Paleozoic Gastropoda 

from the Moose River 

Synclinorium, Northern 

Maine 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 503-A 

Paleozoic Gastropoda 

from the Moose River 

Synclinorium, Northern 

Maine 

By ARTJiUR J. BOUCOT and ELLIS L. YOCHELSON 

CONTRIBUTIONS TO PALEONTOLOGY 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 503-A 

An investigation of fossils 

primarily of Devonian age 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1966 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

William T. Pecora, Director 

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

Washington, D.C. 20402- Price 30 cents (paper cover) 
CONTENTS 

Page 

Abstract __________________________________________ _ A1 Register of localities ___________________________ -- __ _ 

Introduction ______________________________________ _ 1 References cited __________________ ---- __ ------------

Occurrence and distribution of the gastropods _________ _ 3 Index ____________________________________________ _ 

Systematic paleontology ____________________________ _ 3 

ILLUSTRATIONS 

[Plates follow index] 

PLATE 1. Gastropoda and miscellaneous fossils 

2-3. Gastropoda Page 

FIGURE 1. Correlation table______________________ A2 

2. Sketch of "Euomphalopterus" _ _ _ _ _ _ _ _ _ _ _ _ 17 

TABLE 

Page 

A15 

17 

19 

Page 

TABLE 1. Distribution of gastropods in Paleozoic rocks of the Moose River synclinorium ________________ - ____ -- __ ------ A4 

III 

CONTRIBUTIONS TO PALEONTOLOGY 

PALEOZOIC GASTROPODA FROM THE MOOSE RIVER SYNCLINORIUM, NORTHERN MAINE 

By ARTHUR J. BoucoT and ELLIS L. Y OCHELSON 

.ABSTRACT 

Large-scale collecting in the middle Paleozoic strata of the 

Moose River synclinorium has yielded a few gastropods-one 

Ordovician species, six species from the Silurian, and two from 

rocks of Silurian or Devonian age, one of these also oceurring 

in rocks of undoubted Silurian age. The Devonian rocks 

yielded 17 species, one of which also occurs in the Silurian 

rocks, and by far the bulk of the specimens. 

The few specimens and their unsatisfactory state of preservation have resulted in use of open nomenclature for the most 

part. Eleven taxa are identified only to the generic level, and 

six are tentatively compared to previously named species. The 

generic assignment is questioned in four of the identified species ; in only one taxon is the generic and specific designation 

of common usage accepted without question. 

The new bellerophontacean subfamily Plectonotinae is diagnosed. Orossoceras is proposed as a new genus of Devonian 

age with 0. belandi, new species, as the type. The genus is 

placed within the Platyceratacea. Platyceras (Orthonychia) 

aroostookensis is proposed as a replacement name for P.? ( 0.) 

compressa Williams and Breger, 1916, not P. compressum Nettleroth, 1889. The occurrence of ophiuroid remains and "Nidulites," two faunal elements which do not fit conveniently into 

other faunal studies, is noted. 

INTRODUCTION 

This paper describes and illustrates gastropods obtained for the most part by Boucot during several years 

of field investigation in the Moose River synclinorium 

of northern Maine. Boucot ( 1961) has delineated the 

general stratigraphy of the area; Oliver (1960) has 

described the Early Devonian corals. With the exception of one pleurotomariacean gastropod, all specimens 

discussed are from rocks of Silurian and Devonian age. 

One new Silurian bellerophontacean is reserved for 

publication elsewhere by Boucot. Although John M, 

Clarke described specimens from this area in 1909, no 

other work has been done on these mollusks in the intervening years. 

In general aspect, the gastropod faunas resemble 

those of similar age known from the Appalachians, 

both to the north and to the south. Although the gastropods are of limited stratigraphic utility because of 

their rarity, occurrences support the correlation of rock 

units which has been determined from study of other 

fossil groups (chiefly brachipods and corals). 

Except where indicated, the taxonomic classification 

follows that published by Knight, Batten, and Y ochelson (1960). Specimens are rare and some are not well 

preserved; an open nomenclature has been used for 

most of the taxa. Future detailed study of middle 

Paleozoic gastropod faunas will undoubtedly increase 

the degree to which material can be identified, but because of limited present knowledge in this particular 

field, a conservative taxonomic approach is warranted. 

The morphologic terms used follow those given by Cox 

(1955). 

With the exeeption of a few specimens in limestone, 

the fossils occur in indurated, cleaved, slightly metamorphosed ( ehlorite zone) mudstone and siltstone. 

Most of the specimens were obtained by splitting slabs 

of matrix on a rock trimmer. These slabs were then 

soaked in hydrochloric acid and, after all shell material 

had been dissolved, latex rubber impressions were made 

from the internal and external molds. These impressions have been figured, though for a few species they 

have been supplemented by illustrations of the mold, 

or of the steinkern if it was not destroyed during preparation. The original specimens commonly are in several pieces. More than 8 tons of rock were split to obtain the specimens described herein. 

In addition to tlhe gastropods, the occurrence of N idulites and ophiuroid remains is noted. These uncommon 

fossils do not fit well with any of the major faunal 

studies, but it semns worthwhile to report their occurrence in Maine. 

The locality numbers and the register of localities are 

in the Silurian-Devonian (SD) catalog of the U.S. Geologieal Survey. A stratigraphic table prepared by 

Boueot (1961) is reproduced here as figure 1. All the 

formations mentioned in the text are shown in this figure except an unnamed conglomerate, an approximate 

equivalent of the Silurian Hardwood Mountain Formation, that occurs in the Attean quadrangle of northern 

Maine. 

A1 
A2 

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LOBSTER 

LAKE 

Seboomook 

Formation 

Lobster 

Lake 

Formation 

Volcanic 

rocks 

undifferentiated 

Sedimentary 

and volcanic 

rocks, undifferentiated 

WEST SIDE 

OF 

MOOSEHEAD 

LAKE 

Tomhegan 

Formation 

Tarratine 

Formation 

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Sedimentary 

and volcanic 

rocks, undifferentiated 

CONTRIBUTIONS TO PALEONTOLOGY 

DEER ISLAND 

AREA 

MOOSEHEAD 

LAKE 

Seboomook 

Formation 

Whisky 

Quartzite 

Capens 

Formation 

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Sedimentary 

and volcanic 

rocks, undifferentiated 

SPENCER 

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Parker Bog 

Formation 

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rocks, undifferentiated 

JIM POND 

Hobbstown 

Formation 

Hardwood 

Mountain 

Formation 

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and volcanic 

rocks, undifferentiated 

Basement 

complex 

BECK POND 

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Formation 

Basement 

complex 

ENCHANTED 

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Tomhegan 

Formation 

Tarratine 

Formation 

Seboomook 

Formation 

Basement 

complex 

LITTLE BIG 

WOOD POND 

Seboomook 

Formation 

Hardwood 

Mountain 

Formation 

Basement 

complex 

FIGURE !.-Correlation table of Paleozoic strata in the Moose River synclinorium of northern Maine (after Boucot, 

1961). 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A3 

OCCURRENCE AND DISTRIBUTION OF THE 

GASTROPODS 

Mollusks constitute but a sm~an fraction of the fossils 

collected from the Moose River synclinorium. At most 

localities brachiopods are the dominant faunal element; 

in some locali,ties corals are dmninant. Mollusks, the 

third most corrunon group, are mueh less abundant than 

either of these phyla,. Pelecypods and gastropods constitute virtually all of the mollusean fauna, the peleeypods being more emnmon than the gastropods. We 

estimate that there were about one thousand brachiopods collected for eaeh gastropod obtained. 

Among these few gastropod specimens, t:he pla.tyceratids are, by far, the most abundant; 1nembers of this 

family 'are"several times as abundant as all other gastropods combined. Among the remaining specimens, four 

grou ps--bellerophontaceans, pleurotmnariaeeans, all 

other archaeogastropods combined, and all high -spired 

gastropods combined-are subequal in abundance, pleurotomari'aceans being the most common of the four. So 

few specimens are involved, however, that the number 

of specimens within each group cannot be considered 

significant. The gastropods commonly do not appear 

to have been collected from former life assemblages; at 

a few localities there is fairly definite evidence that they 

were part of death ~assemblages. 

Some inferenees about the ecology of the platyceratids can be drawn. Most speeimens of the family were 

collected frmn localities in the Tarratine Formation 

where there is an indication that some were from former 

life assemblages. The Tarra:tine is divisible into three 

parts : a limestone lower member (McKem1ey Ponds 

Member), the main body of interbedded sub graywacke 

and slate, and an upper quartzite (Misery Quartzite 

Member) . Except for a few from the limestone, the 

pJatyeeratids were collected from the main part of the 

formation. In both parts of the formation the original 

matrix may have been a soft mud. 

In spite of the fact that platyeeratids are assumed to 

have lived on crinoid calyxes throughout their lives, 

none was found attached. Indeed, erinoid debris is rare 

in the subgraywacke and slate. This evidence is dearly 

not enough to abandon the traditional idea regarding 

the life habit of this group, but it does suggest that not 

all platyceratids were necessarily restricted at maturity 

to the substrate of a crinoid host. Other areas may 

yield information to reinforee the suggestion that some 

p]atyeeratids were free living in the adult stage. 

Not only platyceratids, but all other gastropod specimens are most common in the Tarratine Formation. 

The faunal distribution is summarized in table 1 ~of the 

22 Silurian and Devonian taxa identified, 10 oecur in 

the Tarratine. Curiously enough, the overlying Tomhegan Formation, which has been collected about onefourth as intensively as the Tarratine, has yielded fewer 

specimens but 11 taxa. Only three taxa are common 

to the two formations. The two formations thus contain the bulk of the taxa discussed in this paper. 

The Seboomook Formation, the lateral equivalent of 

the Tarratine, eontains only two species, both of whieh 

are common in the Tarratine. The slightly older Beck 

Pond Limestone has yielded only a few platyceratids. 

These are identified as PlatycerM ( Platyostoma) venf1'icosu/n1, the san1e species as in the younger beds, but 

that particular species category is admittedly broad. 

Less than a dozen specimens are known from the 

Silurian, but they are quite distinct from those of the 

Devonian. Euon1phalopterus, Poleu/nuita, and Or-iostmna are characteristic Silurian gastropods. 

SYSTEMATIC PALEONTOLOGY 1 

Class GASTROPODA 

Subclass PROSOBRANCHIA 

Order ARCHAE.OGASTROPODA 

Suborder BELLEROPHONTINA Ulrich and Scofield, 1897 

Superfamily BELLEROPHONTACEA M'Coy, 1851 

?Family SINUITIDAE Dall in Zittel-Eastman, 1913 

1Subfamily SINUITINAE Dall in Zittel-Eastman, 1913 

Genus PATELLOSTIUM Waagen, 1880 

Patellostium 1 revolvens (Williams and Breger) 

Plate 1, figures 1-4 

Bellet·ophmb (PatellosUum) revolvens Williams and Breger, 

1916,p.265,pl. 14, figs.14,15,20,27. 

