral sutures are reddish brown (Plate 19: figures 4, 5), even on specimens

only a few millimeters in diameter. This is a very important diagnostic feature of S. lineata and probably

the least variable, because the color is almost always

the same and withstands years of alcohol and dry storage with great durability. The primary spines are white

with delicate spinules, visible to the naked eye. Length

of the spines is from 1.5 to slightly more than 2 times

the horizontal diameter of the test. The scrobicular and

marginal spines are white and lack a midzone stripe.

COMPARISON WITH S. affinis.—Three significant

features distinguish S. lineata from S. affinis. The

scrobicular and marginal spines of S. lineata are white

and without a midline stripe, whereas those of S.

affinis have a prominent reddish-midline stripe with a

white to greenish edge (Plate 18: figure 4; Plate 19:

figure 3). The apical system of S. lineata has a naked

reddish ring lacking small granular tubercles. The

tubercles are radially elongated on each side of the

ring. No naked ring is present in the apical system of

S. affinis. The tubercles are round and scattered over

the apical system (Plate 19: figure 1), which is commonly reddish to reddish brown. The midline sutures

of the ambulacra and all interambulacral sutures of

S. lineata are reddish brown (Plate 19: figure 4).

Whereas those of 5". affinis are white (Plate 19: figure

3). Additional comparisons follow the description of

S. affinis.

The description of the naked test of S. affinis applies

to S. lineata with the exception of the apical system

and the suture color.
NUMBER 40 21

DISTRIBUTION.—West Indies, at depths of 100-500

meters. It may be frequently found living with S.

Tretocidaris bartletti (A. Agassiz)

PLATE 21: FIGURES 1-7; PLATE 22: FIGURES 1, 2

Tretocidaris bartletti.—For a complete synonymy see Mortensen, 1928, p. 315; for additional description see Mortensen, 1910, p. 5.

The test of Tretocidaris bartletti is rather low, approximately .55 of the horizontal diameter, flattened above

and below. The apical system is very slightly elevated,

highest point is in the periproct. The basicoronal plates

have a very slight tendency to incurving at the edge

of the peristome. Ambulacra are moderately sinuate,

marginal tubercles in a uniform series. There is one

small inner tubercle low on each ambulacral plate

(Plate 21: figure 1) except on newly introduced plates

at the adapical end of the column. The inner tubercles

are in series. The interambulacral areoles are large and

shallow, two lowermost confluent. The upper side of

the uppermost tubercles are crenulate. Crenulation

commonly extends all the way around a few of these

tubercles, but it is more prominent on the uppermost

portion (Plate 21: figure 4). The scrobicular rings

of tubercles are fairly prominent. They circle close to

all plate sutures limiting the extrascrobicular area

which bears few secondary tubercles. The interambulacral midline suture is naked. Granules on the periphery of the apical system are elongated radially

(Plate 21: figure 2).

The primary spines are cylindrical to very gently

tapering, with their length approximately 1.5 times

the horizontal diameter of the test. The spinules of

the upper side are larger than those of the underside.

These upper spinules of some specimens are very large

and very conspicuous (Plate 22: figures 1, 2). A hand

lens may be required to observe the difference in spinule size on other specimens (Plate 21: figure 7). A

spine between these two extremes is shown in Plate

21: figures 5, 6. Regardless of the degree of development, the upper side spinules are larger than those

on the underside.

The primary spines are color banded, but this is less

important because some other cidaroids also commonly

have color-banded spines. The reddish-brown bands

range from very wide to very narrow. Regardless of

the pattern, banding is a constant feature. The underside of the spine has greatly reduced pigment and is

almost white (Plate 22: figure 2).

The oral primary spines have a thin ridge on each

side which commonly has inconspicuous closed serrations. The large globiferous pedicellariae of this species

are very significant, being quite different from those of

any other species. The single end tooth is quite long

and prominent, and the blade opening is very small

(Figure 3) commonly surrounded by a ring of very

small teeth. Above the opening is a short closed space

separating the long slender end tooth from the blade

opening. This very small blade opening is the most

significant diagnostic feature of T. bartletti.

The specimens are quite white except for the brown

to brownish-red color banding of the primary spines.

The same color is commonly found to varying extents

in the apical system and areoles. Naked sutures are

white. Scrobicular spines are white or white with a

weak greenish-brown midline.