Desc·ripti.on.-These shells are moderately large, are 

phaneromphalous, and have an explanate aperture. 

Early growth stages are unknown. Because the whorls 

expand at a rapid rate, few whorls are completed. The 

mature state is marked by an expansion of the aperture. 

The lip expands nearly equally in both lateral and anterior direetions. The aperture may have an extremely 

shallow sinus near the dorsum or may be straight, but 

neither a deep sinus nor a slit is present. The umbilici 

are narro·w but deep, their upper edges being steeply 

rounded. From the edges of the umbilicus, the profile 

is a low smooth curve not interrupted at the dorsum. 

Ornament is limited to obscure growth lines. 

Remarks.-This description is based on a restudy of 

'Villiams' and Breger's type lot from glacial drift, probablv derived from the Tarratine Formation at Detroit, 

So~erset County, supplemented by three additional 

speci1nens. One of the new speeimens is larger than 

any of the syntypes and shows a few of the growth lines. 

1 In the synonymies in this section, names of founders of species are 

given for the original reference, but, for brevity, are not repeated in 

subsequent citations to the same species. 
TABLE !.-Distribution of gastropods ,in Paleozoic rocks of the Moose River synclinorium 

Species 

ORDOVICIAN SILURIAN 

Kennebec,Unnamedl Hardwood 'Unnamed 

Forma- formation Mountain conglom- tion Formation erate 

SILURIAN 

or DEVONIAN 

Hobbstown Formation Beck 

Pond 

Limestone 

Seboomook 

Formation 

DEVONIAN 

Tarratine Formation Tom began Formation 

--,------1 I I I , •----

USGS Silurian-Devonian loc ___ ------------------------1 ~ 

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1---1--1--1 1-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-

Bellerophontacea: 

Pleurotomariacea: ~?~~~f(~:;~~=rr:~~~~;=--~~ =~m=---~ -~====~=~~ ==-~= -~~~~= m~-~-=~ ==:::~==:--- -=-~ == -m ==== ~~== ~~ == ~ ~ ~ ~ -= ~ ~ == ~= -__ ~ =~ ~- ~ ~ ~ ~ ~= ~ ~ ~ -_ ~ ~~~~~ Mourlonia cf. M.lucin!l (Hall) ______________________ -------------------------------- __________ ------------------ ____ ------------------ X X X-------- X---------- X------------------------

Bembexia? cf. B.? adjutor (Hall) _____________________ -------------------------- ______________________________________ ------------------------------------------------------------------ X--

~:~~~~~~~f~g~~~~!~~~-s~~======================== ----~---- ========== ====== ====== ========== ============== ==== ==== ==== ===~ ==== == == x == == == == == == == == == == == == == x == == == == == == == == == == == == Stenoloron cf. S. plena (IIall) ________________________ ---------- ________________________________ -------------- ________ ---- ---- ---- -- -- -- -- -- -- -- .-- -- -- -- -- -- -- -- -- __ -- -- -- -- -- -- -- -- ----X--

Euomphalopterus sp ________________________________ ---------- X ------ ------ ---------- -------------- ---- ---- ---- -· -- ---- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Platyceratacea: 

Microdomatacea: ~~~@!ff~H~rr::;~m~(~~H::-_=-=-= -_- ===m-~~~ -~-m~=-= ==~=== =-~-~~ ~~~~ ===== ~m--~==~~~-= :~ -~~ -~~= ~~~ ==~ ~ ~ ~ -~ == -- ~ == ~ ~ ~= ~ ~ -_ ~~ ~ ~ == == ~= ~ ~= =~ ~- ~ ~ ~~ ~[ Elasmonema cf. E. bellatulum (Hall) ________________ -------------------------------- __________ -------------- ________ ---- ____ ---- ____________________________________________________ X x, __ Oriostomatacea: 

Oriostoma SP---------------------------------------- ---------- X ------ ------ ---------- -------------- ---- ---- ---- ---- ---- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --·--

~!Y:~~U~t!~-~~~~~~-~~~--=========================== ========== ____ X____ X X --------------1----1---- I ----1----1----1--1--1--1--1--1--1 --o --o --o --o --o --o __ , --0--0 --o --0 --o --o --• --• --• --• --• __ , __ , --• --• --

Pseudophoracea: "Euomphalopterus" gasconensis Northrop ___________ ---------- ---------- ------ ------

Mu~~;~ri~~~i~: (Murchisonia) sp_-- ------------------- ---------- ---------- ------ ------~----------~--------------~----~----~----~----~----~--~--~--~--~=-~--~--~--~--~--~--~--~--~--~X~--~--~--~--~==~--~--~--~--~ X~--~ ==1 X~-- Lox~¥££~e1t~.s::;l~~~~~:-~~~~~~~~~~~-~-;~~~:--~~~ ~~~~~~~~~~ ~~~~~~~~~~ --~-- ~~~~~~ ~~~~~~~~~~ ~~~~~~~~~~~~~~ ~~~~ ~~~~ --~ ~~~~ ~~~~ ~~ ~ ~~ ~~ -~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ ~~ J~C ~~ -- ~~ ~~ ~~ ~~ ~~ ~ -- ~~~~ 

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PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A5 

The primary types, catalogued under USNM 59843, 

consist of five specimens. The original of Williams' 

and Breger's plate 14, figure 20, 'an external mold, is 

here designated lectotype and is reillustrated on our 

plate 1, figure 1. The steinkern illustrated by Williams 

and Breger as figure 15, the counterpart of figure 20, 

the steinkern illustrated as figure 14, and two fragments, 

are all designated paralectotypes; the original of their 

figure 27 is missing. Bellerophon plenus Billings, as 

figured by Clarke (1909, p. 153-154, pl. 17, figs. 27-28) 

from Gaspe, may be the same as this taxon. Clarke's 

material has not been investigated, and the illustrations, 

though suggestive of this interpretation, are not conclusive. 

The type species of Patellosthun was redescribed by 

Knight (1941, p. 236), who showed that it was a steinkern. Consequently, it is difficult to place the genus in 

any family, and in the last major revision of Paleozoic 

Gastropoda (!{night, Batten, and Y ochelson, 1960, p. 

I184), the genus was not assigned. The steinkern of 

Pa.tellostiu'm? revolrt-'ens closely resembles that of the 

type species, P. rnacrostoma (Roemer). If these species are congeneric, something more can be deduced of 

the characters of the genus. P.? revolven.s appears to 

have neither a slit nor a well-developed selenizone. 

Recent work by Radvan Horny (1962; 1963; oral 

eommun., 1962) has shown that several species from the 

Silurian and Devonian of Czechoslovakia are characterized by flaring apertures at maturity but that virtually 

no apertural reentrant is present in the flare. This new 

information suggests that the interpretation of Patellosthtm presented here is not anomalous. It suggests 

further that the genus may be related to Ptomati'l 

C1arke, 1899, and Oreni.striella Knight, 1945. There is 

every likelihood that these genera fonn a distinct subfamilial or familial group. Pending more detailed investigations, Patellostium is here placed questionably 

within the Sinuitidae. 

Occurrence.-Tarratine Formation: USGS loc. 270~SD, 

Brassua Lake quadrangle ; 272(}--oSD, Long Pond quadrangle; 

2890-SD, SpenceL' quadrangle. Tomhegan Formation: USGS 

loc. 2820-SD, Brassua Lake quadrangle. 

Figured spevimens.-USNlVI 59843, 126285. 

Subfamily BUCANELLINAE Koken, 1925 

Genus BUCANELLA Meek, 1871 

"Bucanella" brevilineatus (Conrad) 

Plate 1, figures 5, 6 

Belleroplwn brevilineatu8 Conrad, 1842, p. 269, pl. 16, fig. 6: 

Hall, 1879, p. 107, pl. 26, figs. 5-7. 

Tropi.docyclu8 brevilineatu.s, Clarke, 1908, p. 229, pl. 17, figs. 

7-16; Clarke, 1909, p. 139, pl. 32, figs. 4-7. 

Description.-A medium-sized compressed phaneromphalous bellerophontoid gastropod which has a prominent median lobe. The overall shape is compressed, 

but the 1nedian lobe of the shell is high and relatively 

wide, and has a well-rounded upper surface; its lateral 

slopes are steep. The upper surfaoe of the lateral lobes 

are strongly curved and turn rapidly into the flattened 

outer whorl faces. The umbilical shoulders are 

rounded, the umbilici are wide, and the umbilical sutures 

are sharp. Growth lines are prominent and are raised, 

though not sublamellose; the interspaces are about twice 

as wide as individual lines. The growth lineS are orthoeline within the umbilici and across the umbilical shoulders, then curve only slightly prosocline to the median 

lobe. The upper surface of the median lobe bears 

curved growth lines slightly finer and possibly more 

closely spaced than those on the lateral slopes. The 

relationship of the growth lines on the dorsum to those 

on the slope is not known. The ornamentation is confined to the coarse transverse collabral lines. 

Remarks.-Narrow trilobed bellerophontoids ornamented by prominent growth lines occur in strata of 

the Hamilton Group (Hall, 1879, p. 107, pl. 26, figs. 

5-7), the Gaspe Sandstone (Clarke, 1908, p. 229, pl. 17, 

figs. 7-16), and beds of late Early Devonian age at 

Highland Mills, Orange County, N.Y. In the past 

these bellerophontoids have been assigned to "Tropidocyclus bre,vilineat'ltS (Conrad)." The few specimens 

from the Tomhegan Formation in Somerset County, 

Maine, are also judged to be conspecifie. All citations 

in the synonymy are from the literature, and no comparison has been made of the Maine specimens with 

the types. 

For the past several decades, it has been customary 

to assign most trilobed middle Paleozoic bellerophontaceans to Bucanella. At the same time, it has been recognized informally that, fundamentally, these taxa probably have little in common with this genus except general shape. Bucanella nana, the type species of the 

genus, is from beds of Early Ordovician age. 

There is a distinct possibility either that the morphology of this form may be reinterpreted by other workers, or that better material may demonstrate conclusively a slit in the aperture of this species. In the past, 

the aperture always has been interpreted as sinuate. 

The supposition of a slit in the aperture parallels the 

findings presented below for Plectonot,ns. Were the 

presenee of a selenizone more strongly inferred, the 

writers would propose a new genus, but the available 

material does not yet warrant such a step. 

Occun·enoe.-Tomhegan Formation : USGS J.oc. 2750-SD, 2820-

SD, 2852-SD, Brassua Lake quadrangle. 