COMPARISON WITH OTHER SPECIES.—Tretocidaris

bartletti has a large single end tooth and a very small

opening in the blades of the large globiferous pedicellariae. The large globiferous pedicellariae of S. Affinis

and S. lineata lack a large single tooth. Cidaris and

Calocidaris micans have a large end tooth, and a large

blade opening on the valves of their large globiferous

pedicellariae.

The crenulation on the upper side of the uppermost

primary tubercles always present in T. bartletti also

occurs on some specimens of other species which commonly lack crenulation. The tests of Stylocidaris affinis

and S. lineata are very similar to the test of T. bartletti,

but lack crenulation except when only a few millimeters

in diameter. The reddish-brown sutures of S. lineata

distinguish it from T. bartletti which has white sutures.

The scrobicular spines of S. lineata are very similar

to those of T. bartletti, but the scrobicular spines of

S. affinis bear a strong reddish to reddish-brown midline stripe. The scrobicular spines of T. bartletti are

white or bear a weak greenish to greenish-brown midline, not as distinct as that of S. affinis. The spinules on

the upper side of the primary spines of T. bartletti are

markedly larger than those of the underside. This is a

distinct feature of this species.

DISTRIBUTION.—West Indies and Caribbean Sea at

depths of 140 to 625 meters.
22

Literature Cited

Agassiz, A.

1880. Preliminary Report on the Echini, in Reports . . .

of Dredging .. . by the . . . Steamer "Blake" . . .,

9, Bulletin of the Museum of Comparative Zoology,

at Harvard College, 8(2): 68-84.

1883. Report on the Echini, in Reports .. . of Dredging

. . . by the .. . Steamer "Blake" . . ., 24, part

1, Memoirs of the Museum of Comparative Zoology,

at Harvard College, 10(1): 1-99, 22 Plates.

Clark, H. L.

1907. The Cidaridae. Bulletin of the Museum of Comparative Zoology, at Harvard College, 51(7): 163—

230, 11 Plates.

Downey, M.

1968. Catalog of Recent Echinoid Type Specimens in

the U.S. National Museum, Smithsonian Institution, and the Museum of Comparative Zoology,

SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

Harvard University. United States National Museum Bulletin, 264:1-101.

Mortensen, T.

1903. Echinoidea. The Danish Ingolf-Expedition, Lundbeck, T., Translator, 4(1): 1-194, 21 Plates, 12

figures. Copenhagen: Bianco Luno.

1910. On Some West Indian Echinoids, United States

National Museum Bulletin, 74:1-33, 17 Plates.

1926. A New West Indian Cidarid. In H. Wickham,

Editor, Echinoderms and Insects from the Antilles.

University of Iowa Studies in Natural History,

9(7): 5-8, Plates 1-4.

1928. A Monograph of the Echinoidea, Cidaroidea.

1:1-551, 88 Plates, 173 figures, Copenhagen:

Bianco Luno.

Teichert, C.

1948. A Simple Device for Coating Fossils with Ammonium Chloride. Journal of Paleontology, 22(1):

102-103.

Index

Calocidaris micans (Mortensen), 8

Cidaris abysskola (A. Agassiz), 9

Cidaris blakei (A. Agassiz), 10

Cidaris rugosa (H. L. Clark), 11

Eucidans tribnloides (Lamarck), 12

Histocidaris nuttingi Mortensen, 14

Histocidaris sharreri (A. Agassiz), 15

Poriocidarispurpurata (Wyville Thomson), 16

Stereocidaris ingolfiana Mortensen, 17

Stylocidaris qffinis (Philippi), 19

Stylocidaris lineata Mortensen, 20

Tretocidaris bartletti (A. Agassiz), 21
PLATES
24 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 1

Diagnostic features common to all cidaroids:

1. The tooth lacks a keel.

2. The top of the junction of pyramid halves is higher than the lowest part of the epiphyses (see

Figure 1). The compasses have been removed from the figured lantern.

5. The prominent lantern supports are interambulacral apophyses.

7. The series of ambulacral plates continues across the peristome to the mouth. There are no gill

notches on the peristomial edge of the test as on noncidaroid rigid test sea urchins (Plate 1:

figure 8) Cidaris abyssicola (A. Agassiz), X 1.5.

Noncidaroid features:

3. The top of the junction of pyramid halves is lower than the lowest part of the epiphyses (see

Figure 1).

4. The tooth has a keel.

6. The prominent lantern supports are ambulacral auricles.

8. Gill notches on the peristomial edge of the test.
NUMBER 40
26 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 2

Calocidaris micans (Mortensen), USNM 10717:

1. Details of an interambulacral plate and a portion of an ambulacrum, X 4.

2. Side view of test, note slightly sunken interambulacral midzone, X 1.5.

3. Adoral side of the base of a large primary spine, note shiny surface and absence of crenulation,

X 7.

4. Apical system, note pentagonal periproct common to the cidaroids, X 4.

5. Adapical side of primary spine in figure 3 showing crenulation matching that of a tubercle

such as in figure 1, X 7.

6. Portion of an ambulacrum showing typical arrangement of pore pairs, marginal tubercles, and

inner tubercles, X 6.

7. Scrobicular spine, X 6.

8. Adapical view of test, X 6.
NUMBER 4 0 27

• *. 1

^ il

i ^31

(C? *• •

.' pi

•

•T - 2L^5

| ft i

at'1* * * *

-

,'&\***' 7 • '

.$}$>: ,it.

J&.''•::'}.'. '.V:

•

• *

V '

•

j

i

6

1 £

I • W

r

* .J

•%

7

8

• \

V

A! * *

t i

•

•

•

A * *

• V

1

1

* •• «

•

r

• •

• •

H

V

J

5^

ft*

• ^'\**.

f

— - ^_ji

9

•.

f

"* ll'Wll'IIWIllHllKJ
28 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 3

Calocidaris micans (Mortensen), USNM 10717:

1, 7. Adapical and adoral views, X 0.5.

2, 5, 6. Adapical, adoral, and ambital portions of an ambulacrum, X 6.

3. Oral primary spine, X 9.

4. Primary spine, X 0.9.
NUMBE

R 4 0

29
30 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 4

Cidaris abyssicola (A. Agassiz):

1. Tip of primary spine showing hollow "hoof," X 6, USNM 7615.

2. 6. Adapical and side views showing flattened adapical area and horizontally directed primary

spines, X 1, USNM 7615.

3. Adapical end of an ambulacrum, X 4.

4. A fairly smooth chalky white primary spine, X 1.2.

5. A transitional primary spine from the adoral side of the test, X 2.
NUMBER 4 0 31

660-863—69
32 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 5

Cidaris abyssicola (A. Agassiz):

1, 2. Adapical and side views of denuded test, X 1.5.

3. Slender spine form which Mortensen referred to as C. abyssicola var. teretespina, X 1.

4, 5. Ambital and adoral views of an ambulacrum, X 4.

6. Scrobicular spines covering the muscles of a primary spine, X 5, USNM 7615.
NUMBER 4 0 33
3 4 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 6

Cidaris blakei (A. Agassiz):

1. Adapical view of test, X 2, USNM E3933.

3. Portion of an interambulacrum showing very large areoles and sparsity of very fine extrascrobicular tubercles, X 4, MCZ 155.

5. Apical system showing fine granular tubercles, X 4, MCZ 155.

Cidaris rugosa (H. L. Clark) :

2. Adapical view of test, X 1.5, USNM E10329.

4. Portion of an interambulacrum of a paratype showing relatively larger extrascrobicular area

and tubercles than those of C. blakei in figure 3, X 4, MCZ 167.

6. Apical system of a paratype showing relatively coarse granular tubercles, X 4, MCZ 167.
NUMBER 4 0 35

1 <

I

x * .*

i U

:• • • v

3

4

i

»- i

d

5 * J

y

(

F " r:. **J:-«".• * » * <* »-• ;• '

,< >f* * "rv . ••»

•/* *• i;:

I e

-:

• •

• S^ * i

f

* . * • m '•*

c

4

mL ,4 m

f

' J?& \if;.;.' • J*SSSi?s

6

if

Sir -/'-I." ' '•:•••

*» • • •

^ ^

• #

V

••». •

- %v*

••* • . •

A••• «• • •
36 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 7

Cidaris blakei (A. Agassiz), USNM E3933:

1. Side view of test, X 2.

6, 7, 8. Adapical, ambital, and adoral views of an ambulacrum, X 6.