Figured specimen.-USNM 126369. 
A6 CONTRIBUTIONS TO PALEONTOLOGY 

Family BELLEROPHONTIDAE M'Coy, 1851 

Subfamily TROPIDODISCINAE Knight, 1956 

Genus GAMMADISCUS Horny, 1962 

Gammadiscus 1 somerseti (Williams and Breger) 

Plate 1, figures 7. 8 

Tropidodiscus ( Temnodiscus) somerseti Williams and Breger, 

1916,p.271-272,pl.14,fig.22. 

Description.-These shells are medium sized lanceolate phaneromphalous bellerophontaceans; growth lines 

form a narrow V-shaped sinus in the outer lip which 

does not give rise to a selenizone. The whorl profile is 

lanceolate, being angular at the dorsal crest, gently convex between the dorsum and the umbilical shoulders, 

and angulated at the umbici, with only the slightest 

rounding of· the shoulders. The sutures are distinct 

and give a stair-step umbilieal profile. The umbilici 

are moderately wide and occupy more than one-fourth 

of total width. The growth lines are closely spaced. 

They are normal to the umbilical angulations, but then 

curve smoothly to the posterior and rise until, at the 

dorsum, they make an angle of about 30° with the eenter 

of the crest. 

Rema.rks.-Williams and Breger (1916, p. 271-272) 

based Tropidodisctt8 ( Ternnodiscus) smnerseti on two 

steinkerns collected at Detroit, Somerset County, 

Maine; the two are catalogued under USNM 59852. 

Because the types show few eritical features, they are 

not reillustrated. The larger figured specimen is here 

designated leetotype, the smaller paralectot ype. Beds 

of Tarratine age are not known to crop out. in or near 

Detroit. Williams' and Breger's speeimens undoubtedly were collected from glacial drift. Brachiopods associated with the types elearly indicate that 

the matrix was derived originally from the Tarratine 

Formation. 

The description of Gamunwdi8cus? 8o1neneti given 

above is based almost entirely on several specimen~ colleoted from outcrops of the Tarratine Formation in 

Somerset County. The new material is eonsidered eonspecific. with the types; one of the specimens has the exterior preserved. and shows a sinuate periphery, rather 

than a slit as in Tropidodt~scu8. The generic description of Ganzmwdi8CU8 was published in a preliminary 

note (Horn}r, 1962) but was later given in detaiJ 

(Horny, 1963, p. 88). The type species is lanceolate 

in profile and has sinuate growth lines; \Villiams' and 

Breger's species is provisionally transferred to Ga.Jnrnodi8cus. Pending further information on the limits 

of the genus, the generic reference is here used questionably, inasmuch as the type of the genus is of Ordovieian age, and no other speeies have yet been assigned. 

The gap in reeord between the Ordovieian type anrl 

this Devonian oecurrenee suggests a need for eaution in 

the generic assignment. 

The speeimens identified by Williams and Breger 

(1916, p. 270-271) from the Chapman Sandstone in 

Aroostook County, Maine, as Tropidodi8cu.'3 obex 

Clarke differ from this species in being wider and expanding slightly less rapidly. The illustrations of the 

type (Clarke, 1907, p.193) are not outstanding, and from 

neither source is it possible to determine if this species 

has a sinuate periphery rather than a true apertural slit. 

T. curvilineatus (Conrad) has a similar lanceolate 

cross section but does have a narrow silt. So little is 

known about the presenee of a slit versus a sinus in the 

lanceolate Silurian and Devonian bellerophontaceans 

that meaningful eomparison cannot be m'ade with other 

species. 

Occurrence.-Tarratine Formation: USGS loc. 2705-SD, 2813~ 

SD, 2832-SD, Brassua Lake quadrangle; 2718-SD, 2719-SD, 

272(}.-.lSD, 3090-SD, Long Pond quadrangle; 2861~SD, Moose· 

head Lake quadrangle. 

Figured speoimens.-USNM 126282. 

Genus TROPIDODIS,CUS Meek and Worthen, 1866 

Tropidodiscus sp. 

Plate 1, figure 13 

Rmnarlc8.-A single specimen of Tr.opidodiscus was 

collected from a crinoidal limestone in the lower conglomerate member of the Hobbstown Formation. The 

specimen is a juvenile and is too immature to be assigned to any particular species. It differs from Gam.-

madiscu8? sonwrseti (Williams and Breger) in showing 

a selenizone on the crest. The crest is raised and flattened rather than steeply rounded. This speeies also 

appears to have slightly coarser growth lines which are 

more widely spaeed than in G. 80'mer8eti. 

Tropidodi._'iCU8 r·urvilinea.tu-8 (Conrad) is closely related but is distinct. That species has finer growth 

lines, a more inflated profile, and a less pronouneed crest 

upon whieh the selenizone is borne. 

The species cannot be compared with T. americanus, a 

species described by Williams and Breger (1916, p. 272) 

as T. 1n·inimus var. a.m.eriaanu8 and based on a single 

speeimen from the Chapman Sandstone in Aroostook 

County, Maine. That holotype is more than three times 

as large as .this form and is a steinkern. The steinkern 

sho,vs one detail of general interest in that the traee of 

the slit is preserved. The slit is more than one-fifth of 

the hody whorl circumference in depth. 

Occurrence.-Hobbstown Formation: USGS loc. 3479-SD, 

Spencer quadrangle. 

Fi-gured specimen.-USNM 126297. 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A7 

Subfamily PLECTONOTINAE, Boucot and Yochelson, 

new subfamily 

Dia.gnosi8.-Moderately large slit-bearing bellerophontid gastropods having a prominent raised median 

lobe that forms a trilobed cross section. 

Re1na/rks.-Smne of the speeimens from Maine, studied by Boucot in 1955, so strongly suggested that the 

aperture of this genus had ra slit that a east of the type 

species was reexamined. Study of this cast indicates 

that the V-shaped sinus described by Knight (19-!1, p. 

255-256) in the holotype might better be interpreted as 

an artificial break. Although Clarke suspected the 

presenee of a seienizone, his original material ·was too 

poor to demonstrate this point. The presence of a slit 

and a deep U-shaped sinus has been eonfirmed in speeimens from widely separated areas. In partieular, 

Boueot and Saul (in Saul, Boueot, and Finks, 1963, p. 

1048-10-!9) have described significant material frmn the 

Devonian of Ghana~ they also illustrated Maine and 

Gaspe. specimens showing a slit. Undeseribed material 

of Plectmwhts frmn Saudi Arabia and Antaretica also 

shows the slit and selenizone particularly well. 

Knight, Batten, and Y oehelson (1960, p. I175) had 

no knowledge of this slit, and they considered Plecf.onotits to be a subgenus of Bucanella. Beeause B1.wanellrt lacks a slit, the two generic. taxa were placed in 

the Sinuitidae, and in the subfamily Bueanellinae. 

This new finding necessitates the removal of Plectonotu-s to the Bellerophontidae. The subfamily Pleetonotinae is proposed here to include be1lerophontids having a trilobed eross section. Bon cot and Saul (in Saul, 

Boncot, and Finks, 1963, p. 10-!6-1047) indicated the 

need for this subfamily but did not formally propose it. 

This new interpretation will probably lead to the reelassification of several species of middle Paleozoic bellerophontaceans and may result in the establishment of 

new genera to be included in this subfamily. So far 

as is known, however, none of the described Bellerophontidae genera should be transferred to this subfamily. 

Genus PLECTONOTUS Clarke. 189'9 

Type species.-Plectonotu.s derby-i Clarke, 1899. 

De8cription.-A narrowly phaneromphalous, wide, 

bilaterally symmetrical gastropod having a trilobed 

whorl profile and a U-shaped sinus in the anterior lip 

which gives rise to a short but distinct slit. The median part of the whorl profile is raised, relativeiy broad, 

and only slightly arched; it slopes off sharply on each 

side. The lateral parts of the shell are narrower than 

the median lobe and curve sharply into the umbilicus. 

The umbilical sutures are sharply defined. A broad, 

raised flat selenizone, set off by two narrow revolving 

grooves, occupies the center of the dorsum. Ornamentation consists of very faint growth lines and rare spiral 

lira e. 

Remarks.-This redeseription of Plectonot1.JJ.S is based 

upon study of an impression of the holotype, a steinkern, of Plectonotus derbyi Clarke, 1899, from the 

Maecuru Group of Brazil, many specimens of Bellerophon (Plectonot1.us) trilobatus Sowerby, as figured and 

described by Williams and Breger, 1916, from the 

Chapman Sandstone of northern Maine, and specimens 

from the Tarratine Formation in Somerset County, 

Maine. 

As redefined, Plectonotu.s is confined to beds of Early 

and Middle Devonian age .. Species are known from 

Antarctica, Africa, Asia, North America, and South 

America; specimens from the Antarctic and Asia have 

been seen by the writers but are not described. The 

genus may occur in Europe, but specimens which clearly 

show the selenizone have not yet been described. The 

median lobe of Plectonotus is broad as contrasted with 

the median lobe of Bucanella. 

A s1naller but generally similar bellerophontacean is 

common in the Silurian of Maine but is distinguished 

by having prominent spirallirae; this new form is not 

described herein. Many of the Silurian specimens referred by Ameriean authors to B elleroplwn trilobatu.s 

Sowe.rby probably fall within the undescribed taxa. 

The enigmatic Tritonophon Opik from the Silurian 

of Australia is clearly distinguished from Plectonotus 

by its abundant spiral lirae. It is not evident, however, whether Tritonophon possesses a slit or simply 

an apertural sinus. 

In addition to the type, Plectonotus derbyi Clarke 

( 1899a, p. 70, pl. 3, figs. 14-17), three speeies are assigned to the genus. These are Plectonotus? salteri. 

Clarke ( 1899a, p. 71, pl. 3, figs. 12-13), also from the 

Devonian of Brazil; B ellerophon ( Plectonotru)'8?) gaspen.si8 Clarke (1907, p. 194) from Grand Greve, Gaspe 

peninsula; and B ellerophorn ( Plectonot'lt.s) fra.fu,rnu.s 

Reed described from the Devonian of South Africa and 

redescribed by Boucot and Saul (in Saul, Boucot, and 

Finks, 1963, p. 1048). Bucaniella trilobata var. 1,iram-u1ndo Clarke (1899, p. 37, pl. 2, figs. 20-22) is only 

questionably assigned. 

Finally, Planorbis trilobatus C;0nrad (1838, p. 113) 

may be a representative of this genus but is so poorly 

known that it definitely falls into the category of a 

no·rnen inqu:Z:rendum,. Though the species is obviously 

not a Planorbi.s, it is not evident that the species is 

better assigned to Plectonotus than to other bellerophontacean genera. The most practical course is to 

leave this name in the genus in which it was originally 1 placed to avoid ereating any secondary homonomy. 
A8 CONTRIBUTIONS TO PALEONTOLOGY 

Plectonotus cf. P. gaspensis (Clarke) 

Plate 1, figures 9, 10, 12, 14. 15 

BeZlerophon (Plect01wtus?) ua.spensis Clarke, 1907, p. 194, figs.; 

Clarke, 1908,p. 154,pl.17,figs. 17,18. 

Bellerophon (Plectonotu.s) trilobatus Sowerby, Williams and 

Breger, 1916, p. 266-269, pl. 14, figs. la, lb. 12. 13, 17-19, 28. 

Renwrks.-Williams and Breger (1916, p. 266-270) 

present an elaborate synonymy for the specimens which 

they identified as Bellerophon (Plectonotus) trZ:ZobatU8 

Sowerby. They included P. gaspens-is (Clarke) within 

Sowerby's species. Because this synonymy includes 

both Silurian and Devonian trilobed forms under the 

one specific name, the apparent limited stratigraphic 

range as shown by Plectonotus in the restricted sense 

is masked. Except for their specimens, the material 

referred to in their synonymy listing has not been investigated. Though it seems probable that several taxa 

have been confused under the name of Sowerby's species, it seems equally probable that the tangle cannot 

be unravelled without excellently preserved material. 

The illustrations provided by earlier authors are not 

particularly useful. 

It is a reasonable assumption that both the new material from Maine and the Devonian specimens described earlier by Williams and Breger belong to 

Clarke's species. The Maine specimens are steinkerns 

and, though they show the general characters well, they 

are not particularly informative as to the nature and 

individual variation of the specific characters. 

Occurrence.-Tarratine Formation : USGS loc. 2705-SD, 

Brassua Lake quadrangle; 2718-SD, 2719-SD, 2727-SD, 2783-

SD, Long Pond quadrangle; 2830-SD, Moosehead Lake quadrangle; 2813-SD, Pierce Pond quadrangle; 2729-SD, 3478-SD, 

Spencer quadrangle. Tomhegan Formation: USGS loc. 2819-

SD, Brassua Lake quadrangle. 

Figured specimens.-USNM 59843, 126290, 126370. 

Suborder PLEUROTOMARIINA Cox and Knight, 1960 

Superfamily PLEUROTOMARIACEA Swanson, 1840 

Family EOTOMARIIDAE Wenz, 1938 

Subfamily EOTOMARIINAE Wenz, 1938 

Tribe PTYC'HOMPHALIDE,S Wenz, 1938 

Genus MOURLONIA Koninck, 1883 

Mourlonia cf. M. lucina (Hall) 

Plate 2, figures 1-3 

Bttomphalus? t·otundus Hall. 1&!3, p. 172, fig. 4. 

Pleu1·otomaria ludna Hall, 1861/ p. 14; Hall, 1862, p. 42, pl. 5, 

fig. 12; Hall, 1876, pl. 18, figs. 5-11; Hall, 1879, p. 67, pl. 18, 

figs. 1-11. pl. 30, figs. 10. 11. 

Pleurotomaria r-otunda (Hall) not MUnster, Hall, 1876, pl 18, 

figs. 1-4. 

Botomaria. (Plcurodnw) lucina, Grabau and Shimer, 1909, p. 

645, fig. 8791C. 

M ourlonia lucin.a, Knight, 19-!4, p. 457, pl. 184, fig. 35. 

2 Listed in Hall's synonymies of 1876 and 1879, but seems to be in 

error inasmuch as this species name does not occur in the work cited. 

Description.-A low-spired rounded gastropod that 

has a selenizone on the periphery at midwhorl. The 

nucleus and the early whorls are unknown. The sutures 

are distinct, though not impressed. The body whorl 

embraces the penultimate whorl well below the selenizone. The ui)per surface is flattened near the suture but 

is not clearly set off and erosses an obscure angulation 

before it arches into the curved outer face. This curve 

is interrupted by the relatively wide peripheral selenizone. Below the selenizone, the profile is curved 

strongly inward to the curved base and then upward 

and inward, though it is not certain whether there is a 

narrow umbilieus. Growth lines are steeply prosocline 

and slightly curved above the selenizone, but they are 

almost orthoeline below. They are distinctly spaced, 

the distance between them being approximately the 

width of a lira. The selenizone is slightly raised and 

is flattened between the two revolving lira.e. Lunulae 

are more closely spaced than the growth lines. 

Remarks.-Although a few speeimens are available, 

most are incomplete or poorly preserved juveniles. The 

type of the species seems to possess spiral ornament that 

gives it a caneellate appearance unlike the Maine specimens; thus reference to the species can be only provisional. For both the typical representatives and the 

Maine specimens, there is some question whether the 

characteristics of the selenizone are truly those of 

111 mtrlonia. Pending further studies of Devonian gastropods, the generic concept is here used in an expanded 

manner. 

OccU1·rence.-Tarratine Formation: USGS loc. 2718--<SD, 2719-

SD, 2720-SD, 2766-SD, Long Pond quadrangle ; 2813-SD, Pierce 

Pond quadrangle. 

Figured specimen.-USNM 126288. 

Tribe EOTOMARIIDES Wenz, 1938 

Genus BEMBEXIA Oehlert, 1888 

Bembexia t cf. B.1 adjutor (Hall) 

Plate 2, figures 6-10 

Pleurotomaria adjutor Hall, 1879, pl. 21, fig. 16; pl. 30, fig. 1. 

Pleurotomaria (Lophospira) ad.jutor, Grabau, 1913, p. 354. 

Bembexia adjutor, Knight, 1944, p. 457, pl. 184, fig. 29. 

DescripUon.-A moderately low spired gastropod 

having a raised coneave-bordered selenizone on the outer 

whorl faee. Sutures are distinct, though not impressed. 

The body whorl embraces the penultimate whorl a slight 

clistanee below the selenizone. The upper whorl surface is inclined at about 80° from the horizontal continuing st11aight to a spiral lira at its outer edge. Below this lira the profile is slightly eoncave and nearly 

vertical to another lira, this one marking the upper 

edge of the peripheral selenizone. The lower edge of 

the selenizone is also strongly bordered, below which the 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A9 

outer whorl face is nearly vertical for a short distance 

to a slightly finer lira that is embraced except on the 

body whorl. Below this fourth lira, the outer face 

continues nearly vertical for a short distance, but then 

curves abruptly into the flattened base. The base may 

be narrowly phaneromphalous, but this detail is not 

known with certainty. The inner lip is slightly reflexed. 

The selenizone is strongly bordered, raised well above 

the general surface of the outer whorl face, distinctly 

concave, and ornamented with nearly straight, closely 

spaced lunulae having a finer texture than that of the 

growth Jines. Growth lines are straight and are prosocline on the upper surface, but bend to more strongly 

prosocline just above the selenizone. Their course below the selenizone is unknown; they appear to be 

straight, opisthocline on the base. They are widely 

spaced and coarsely lirate; the interspaces are about five 

times as wide as the lines. Ornament consists of the 

four spiral threads and the colabrallira. 

Rernark8.-The description above is based on four 

juvenile specimens. Several are distorted but, as near 

as can be determined, all are conspecific. The illustrations of Pleurotomaria adjutor Hall suggest characters 

closely similar to, and possibly identical with, the taxon 

described above. No authentic specimens of that species are available for comparison, and it seems wiser to 

delay definite identification until a comparison can be 

made with the Maine specimens. 

The elaborate ornament of this species is certainly 

not characteristic of the genus Bembewia; the species 

may be the representative of a new genus. BembeXJia 

has been used for other elaborately ornamented species, 

however, for example, B. ellenae Conklin, from the 

Mississippian New Providence Sihale. With the material now available, no particular purpose is gained in 

naming a new genus, and the expanded use of B embewia 

will be continued. 

Occurrence.-Tarran.tiue Formation: USGS loc. 2705-SD, 

Brassua Lake quadrangle. 

Figured specimens.-USNM 126280, 126293, 126371. 

Family LOPHOSPIRIDAE Wenz, 1938 

Subfamily LOPHOSPIRINAE Wenz, 1938 

Genus LOXOPLOCUS Fischer, 1885 

Subgenus LOPHOSPIRA Whitfield, 1886 

Loxoplocus (Lophospira) sp. 

Plate 2, figures 4, 5 

Remarks.-Only two gastropods were obtained during the field investigation from rocks of Ordovician 

age. Both are moderately high spired and have an 

angulate periphery. The upper whorl surface is flattened and inclined downward. The angulation a;t the 

prominent carinate ·periphery is the most striking feature of the profile. A second angulation is at the point 

7'95-886 0-66-2 

of the juncture of the penultimaJte whorl and is covered 

except on the body whorl. The sutures are distinct but 

not impressed, and the surfaces between the angulations 

are little arched. Remnants of growth lines 1are preserved only near the umbilical region ; the umbilicus 

is possibly anomphalous. The nature of the aperture 

is not known, but the presence of a selenizone at the 

peripheral angulation is a likely possibility. In spite 

of the paucity of detail, there is little question as to the 

generic affinities of this form, though, of course, specific 

identifiCJation is impossible. 

Occurrence.-Kennebec Formation: USGS loc. 4317-00, Brassua Lake quadrangle. 

Figured specimens.-USNM 126277, 126281. 

Subfamily RUEDEMANNIINAE Knight, 1956 

Genus RUEDEM:ANNIA Foerste, 1914 

R uedemannia? sp. 

Plate 2, figures 20, 21, 24, 25 

Re11Ulrks.-A medium -sized turbiniform gastropod is 

known from three external molds. The sutures are distinct, and the body whorl embraces about the mid whorl. 

The upper whorl surface is steep and sigmoidal in section, being curved outward at its lower edge. The juncture of outer and basal whorl face is marked by a wide, 

raised and lightly rounded band. Even though growth 

lines cannot be observed, there is every likelihood that 

this band is a selenizone. The outer whorl face is concave from below the presumed selenizone to midwhorl, 

below which it becomes convex but gradually curves inward. Growth lines are prosocline, sweeping strongly 

backwards on the upper surface; their course on the 

outer whorl face is unknown. Ornament is confined 

to the fairly fine, closely spaced growth lines. 

The specimens possess the general shell form crharacteristic of Ruedemannia though they lack spiral ornament near the selenizone. The poor preservation, the 

small amount of material, and, above all, the lack of 

recent studies of Devonian pleurotomariacean gastropods prevent positive identifie31tion on both the specific 

and generic levels 

Occurrence.-Tarratine Formation: USGS loc. 2705-SD Brassua Lake quadrangle ; 2813-SD, Pierce Pond quadrangle. 

Figured sp·ecimen.s.-USNM 126278, 126368. 

Family GOSSELETINIDAE Wenz, 1938 

Subfamily GOSSELETININAE Wenz, 1938 

Genus STENOLORON Oehlert, 1888 

Stenoloron cf. S. plena (Hall) 

Plate 1, figure 11 

Plettrotoma,ria plena Hall, 1876, pl. 17, figs. 11-13; Hall, 1879, 

p. 66, pl. 17, figs. 11-13. 