Cidaris rugosa (H. L. Clark):

2. Side view X 1.5, USNM E10329.

3. 4, 5. Adapical, ambital, and adoral views of an ambulacrum, X 4.5, USNM 21444.

9. Ambital view of an ambulacrum, X 4.5, USNM El0329.
NUMBE

R 4 0

37
3 8 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 8

Cidaris blakei (A. Agassiz) :

1, 2. Fan-shaped adapical primary spines of an exceptionally well-developed specimen, X 1.5,

USNM E3933.

3, 4. Slightly flattened ambital primary spines similar to the adapical spines of some specimens,

X 1.5, USNM E3933.

5. Primary spine from below the ambitus without flattened tip, X 1.5, USNM E3933.

8. Close-up view showing the more pointed slim marginal spines of C. blakei as compared with

C. rugosa in figure 9, X 8, USNM E8697.

Cidaris rugosa (H. L. Clark):

6. Primary spine with flattened tip, X 1.5, USNM E10329.

7. Primary spine with swollen area near collar, X 1.5, USNM 21444.

9. Close-up view showing broader blunter marginal spines of C. rugosa as compared with C. blakei

in figure 8, X 7, USNM 21463.
NUMBER 4 0 39
4 0 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 9

Cidaris blakei (A. Agassiz):

1, 2. Adapical and side views of a specimen with exceptionally well-developed fanlike adapical

primary spines, X 1, USNM E8697.
NUMBER
42 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 10

Cidaris rugosa (H. L. Clark):

1. Adapical view, X 1,USNM 21463.

Poriocidaris pur pur at a (Wyville Thompson):

2. Bivalve tridentate pedicellaria, X 20, USNM E8244.

3. Internal view of a portion of the peristome showing the prolongations on the ambulacral

plates, a diagnostic feature of all histocidarids, X 9, USNM £8244.

4. 5, 6. Tip of cylindrical, tapered, and slightly tapered cylindrical primary spines, X 4, USNM

E8244.

7. Crenulation on adapical side of primary spine base, X 4, USNM E8244.

8. Adoral side of primary spine base showing absence of crenulation, X 4, USNM E8244.
NUMBER 40
4 4 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 11

Poriocidaris pur pur at a (Wyville Thompson):

1, 2, 3. Adapical, adoral, and side views, X 2.5, USNM E8244.

4. Adapical view partially denuded, X 1, USNM E8244.

5. Adapical view of eastern Atlantic specimen, X 1, USNM 27675.

6. Oral primary spines, notice the blunt rounded tips and prominent serration, X 6, USNM

E8244.
NUMBER 4 0 45
46 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 12

Histocidaris sharreri (A. Agassiz).

Paralectotype, MCZ 253:

1. Adapical view of the test, notice the large female genital pores, X 1.5.

8, 9. Adapical and ambital views of an ambulacrum, X 5.

Lectotype, MCZ 362:

2, 3, 4. Tips of primary spines, X 2.

5. Large tridentate pedicellaria, X 6.

10. Apical system, X 2.

11. Ambital view of denuded portion of an ambulacrum, note that the deeply sunken suture, a

deformity, is limited to a small area in the upper portion of the figure, X 6.

Poriocidaris pur pur at a (Wyville Thomson), USNM E8244.

6 7. Adapical and ambital view of an ambulacrum, X 7.
NUMBER 4 0 47
48 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 13

Histocidaris sharren (A. Agassiz), lectotype, MCZ 362:

1, 2, 3. Side, adapical, and adoral views, X 0.75.
NUMBE

R 4 0

49
50 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 14

Histocidaris sharreri (A. Agassiz), paralectotype, MCZ 253:

1, 2. Side and adoral views, X 1.5.

Histocidaris nuttingi Mortensen, MCZ 7729A:

3. Apical system showing large female genital pores, X 2.

4. Ambital view of test, note how the scrobicular ring crowds the lower plate suture, X 2.

5. Ambulacrum showing the zigzag pattern of large marginal tubercles, X 4.
NUMBER 4 0 51
5 2 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 15

Histocidaris nuttingi Mortensen, MCZ 7729A:

1. Tridentate pedicellaria, note the uneven length of the long narrow blades, X 12.

2, 3. Large shiny thorny primary spine, X 2.