Description.-A medium-sized, phane~omphalous, 

rotelliform gastropod possessing a narrow selenizone 
AlO CONTRIBUTIONS TO PALEONTOLOGY 

on the upper half of the whorl just above the periphery. 

The nucleus is not known, but probably is orthostrophic; sutures are distinct, though not impressed. 

The upper whorl surface profile is flattened to near its 

outer limit where it curves smoothly into the outer whorl 

face, which apparently is moderately well rounded. 

The body whorl embraces the penultima.te whorl at the 

periphery, a short distance below the selenizone. The 

base is rounded and narrowly phaneromphalous. 

Growth lines are straight; they are prosocline above 

the selenizone and opisthocline below, ·arched only for 

an ·extremely short distance just below the selenizone. 

The lines are closely spaced, interspaces being only 

three to four times tJhe width of the lines; they are distinctly raised, though not sublamellose. The selenizone 

is above the periphery; it is narrow, depressed, and distinctly concave. The lunulae of the selenizone are more 

closely spaced than are the growth lines. 

Remarks.-Only one distorted specimen of this taxon 

was found in Maine. It closely resembles Pleurotomaria plena Hall, 1876, from the Onondaga Limestone 

of Albany County, N.Y. No specimens of Hall's species 

are available for comparison, but his illustrations show 

the Maine form to be identical in nearly all respects, 

except that the selenizone of the type is apparently 

somewhat wider than that of the Maine specimen. Until the amount of individual variation in this fea;ture is 

better known, only a comparison can be made with 

Hall's species. 

Occurrence.-Tomhegan Formation: USGS loc. 2820--SD, 

Brassua Lake quadrangle. 

Figured specimen.-USNM 126307. 

Family EUOMPHALOPTERIDAE Koken, 1896 

Genus EUOMPHALOPTERUS Roemer, 1876 

Euomphalopterus sp. 

Plate 1, figure 18 

Remarks.-Half a dozen specimens have been found 

which possess the prominent marginal frill, moderately phaneromphalous umbilicus, and trochoid shape 

of Euomphalopterus. The material is inadequate for 

~pecific identification, but seems to be more similar in 

overall shape and size of umbilical region to the type 

species, E. alatus Wahlenburg, common in the Silurian 

of northern Europe, than it does to E. valeria (Billings), a species common in the Guelph faunal zone. 

Both species have been report~d from Gaspe. 

Occurrence.-Hornfels of late Llandovery age : TTSGS loc. 

3475-SD, Stratton quadrangle. 

Figured specimen.-VSNM 126274. 

Suborder TROCHINA Cox and Knight, 1960 

Superfamily PLATYCERATACEA Hall, 1859 

Family HOLOPEIDAE Wenz, 1938 

Genus HOLOPEA Hall, 1847 

Holopea sp. 

Plate 3, figure 16 

Remarks.-This identification of H olopea sp. is 

based on a single broken external mold. The shell is 

globose and low spired. This form may have had a 

narrowly phaneromphalous umbilicus. Growth lines 

are straight and nearly orthocline. Though the specimen is well preserved, its species cannot be identified 

because it is incomplete. It be~rs some resemblance 

to the form from Gaspe identified by Clarke (1908, 

p. 148) as H olopea cf. antiqua ( Vanuxem). 

Occurrence.-Tomhegan Formation: USGS" loc. 2820--SD, 

Brassua Lake quadrangle. 

Figured specimen.-USNM 126284. 

Family PLATYCERATIDAE Hall, 1859 

Genus PLATYCERAS Conrad, 1840 

Subgenus PLATYCERAS Conrad, 1840 

Platyceras (Platycerast) sp. 

Plate 3, figures 17, 19, 20, 25 

Remarks.-A medium-sized gastropod, probably having only the first whorl in contact, is represented by 

three somewhat distorted specimens. The form of the 

apical whorl is not known with certainty, though it 

probably is globose. Because the uncoiled body whorl 

is eompressed, the cross seetion is almost rectangular in 

outline rather than ellipsoidal. The shell is nearly bilaterally symmetrical, the early whorls appearing to be 

sunk below the level of the upper whorl surface. The 

mature outer whorl face is flattened, horizontal for 

much of the distance; it then drops outward and downward to the periphery and the whorl cross section is 

therefore almost triangular. The basal surface of the 

whorl is flattened and produced gently upwards from 

the fairly sharp periphery to the shallow umbilicus. 

The ornament is limited to transverse growth lines 

which are apparent only in the region of the aperture. 

The compressed shape of the shell and the apparent 

closed coil of the earliest whorl removes this form from 

close association with the subgenus Orthonychia. The 

subtriangular cross section is most uncommon, and it is a 

question whether the specimens are properly referred 

to Platyceras. The most similar described species are 

Platyceras compre8sum N ettleroth, from the Devonian 

of the Falls of the Ohio River, and P. carimatum Hall, 

from the Devonian of New York State. The Maine 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE All 

material is too incomplete for a close comparison with 

either. Further speculation as to the placement of 

these three species must be delayed until better material 

is available. 

Occurrence.-Tomhegan Formation : USGS loc. 2750-SD, 

2820-SD, Brassua Lake quadrangle. 

Figured specimen8.-USNM 126296,126305, 126306. 

Subgenus PLATYOSTOMA Conrad, 1842 

Platyceras (Platyostoma) ventricosum (Conrad) 

Plate 3, figures 18, 21, 22 

Platyostoma ventricos1tm Conrad, 1842, p. 275, pl. 17, fig. 5 ; 

Williams and Breger, 1916, p. 262-263, pl. 13, fig. ?15, 18 

(these authors cite numerous earlier references in their 

synonymy which is not repeated here) ; Knight, 1941, p. 

253-254,pl.85,figs.3a-d. 

Platyceras ventricosnm, Nettleroth, 1889, p. 168, pl. 25, fig. 10. 

Platyceras (Platyostoma) ventricosum, Knight, 1944, p. 473, 

pl. 193, figs. 3-4; Knight, Batten, and Yochelson, 1960, p. 

1240, fig. 153-13. 

Remarks.-Although this species is the most abundant one in the collections, none of the Maine specimens 

of Platyceras ( Platyost01na) ventricosum are particularly well preserved. Insofar as they ·are preserved, 

they agree in all respects with the redescription and 

reillustration of the type of this species (Knight 1941, 

p. 253-254). 

Williams' and Breger's specimens also are distorted. 

All references in the synonymy given by them (Williams and Breger, 1916, p. 262) could not be checked, 

but the probability is great that the references all apply 

to the same general sort of large, rapidly expanding 

low -spired globose shells. This specific name has been 

used for years as a "dumping ground," but although 

good specimens of this species are rare, there is no 

reason to believe that strikingly different material has 

ever been assigned to this taxon. The species eoncept 

used for this form probably approximates the eoncept 

of a Recent species almost as well as any other paleontologie speeies for which excellently preserved specimens are not available. 

No speeimens were found attached to crinoid calyxes. 

In spite of the presumed coprophagous life habitat of 

this gastropod on crinoid calyxes, crinoidal debris is 

rare in the beds from which most specimens were 

obtained. 

Occurrence.-Beck Pond Limestone: USGS loc. 3499-SD, 

3500--SD, Spencer quadrangle. Seboomook Formation: USGS 

loc. 2879-SD, 3481-SD, Brassua Lake quadrangle. Tarratine 

Formation: USGS loc. 2700-SD, 2701-SD, 2705-SD, Brassua 

Lake quadrangle; 2721-SD, 2731-SD, Long Pond quadrangle; 

2767-SD, 2771-SD, 2813-SD, 2872-SD, Pierce Pond quadrangle; 

2729-SD, Spencer quadrangle. Tomhegan Formation: USGS 

loc. 2713-SD, Brassua Lake quadrangle. 

Figured specimens.-USNM 126294, 126300, 126308. 

Subgenus ORTHONYCHIA Hall, 1843 

Platyceras (Orthonychia) sp. 

Plate 3, figures 23, 24 

Rernar·ks.-One speci1nen of a large cornueopia-hornshaped uncoiled gastropod was found. The ornamentation is limited to sinuate growth lines paralleling the 

irregular aperture. The earliest growth stages are not 

preserved. 

Many species of this subgenus have been described. 

~'"illiams and Breger (1916) deseribed three species 

from Maine, in one of which they distinguished two 

varieties. Each form is based on a single small speeimen; none appear to be closely related to this species. 

In detail, Platycera8 (Orthonychia) compre88a Williams and Breger is flattened, P. (Orthonychia) aroostooki Williams and Breger is not twisted, and P. 

(Orthonychia) hebes (Clarke) as reeognized by these 

two authors, and including the two varieties they distinguish, is a low, rapidly expanding cone. 

The speeies figured has more in eommon with sueh 

na1ned Devonian taxa as Platycera.'3 (Orthonychia) 

dentaltum (Hall),P. (0.) tortUAo8a (Hall) andP. (0.) 

spirale (Hall), all of which were deseribed originally 

from Helderberg or Oriskany strata of New York. All 

have in common a rapidly expanding shell which is 

clearly an open eoil twisted in three dimensions. The 

superficially similar P. milleri Nettleroth, from the 

Devonian of the Falls of the Ohio River, bears nume,rous large spines and almost eertainly represents another 

stock. 

These three named forms and the single Maine specimen might be distinguished as a subgenus distinet from 

Orthonychia" However, until sufficiently large populations of eaeh species are available to permit some basis 

for judging the amount of individual variation in what 

is clearly a highly variable group, any revision of the 

platyceratids should be deferred. 

During this investigation, it was noted that Platyceras 

(Orthonych-ia) cornpressa Williams and Breger is a 

junior homonym of P. cmnpressum N ettleroth, 1889 

( p. 162, pl. 25, figs. 8, 9), from the Devonian strata 

exposed at the Falls of the Ohio River. The types of 

both forms have been examined, and there is no question 

that they are distinet. Therefore, the name Platycera.s 

(Orthonychia) ar~oostooken8is is proposed as a replacement name for P. (Orthonychia) compres8a Williams 

and Breger. 

Occurren.ce.-Tarratine Formation: USGS loe. 2813-S>D. 

Pierce Pond quadrangle. 

Figured speclmen.-USNM 126292. 

Genus CROSSOCERAS Boucot and Yochelson, n. gen. 

Type 8pecies.-Orossocer·as belandi Boueot and 

Y ochelson, n. sp. 
A12 CONTRIBUTIONS TO PALEONTOLOGY 

Diagnosis.-Flattened, rapidly expanding platyceratid gastropods ornamented with revolving striations 

and widely spaced growth lines that extend as transverse frills; apical whorl in contact; body whorl open 

coiled. 

Discussion.-This new genus has a shape similar to 

Platyceras ( Platyostoma) but that form lacks the prominent transverse frills. No reason for the periodic expansion of the aperture in this genus is apparent. 

In addition to the type, only one other species is assigned to Orossoceras. This is Platyceras newberryi 

Hall (1859, p. 333-334, pl. 63, figs. 14 a-c). 

Crossoceras belandi Boucot and Yochelson, n. sp. 

Plate 3, figures 6-15 

Description.-A medium-sized, closely coiled hornshaped gastropod of 11h or more whorls. The nucleus 

and the first whorl are coiled discoidaily and are in 

contact, whereas the later whorls are free. The aperture expands rapidly. The outer lip is steeply prosocline in all growth stages, but is slightly irregular. 

The expansion of the whorl is not uniform, being restricted by growth ridges. The upper surface remains 

subdiscoidal at all growth stages, and most expansion 

is below midwhorl. Atop each growth ridge, a central 

growth line is expanded into an elaborate frill. Almost 

every fill is irregularly fluted or c.renulated. The 

frills have their maximum width on the outer whorl 

face and diminish in size toward the umbilicus; the umbilical region itself is free of frills. Other ornamentation consists of fine revolving striations. Grooves on 

the interior of the shell are the internal reflections of 

the low rounded transverse ridges upon which the frills 

are located. 

Remarks.-Oros8,oceras belarndi is related to 0. new'-

berryi (Hall), but can be distinguished from that species by its more rapidly expanding aperture and its 

smaller degree of open coiling. Other described globose 

platyceratids lack the impressive ornaments of this 

species. 

The species is based on five silicified specimens from 

near Glenerie, N.Y., supplemented by three specimens 

from Somerset County, Maine. The Glen erie material 

is beautifully silicified, but the Maine specimens are 

less well-preserved steinkerns and external molds, 

which, however, show enough detail to permit certain 

identification with the first group. Most of the type lot 

'vas collected from the Glenerie Limestone of Chadwick (1908) along New York Highway 9W, 1 mile 

north of Glenerie and 1 mile south of Cockburn, N.Y. 

The species is named for Dr. Jacques Beland, Department of Geology, University of Montreal, who also 

found specimens of this species in the lower part of the 

Grand Greve Limestone. That locality is 500 feet south 

of the Petite N eigette River near the boundary of lots 

43 and 44 and the boundary of ranges III and IV of 

Neigette Township, Rimouski County, Quebec; the approximate latitude is 48°22' N. and the approximate 

longitude 68°22' W. (written commun., J. Beland, 

1963). 

Holotype.-VSNM 126283E. Paratypes USNM 126283A126283D, 126286A-126286C. 

Occurrence.-Tarratine Formation: USGS loc. 2767-'SD, 

Moosehead Lake quadrangle. 

Figured specimens.-VSNM 126283A, 12628310, 126283E, 

126286A. 

Superfamily M:ICRODOM:ATACEA Wenz, 1938 

Family ELASM:ONEM:ATIDAE Knight, 1956 

Genus ELASM:ONEM:A Fischer, 1885 

Elasmonema cf. E. bellatulum (Hall) 

Plate 3, figures 1-5 

Lomonema bellatulum Hall, 1861, p. 104; Hall, 1862, pl. 4, figs. 

4, 5. 

Loxonema (I8'onema) bellatula, Hall and Whitfield, 1872, p. 200 

(list only) . 

I sonema bellatu.Za, Meek and Worthen, 1865, p. 252; Meek and 

Worthen, 1868, p. 443 ; Hall and Whitfield, 1875, pl. 13, fig. 

12; Hall, 1876, pl.14, figs. 10-15. 

Callonema bellatulum, Hall, 1879, p. 51, pl. 14, figs. 10-15, pl. 28, 

figs. 18, 19 ; N ettleroth, 1889, p. 175, pl. 20, figs. 4-7 ; Kindle, 

1901, p. 698; Grabau and Shimer, 1909, p. 692, fig. 986; 

Stauffer, 1911, pl. 10, fig. 10; Grabau, 1913, p. 358; Hubbard 

and others, 1915, p. 5, Illus. sheet II, fig. 38. 

Callonema cf. bellatulum, Clarke, 1908, p. 299, pl. 15, fig. 8. 

Ela8'monema bellatulum, Knight, 1941, p. 110, pl. 52, figs. 5a-c ; 

Knight, 1944, p. 469, pl. 192, fig. 24; Knight, Batten, and 

Yochelson, 1960, p. 1243, fig. 155--3. 

Rernarks.-Some half dozen specimens in the collection agree with the redescription and reillustration of 

this species given by Knight (1941, p. 110). One of the 

best specimens available has the inner lip and the immediately adjacent basal area preserved. This speci-

·men has an indentation in the area of the columella and, 

presumably, is minutely phaneromphalous. Knight's 

illustrations indicate that the type of the species is narrowly phaneromphalous. None of the type lot or topotypieal specimens are available for comparison. Until 

the individual variation in the width of .the umbilicus 

is better known, the Maine material can be only tentatively referred to the species. There is considerable 

variation among the Maine specimens, particularly in 

the shape of the whorls, but this variation is all attributed to deformation by diagenetic and postdiagenetic 

events. 

Oocun·ence.-Tomhegan Formation: USGS loc. 2819---SD, 

2820-SD, Brassua Lake quadrangle. 

Figured 8pecimens.-USNM 126302, 126303, 126316. 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A13 

Superfamily ORIOSTOMATACEA Wenz, 1938 

Family ORIOSTOMATIDAE Wenz, 1938 

Genus ORIOSTOMA Munier-Chalmas, 1876 

Oriostoma sp. 

Plate 2, figures 18, 22 

Rema.rks.-Three specimens, a, steinkern, a flattened 

external mold of the upper whorl surface of a, mature 

specimen, and an external mold of the outer whorl face 

of a juvenile specimen, indicate the presence of Oriostoma in the Moose River area of northern Maine. The 

material is inadequate for anything more than generic 

identification. 

The specimens are low spired and have a distinct, 

slightly inclined upper whorl surface. Three spiral 

cords, the most prominent of which is just below the 

suture, ornament this surface. The outer whorl face 

is steeply inclined above the periphery and nearly vertical below this point; the periphery is at or below the 

midwhorl. This surface is ornamented by five spiral 

cords. The basal surface and umbilical features are 

unknown. Growth lines are distinct and sublamellose; 

they are prosocline on the upper surface and nearly 

orthocline on the outer whorl face. 

Other Oriostoma occur in Maine. In the U.S. N ationa! Museum collection are specimens from the Silurian of Whiting Bay and Field Point, Edmonds Township, Washington County, Maine. These specimens 

were generically identified and named in manuscript by 

H. S. Williams, but descriptions were never published. 

The specimens are larger and have more closely spaced 

growth lines; they may represent another species. 

Occurrence.-Hornfels of late Llandovery age: USGS loc. 

347~SD, Stratton quadrangle. 

Figured specimens.- USNM 126314, 126315. 

Oriostomatid operculum 

Plate 2, figure 23 

Remarks.- The impression of one multispiral operculum is available. Only the outer surface is preserved, 

but this surface shows the operculum to be a low cone. 

Sutures are distinotly incised. The individual whorls 

are wide for a multispiral operculum. The specimen 

cannot be referred to any particular species of Oriostoma. 

One specimen in the collections of the U.S. National 

Museum was identified by H. S. Williams as the operculum of a gastropod. This specimen, from the Silurian at Whiting Bay, Edmonds Township, ·washington 

County, Maine, appears to be identical with the form 

noted here. Other opercula from Burnt Cove in the 

same township clearly represent another specres or 

genus. 

Occurrence.-Hardwood Mountain Fonnation: USGS loc. 

3469-SD, Spencer quadrangle. 

Figured specimen.-USNM 126312. 

Genus POLEUMITA Clarke and Ruedemann, 1903 

Poleumita sp. 

Plate 2, figures 17, 19 

Remarks.-Several Silurian gastropods are suggestive of Poleumita, but the specimens are too fragmentary for identification to species level. The best specimens are so low spired as to be nearly planispiral. The 

growth lines are steeply prosocline and are foliaceous; 

they form incipient spines at four places on the upper 

and outer whorl face. Other ornament consists of seven 

or more spirallirae on the outer whorl face and rat least 

four lirae on the upper whorl face, only one of which is 

prominent. No information is available on the possible 

presence of septa in juvenile stages. 

Poleumita is here placed close to Oriostoma rather 

than with the Euomphalacea (Knight, Batten, and 

Y ochelson, 1960). This genus may not have had an 

outer calcitic shell and henoo should not be placed in 

that superfamily. The evidence for neither placement 

is strong. 

Occurrence.- Hornfels of late Llandovery age: USGS loc. 

3475-SD, Stratton quadrangle, 3483- SD, Spencer quadrangle. 

Figured 8pecimen.-USNM 126279. 

Suborder UNCERTAIN 

Superfamily PSEUDOPHORACEA Miller, 1889 

Family PSEUDOPHORIDAE Miller, 1889 

"Euomphalopterus" gasconensis Northrop 

Plate 1, figures 19, 21, 22; text figure 2 

Euomphalopterus ga.sconen8is Northrop, 1939, p. 212, pl. 22, figs. 

3, 4 ; '!variety p. 212, pl. 23, fig. 4. 

Remarks.- The two available specimens do not particularly add ·to the original species description. The 

first specimen is a crushed fragment of about one-third 

of two whorls which originally had a trochiform outline. These whorls show peripheral scooplike spines 

and prosocline growth lines. The base of the shell, as 

judged from the intA:lrnal impressions, was ornamented 

with transverse growth lines of about the same weight 

as those on the upper surface of the whorl (fig. 2). 

In this respect the specimen differs from the holotype, 

but this difference is not considered significant. The 

second specimen is a small fragment that only shows 

the peripheral spines. 

This species is generically distinct from any previously described form, but the available mawrial is too poor 

to form tJhe basis for satisfactory description of a new 

genus. The holotype, with which the Maine specimens 

have been compared, is partly buried in a hard mUJtrix 

and cannot be prepared easily for future study. 

Trochus astraliformis Lindstrom, 1881, from the Silurian of Gotland, is probably congeneric with "Euomphalopteru-s" gasconensis. The Gotland species has 

coarse oollabral ornament on its base. The spines of 
A14 CONTRIBUTIONS TO PALE ONTOLOGY 

FIGURE 2.- Artist's rendering of "Euornphalopterus" gasconensis 

Northrop, shown with part of the shell removed to reveal the 

growth lines on the basal surface. 

that species extend out at an angle from the whorl, 

whereas in "E." ga8conensis the spines appear to be subparallel to the whorl surface. 

Williams and Breger (1916, p. 278) described two 

Devonian species from the Chapman Sandstone as Pseudotectus, which may be an allied genus. Neither of their 

species has anything in common with this species. 

Occurrence.- Hobbstown Formation: USGS loc. 3479-SD; 

Spencer quadrangle. Unnamed conglomerate: USGS Joe. 5995-

SD, Attean quadrangle. 