4. Curved primary spine lacking thorns, X 1.5.

5. Transitional primary spine, X 2.

6. Oral primary spine, X 2.

7. Side view, X 1.
NUMBER 40
5 4 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 16

Eucidaris tribuloides (Lamarck):

1. Close-up of broad shovellike tips of scrobicular spines, X 8.

2, 3, 4. Adapical, adoral, and side views, X 1.

5. Close-up of ambulacrum showing broad tipped marginal spines, X 8.
NUMBER 40 55

359-863—69 5
5 6 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 17

Eucidaris tribuloides (Lamarck) :

1. Crown at tip of primary spine, X 9.

2. Denuded primary spine, X 3.

3. Wet uncleaned primary spine showing the common furlike covering, X 3.

4. Ambital view of an ambulacrum, X 6.

5. 6, 7. Side, adapical, and adoral views, X 2.
NUMBER 40 57
58 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 18

Eucidaris tribuloides (Lamarck), very small specimen:

1. Adapical view, X 4.

2, 3. Close-up view, note broad tipped scrobicular spines, thorny spinules in light bands, and

warty spinules in dark bands near base of primary spines. Crowns are well developed at tips

of primary spines, X 6.

Stylocidaris affinis (Philippi):

4. Scrobicular spine showing reddish mid line stripe, X 10.

5. Adapical view of very small specimen, not that thorny spinules occur in light and dark primary

spine bands, reddish stripe on scrobicular and marginal spines, X 4.

6. Larger specimen than in figure 5, note naked sutures, side view, X 1.
NUMBER 40 59
6 0 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 19

Stylocidaris affinis (Philippi) :

1. Apical system, note the even distribution of round granular tubercles, X 4.

3. Close-up, note naked white sutures, midline stripe on marginal and scrobicular spines, X 4.

7. Large globiferous pedicellariae, X 40.

Stylocidaris lineata Mortensen:

2. Apical system, note radially elongate tubercles and naked ring, X 4.5.

4. Close-up, note naked reddish ambulacral suture and white unstriped marginal and scrobicular

spines, X 3.

5. Adapical view, note reddish naked ring in apical system, X 3.

6. Large globiferous pedicellaria, notice the longer narrower valves when compared to S. affinis

in figure 7, X 40.
NUMBER 40 61

. c . ' • . "

• • . a •

s&: :•''•'-'. -

. • * ' ^ TT W* .

• • • • • ' • •;;.•. • •

• • * • . * - - , •

. • • . • '•>:>•"•>/•«

:p. -; : f» ^

.'.' ' • •' *• •

. • . • * . • .

3 \ '»

6

 1k

• - •. > • • *•*•.*

'.;. •.. £» *•

-: •.•'?•'.••

- i 1 •*• • < • • .

*. ' . .' •

r

 * * ' • ' • ".*•

k * • w •

7

V

••', '•

•./ .

•-•

:: >

V

1

f

r

4*"' \

/;•*- '*«

2

1

bt i n

•nil

\.

1

1 1

i

1

SB

t* * * • •'• . *

* • - r , -

' * » **',> t ••• »

g * * *'

\ •

r -

i

i

• ^ vil t
6 2 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 20

Stylocidaris lineata Mortensen:

1, 3. Adapical and side views, X 1.

2. Ambital portion of an ambulacrum, note the similarity to figure 5 and Plate 21: figure 1, X 10.

Stylocidaris affinis (Philippi):

4. Adapical view, X 1.25.

5. Ambital portion of an ambulacrum, X 7.
NUMBER 40 63
64 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 21

Tretocidaris bartletti (A. Agassiz), USNM 6836:

1. Ambital portion of an ambulacrum, X 3.

2. Apical system, X 5.

3. Side view, X 3.

4. Oblique view of adapical side showing crenulation on upper side of upper primary tubercles,

X 5.

5. Primary spine, adapical side, note large spinules, X 2.

6. Adoral side of primary spine in figure 5, note small spinules and lighter color, X 2.

7. Adapical side of small spinule form of primary spine, X 2.
NUMBER 4 0 65
6 6 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY

PLATE 22

Tretocidaris bartletti (A. Agassiz) :

1. Primary spine with very thorny spicules, adapical side, X 1.5, MCZ 159.

2. Adoral side of primary spine in figure 1, note greatly reduced size of spinules, X 1.5. MCZ159.

Stereocidaris ingolfiana Mortensen:

3. 4, 5. Adapical, adoral, and side views, X 3.