F i gu1·ed specirnens.-USNM 126316, 144479. 

Order 7ARCHAEOGASTR0l'ODA 

Suborder MURCHISONIINA Cox and Knight, 1960 

Superfamily MURCHISONIACEA Koken, 1896 

Family MURCHISONIIDAE Koken, 1896 

Genus MURCHISONIA Archiac and Verneuil, 1841 

Subgenus MURCHISONIA Archiac and Verneuil, 1841 

Murchisonia (Murchisonia) sp. 

Plate 2, figures 11, 12 

Description.-A high-spired gastropod having a concave selenizone on the periphery bounded by revolving 

carinae. Sutures are distinct but not impressed. The 

whorl profile is flattened from the suture to a revolving 

carina near midwhorl. A lower carina is parallel with 

the upper one; both border the selenizone and are peripheral. The whorl face below the selenizone proceeds steeply downward for only a short distance to the 

next suture. The selenizone is distinctly concave between the bordering carinae and apparently is smooth. 

The growth lines are steeply prosocline above the upper 

carina and are unknown below. Other ornament is 

lacking. The base and umbilical condition are unknown, as are all details of the aperture. 

Remarks.-Th'ree specimens are available, though 

only one shows much detail. The single specimen upon 

which most of the above description is based, although 

moderately well preserved, is too incomplete to be compared in detail with any of the named species of Devonian M urchisonia. 

The species named Goniostropha chapm.ani by Williams and Breger (1916, p. 276) is based on a steinkern. 

Details of the selenizone and whorl profile cannot be 

compared. That species is probably not conspecific, 

for it seems to be higher and wider than this species. 

Occurrence.-Tarratine Formation: USGS loc. 2798--SD, 

Pierce Pond quadrangle. Tomhegan Formation: USGS loc. 

2713-SD, 2820-SD, Brassua Lake quadrangle. 

Figured specirnen.-USNM 126299. 

Murchisonia (Murchisonia?) sp. 

Plate 2, figure 13 

Remarks.- High-spired specimens from several localities and horizons may be referred to Murchisonia. 

All specimens are slightly to badly distorted; the figured one is the best preserved. The whorl profile is 

more swollen at the periphery and has the periphery 

higher on the whorl than in the previous species. The 

selenizone is lower and is less prominent. As a result 

of the inflated whorl profile and the obscure selenizone, 

the shells superficially resemble Loxonema. One or 

two poorly preserved Maine specimens of that genus 

may have been confused with Murchisonia. In fact, 

whether this form occurs in the two formations listed 

or whether material is being combined under one name 

merely because it is all poorly preserved is an open 

question. 

It is unlikely that this taxon is actually the same as 

Goniostropha chapmani Williams and Breger, although 

both forms have features in common. Their species 

may be somewhat more angular at the periphery, but 

the fact that the single known specimen is a steinkern, 

makes precise comparison impossible. 

Occurrence.-Hardwood Mountain Formation: USGS loc. 

3469-SD, Spencer quadrangle. Tomhegan Formation: USGS 

loc. 2750-SD, 2820-SD, Bras·SIIill Lake quadrangle. 

Figured specimen.- USNM 126298. 

Order CAENOGASTROPODA Cox, 1959 

Superfamily LOXONEMATACEA Koken, 1889 

Family LOXONEMATIDAE Koken, 1889 

Genus LOXONEMA Phillips, 1841 

Loxonema cf. L. welleriana Williams and Breger 

Plate 2, figures 14, 16 

Loxonema welleriana Williams and Breger, 1916, p. 279-280, 

pl. 13, figs. 2, 3, 5. 

Description.- A very highspired gastropod with 

shallow sutures. The whorl profile is moderately 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A15 

rounded, and the sutures, while distinct, are not deep. 

The base ois rounded and anomphalous. The columellar lip· is slightly reflexed, but is not thickened. The 

growth lines are unknown, though there is slight evidence of an extremely shallow sinus extending between 

the sutures. Ornament is unknown. 

Remar~.-Several high-spired gastropods of medium size are available; one has the whorl profile well 

preserved. 

Williams and Breger (1916, p. 279-280) identified 

two species of Lowonema from glacial drift boulders 

which had the lithology of the Tarratine Formation 

and contained the brachiopod fauna characteristic of 

that formation. Three specimens were assigned by 

them to Lowonema je,rseyen8e Weller, 1903, and nine 

specimens to a new species, L. welleriana. Several 

specimens in each group retain growth lines, and 

though most of the specimens are not well preserved, 

there is some basis for the distinction drawn by these 

authors. The original of their plate 15, figure 5, is 

here designated the lectotype of L. welleriana; it is 

figured for comparison on plate 2, figure 15. 

Assuming that the two species do exist and that the 

original work did not simply distinguish end members 

of a variable series, the specimens from the Moose 

River district are more similar to L. welleriana. 

Though the presence of a shallow sinus cannot be confirmed, the whorl profile is similar in that the sutures 

are shallow and the whorls are not sharply inflated. 

In contrast, the specimens assigned to L. jerseyen.se, 

although also extremely high spired, have a more incised suture and a more inflated whorl. 

The specimens described by Williams and Breger 

(1916) as Mesoooelia tenuella constitute an enigma. 

No growth lines are evident, nor is a selenizone clearly 

displayed. Perhaps these specimens should also be 

placed within Lowonema welleriana, but tha.tt particular 

problem is beyond the scope of this study. 

Oocurrence.-Seboomook Formation: USGS loc. 2857-SD, 

Brassua Lake quadrangle. Tarratine Formation: USGS loc. 

2701-SD, Brassua Lake quadrangle, 2813-SD, Pierce Lake quadrangle. 

Figured specimens.-USNM 59863, 126309, 126310. 

Phylum ECHINODERMATA 

Class STELLAROIDEA 

Order OPHIUROIDEA 

Unidentified ophiuroid 

Pia te 1, figures 20, 23 

A block of sandstone used as part of a garage foundation in the village of Long Pond, Long Pond quadrangle, Somerset County, Maine, contained the impressions of three ophiuroids, together with those of 

brachiopods characteristic of the Tarratine Formation. 

This block was collected and is figured here because of 

the rarity of fossil ophiuroids. Identification and description· of the specimens is deferred pending their 

examination by a specialist in this group. 

Stratigraphic position.-Tarratin~ Formation. 

Fignred specimen.-USNM 126099. 

Dasycladacean Alga 

Genus MASTOPORA Eichwald 

Mastopora sp. 

Plate 1, figures 16, 17 

Rernarks.-Fragmentary subspherical, calcite-filled 

bodies from the Kennebec Formation, while incomplete, 

are characteristic of fossils usually referred to N idulites. The external surface bears the characteristic_ 

ornament of a honeycomblike surface in which l'.ach 

hexagon is deeply indented by an almost hemispherical 

concavity. Although the material is not of particular 

biological significance, this occurrence is useful for records of geographic distribution of Ordovician fossils. 

Osgood and Fischer ( 1960) have demonstrated that 

the Middle Ordovician fossil cmnmonly cited in the 

literature as Nidulites pyriformis Bassler, and va.riously classed as a sponge, a receptaculitid, or as ineertae 

sedis, seems to be a dasycladacean alga of the genus 

lJf astopora. 

Occurrence.-Kennebec Formation: Loc. USGS-4318-CO, 

Brassua Lake quadrangle, Somerset County, Maine. 

Figured specimens.-USNM 126471, 126472. 

REGISTER OF LOCALITIES 

All collections were obtained from Maine. All the 

numbers are in the permanent register of SilurianDevonianlocality numbers maintained by the U.S. Geological Survey except for 4318-CO which is in the Cambrian -Ordovician register. 
Al6 CONTRIBUTIONS TO PALEONTOLOGY 

USGS Formation Age_ Locality description Collector, locality date USGS Formation Age Locality description Collector, locality date 

27QO-SD __ Moose River Early Edge of central and east- A. J. Boucot, 

Group Devonian. central ninths of Bras- July 14, 

Tarratine sua Lake quadrangle, 1949. 

Forma- Somerset County. 

2813-SD __ Moose River Early De- Northwest ninth of Pierce A. J. Boucot, Group Tar- vonian. Pond quadrangle, 0.11 August 27, ratine mile upstream from the 1949. 

Formation. stream which :flows 

tion. 

2701-SD __ _____ do _______ _____ do ______ ____ .do ____________________ Do. 

through the camp at the north end of En2705--SD __ _____ do _______ _____ do ______ _____ do ____________________ Do. 

2713-SD __ Moose River _____ do ______ Central ninth of Brassua A. J. Boucot, 

Group Lake quadrangle, July6, Tomhegan Somerset County. 1949. 

Formation. 

2718-SD __ Moose River _____ do ______ Southeast ninth of Long A. J. Boucot, 

Group Pond quad- 1948. 

Tarratine rangle. Formatiln. 

chanted Pond, in the 

:first outcrop on the 

north bank of the stream. 2819-SD __ Moose River Devonian ___ West-central ninth of A. J. Boucot, 

Group Brassua Lake quad- 1949. 

Tomhegan rangle, Somerset County. Formation, This outcrop is 0. 7 mile 

Kin eo N. 10° W. of "M" in 2719--SD __ _____ do _______ _ ____ do ______ _ ____ do ___ ----------------- Do. 2720-SD __ _____ do _______ _____ do ______ _____ do ____________________ Do. 

Volcanic Misery Gore. It is on Member. east bank of stream 2721-SD __ _____ do _______ _____ do ______ _____ do ____________________ Do. which crosses Route 15 

2727-SD __ _____ do _______ ____ .do ______ East-central ninth of Long A. J. Boucot, 

Pond quadrangle, about July 4, 

200ft east of Jackman- 1949. 

(Jackman-Rockwood 

road) about 500 feet 

north of road. 

Rockwood road (Route 15), about 3.9 miles east of the Jackman-Long Pond Township bound2820-SD. _ Moose River _____ do _______ Northeast ninth of A. J. Boucot, 

Group Brassua Lake quad- June 20, 

Tomhegan rangle, Somerset County. 1948. 

Formation. On Blaine School2729--SD __ _____ do ________ _____ do _______ ary by odometer. 

East ninth of Spencer H. Woodard, 

Tenmile Swing road, 

about 3.5 miles north of 

quadrangle, on south 1949. 

shore of Spencer Lake, 

the bridge over Moose 

River. This locality is 

2,675 ft northeast from in the ditch on the east the top of the 1,540-ft 

hill. 2731-SD __ _____ do ________ _____ do _______ Central ninth of Long A. J. Boucot, 

Pond quadrangle in JulyS, the railroad cut about 1949. 

side of the road and is 

usually covered by earth 

except when heavy rains have deepened the ditch. 

half a mile from point where the railroad crosses the JackmanLong Pond boundary to the west, and directly north of the 

2750-SD __ Moose River _____ do _______ Route 15 symbol. Northeast ninth of Bras- A. J. Boucot, Group sua Lake quadrangle, 1949. 