6. Ambulacrum, ambital portion, X 6.

7. Interambulacrum, ambital portion, X 6.

8. Primary spine, X 1.5.

9. Close-up of the primary spine in figure 8 showing the features of the "wing," X 3.
NUMBER 40 67



Publication in Smithsonian Contributions to Zoology

Manuscripts for serial publications are accepted by the Smithsonian Institution Press, subject

to substantive review, only through departments of the various Smithsonian museums. NonSmithsonian authors should address inquiries to the appropriate department. If submission is

invited, the following format requirements of the Press will govern the preparation of copy.

(An instruction sheet for the preparation of illustrations is available from the Press on request.)

Copy must be typewritten, double-spaced, on one side of standard white bond paper, with

V/i" top and left margins, submitted in ribbon copy with a carbon or duplicate, and accompanied

by the original artwork. Duplicate copies of all material, including illustrations, should be retained

by the author. There may be several paragraphs to a page, but each page should begin with a new

paragraph. Number consecutively all pages, including title page, abstract, text, literature cited,

legends, and tables. The minimum length is 30 pages of typescript and illustrations.

The title should be complete and clear for easy indexing by abstracting services. Taxonomic

titles will carry a final line indicating the higher categories to which the taxon is referable:

"(Hymenoptera: Sphecidae)." Include an abstract as an introductory part of the text. Identify

the author on the first page of text with an unnumbered footnote that includes his professional

mailing address. A table of contents is optional. An index, if required, may be supplied by the

author when he returns page proof.

Two headings are used: (1) text heads (boldface in print) for major sections and chapters

and (2) paragraph sideheads (caps and small caps in print) for subdivisions. Further headings

may be worked out with the editor.

In taxonomic keys, number only the first item of each couplet; if there is only one couplet,

omit the number. For easy reference, number also the taxa and their corresponding headings

throughout the text; do not incorporate page references in the key.

In synonymy, use the short form (taxon, author, date, page) with a full reference at the end

of the paper under "Literature Cited." Begin each taxon at the left margin with subsequent lines

indented about three spaces. Within a taxon, use a period-dash (.—) to separate each reference.

Enclose with square brackets any annotation in or at the end of the taxon. For references within

the text, use the author-date system: "(Jones, 1910)" or "Jones (1910)." If the reference is

expanded, abbreviate the data: "Jones (1910, p. 122, pi. 20: fig. 1)."

Simple tabulations in the text (e.g., columns of data) may carry headings or not, but they

should not contain rules. Formal tables must be submitted as pages separate from the text, and

each table, no matter how large, should be pasted up as a single sheet of copy.

For measurements and weights, use the metric system instead of (or in addition to) the

English system.

Illustrations (line drawings, maps, photographs, shaded drawings) can be intermixed

throughout the printed text. They will be termed Figures and should be numbered consecutively;

however, if a group of figures is treated as a single figure, the individual components should be

indicated by lowercase italic letters on the illustration, in the legend, and in text references:

"Figure 9b." If illustrations (usually tone photographs) are printed separately from the text as

full pages on a different stock of paper, they will be termed Plates, and individual components

should be lettered (Plate 9b) but may be numbered (Plate 9: figure 2). Never combine the

numbering system of text illustrations with that of plate illustrations. Submit all legends on pages

separate from the text and not attached to the artwork.

In the bibliography (usually called "Literature Cited"), spell out book, journal, and article

titles, using initial caps with all words except minor terms such as "and, of, the." (For capitalization of titles in foreign languages, follow the national practice of each language.) Underscore

(for italics) book and journal titles. Use the colon-parentheses system for volume, number, and

page citations: "10(2) :5-9." Spell out such words as "figures" and "plates" (or "pages" when

used alone).

For free copies of his own paper, a Smithsonian author should indicate his requirements on

"Form 36" (submitted to the Press with the manuscript). A non-Smithsonian author will receive

50 free copies; order forms for quantities above this amount with instructions for payment will be

supplied when page proof is forwarded.