Tomhegan Somerset County, Forma- Maine, on end of Baker 

tion. Brook Point. The 

2830-SD __ Moose River Early De- Northwest ninth of A. J. Boucot, 

Group vonian. Moosehead Lake quad- August 1, 

Tarratine rangle. 1949. 

Formation. 2832-SD __ _____ do ________ _ ____ do _______ Southwest ninth of A. J. Boucot, 

Brassua Lake quad- July 9, 

rangle, on the south- 1950. west side of Knob (elevation 2,020 ft) on the 

ridge en echelon to the 

northwest with William 

Mountain. 

actual outcrops are ledges about 100ft in 

from the point. From 

them blocks have been 

moved to the shore, 

where much of the col2852-SD __ Moose River Devonian ___ North-central ninth of J. Bridge 

Group Brassua Lake quad- and P. E. 

Tomhegan rangle, Somerset Cloud, 

Formation. County. 0.6 mile N. Sept. 28, 

47° W. from southeast 1941. corner of most promilection was made. 2766--SD __ Moose River _____ do _______ Central ninth of Long A. J. Boucot, Group Pond quadrangle, a bout July29, Terra tine 700 feet north of the "F" 1949. 

Formation. in Fogg Pond. 2767-SD __ _____ do ________ _____ do _______ Northwest ninth of A. J. Boucot, 

Moosehead Lake quad- July 30, 

rangle. 1949. 2771-SD __ _____ do ________ _____ do _______ ____ .do _____________________ A.J. Boucot, 

August 1, 

2783-SD __ 1949. _____ do ________ _____ do _______ Central ninth of Long A. J. Boucot, quadrangle. North August 10, 

shore of Long Pond, 0.1 1949. 

mile from the point where the 70° 05' West 

nent point near north- west end of Brassua 

Lake. Locality is 320 

feet S. 30° E. from tip of point at high-water mark, and consists of 

several large slabs of 

platy, noncalc., greenish- to bluish-gray, buffgray-weathering finegrained sandstone. 

These slabs are prob- ably very nearly in 

place, but are so slumped that the dip means nothing; they are meridian crosses the 

shore. 2798-SD __ -----do ________ _____ do _______ Northwest ninth of Pierce A. J. Boucot, Pond quadrangle. On August 19, Enchanted Stream, 0.8 1949. 

mile below the outlet of 

2806--SD __ Little Enchanted Pond. 

Moose River _____ do _______ Northwest ninth of Pierce A.J. Boucot, Group Pond quadrangle, in August 22, Tarratine old sluiceway running 1949. Formation southwest from McKenMcKen- ney Ponds, at the foot 

ney Ponds of the ridge formed by Limestone the basement complex. Member. Clastic limestone lies 

alined along the trend 

N. 45° E. which approx- imates the strike. 

2857-SD __ Moose River _ ____ do _______ Southwest ninth of A. J. Boucot, 

Group Brassua Lake quad- August 

Seboomook rangle, Somerset County, 1950. 

Formation. 0.12 mileS. 40° E. from 

the outlet of Chase 

Stream Pond. 

2861-SD __ Moose River _____ do _______ Moosehead Lake quad- A. J. Boucot, 

Group rangle. Scattered out- Sept. 17, 

Tarratine crops on west Moose 1950. 

Formation. Brook Island (island is 

about 50 by 100ft) north of Soccatean 

against the ridge from 

the Ponds to the south- west for about a quarter of a mile, following the 

Point. 

2872-SD __ ----.do ________ _____ do _______ Northwest ninth of Pierce A. J. Boucot, 

Pond quadrangle, in August 

streambed of En- 19,1949. course of the under- chanted Stream 0.15 

ground stream and mile downstream from caves. In scattered 

outcrops and loose slabs 

"S" in "Stream," just above the trail to Little 

which can have come Enchanted Pond. 

only from this horizon. 
PALEOZOIC GASTROPODA, MOOSE RIVER SYNCLINORIUM, MAINE A17 

USGS Formation Age Locality description Collector, 

locality date 

2879-SD __ Moose River Early De- Northeast ninth of Bras- A. J. Boucot, 

Group voniau. sua Lake quadrangle, July 19, 

Seboomook Somerset County. On 1949. 

Formation. shore of Tomhegau 

Cove, on the west side 

of the small point above 

the "T" in "Tomhegan Cove." 

2890-SD __ Moose River _____ do _______ East-central ninth of P. Hurley Group Spencer quadrangle, or and J. 

Tarratine west-central ninth of Thomp- Formation. Pierce Pond quad- sou, 1948. 

rangle. Loose boulder on Hedgehog Mountain, Somerset County. 3090-SD __ _____ do--.------ _____ do _______ Long Pond quadrangle. A. J. Boucot, 

Loose block at Parlin 1953. 

Township, Somerset 

County. 3469-SD __ Hardwood Late Silu- About 0.5 mile west of A. J. Boucot, Mountain rian Hardwood Mountain 1952. 

Formation. (Early and 2 miles north-northLudlow). east of Baker Pond, 

Spencer quadrangle, Somerset County. 3475-SD __ Unnamed L. Llando- Limestone Hill, Stratton C. W. Wolfe, hornfels. vory (pos- quadrangle, Somerset 1952. 

sibly Cr County. C5). 3478-SD __ Tarratine Early De- Baker Pond area, Spencer A. J. BonFormation. von ian. quadrangle, Somerset cot. AuCounty. gust 11, 

1952. 

3479-SD __ Hobbstown Late Silu- Puddingstone Hill about A.J. BonFormation. rian to 1.2 miles northeast of cot, AuEarly De- Baker Pond, Spencer gust 26, 

vonian. quadrangle, Somerset 1952. 

County. 3481-SD __ Seboomook Early De- Baker Pond area, Brassua A. J. BonFormation. von ian. Lake quadrangle, Som- cot, 1952. erset County. 3483-SD __ Hardwood Late Silu- Baker Pond area, Spencer Do. 

Mountain rian. quadrangle, Somerset 

Formation. County. About 2.5 miles 

southwest of Baker 

Pond, 0.4 mile west of 

Spencer Stream. 

3499-SD __ Beck Pond Early De- Center of Spencer quad- Do. 

Limestone. voniau. rangle. About 500ft 

south of outlet of Beck 

Pond. 

360G-SD __ _____ do ________ _____ do _______ Central ninth of Spencer quadrangle, Somerset 

County. 5995-SD __ Unnamed Late Silu- East side of Sally couglom- rian. Mountain, Attean quad- erate. rangle, Somerset County. 4317-CO __ Kennebec Middle East-central ninth of Do. 

Formation. Ordovi- Brassua Lake quad- cian. rangle, Somerset County, about 0.4 mile north- east from railroad over- pass at Somerset Junetion on northwest side 

of abandoned railroad 

(now surfaced for auto- mobile road). 

REFERENCES CITED 

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pl. 34. 

Chadwick, G. H., 1908, Revision of "the New York series": 

Science, new ser., v. 28, p. 346-348. 

Clarke, J. M., 1899a, Fauna Siluriana superior do Rio Trombetas, Estado do Para, Brazil: Rio de Janeiro, Mus. Nac. 

Archivos, v. 10, p.1-48, pls. 1-2. 

---1899b, Molluscos devonianos do Estado do Para, Brazil: 

Rio de Janeiro, Mus. Nac. Archivos, v. 10, p. 49-179, pis. 

3-8. 

---1907, Some new Devonic fossils: New York State Mus. 

Bull. 107, p. 153-291. 

---1908, Early Devonic history of New York and eastern 

North America: New York State Mus. Mem. 9, 366 p., 48 pis. 

Clarke, J. M., 1909, Early Devonic history of New York and 

e·astern North America: New York State Mus. Mem. 9, pt. 

2, 249 p., 34 pis. 

Conrad, T. A., 1838, Report on the palaeontological department 

of the Survey: New York Geol. Survey, Ann. Rept. 2, 

p. 107-119. 

---1842, Observations on the Silurian, Devonian, and Carboniferous systems of the United States with descriptions 

of new organic remains: Phila. Acad. Nat. Sci. Jour., v. 8, 

pt. 2, p. 228-280, pls. 12-17. 

Cox, L. R., 1955, Observations on gastropod descriptive terminology: Malacolog. Soc. London Proc., v. 31, p. 190-202. 

Grabau, A. W., 1913, Preliminary report on -the fauna of the 

Dundee limestone of southern Michigan, in Sherzer, W. H., 

Geological report on Wayne County: Michigan Geol. and 

Bioi. Survey Pub. 12, Geol. Ser. 9, p. 327-378. 

Grabau, A. W., and Shimer, H. W., 1909, North American index 

fossils, v. 1: New York, A. G. Seiler and Co., 853 p. 

Hall, James, 1843, Geology of New York, part IV, comprising 

the Survey of the fourth Geological District : New York 

State Geol. Survey, 683 p., 19 pls. 

---1859, Descriptions and figures of the organic remains of 

the lower Helderberg group and the Oriskany Sandstone, 

1855-1859: New York State Geol. Survey, Palaeontology, 

v. 3, 532 p., 120 pls. [Knight (1941, p. 393) notes that this 

work appeared in1860 and 1861]. 

---1861, Descriptions of new species of fossils from the 

upper Helderberg, Hamilton and Chemung groups, with 

observations upon previously described species: New York 

State Cabinet Nat. History, 14th Ann. Rept. Regents Univ., 

p. 99-109. 

---1862, Contributions to paleontology, comprising descriptions of new species of fossils from the upper Helderberg. 

Hamilton and Chemung groups: New York State Cabinet 

Nat. History, 15th Ann. Rept. Regents Univ., p. 29-198, 

11 pls. 

---1876, Illustrations of Devonian fossils : Gasteropoda, 

Pteropoda, Cephalopoda, Crustacea and corals of the 

upper Helderberg, Hamilton and Chemung groups : New 

York State Geol. Survey, Palaeontology [Issued in 100 

copies, plates reproduced in 1879]. 

---1879, Gasteropoda, Pteropoda and Cephalopoda of the 

upper Helderberg, Hamilton, Portage and Chemung groups: 

New York State Geol. Survey, Palaeontology, v. 5, pt. 2, 

492 p., 113 pls. 

Hall, James, and Whitfield, R. P., 1875, Plates for descriptions 

of new species of fossils from the vicinity of Louisville, 

Kentucky, and the falls of the Ohio: New York State Mus. 

Nat. History, 27th Ann. Rept. Regents, p. 181-200 [text 

published in 24th Ann. Rept. 1872]. 

Horny, Radvan, 1962, New genera of Bohemian lower Paleozoic 

Bellerophontina: Czechoslovakia, "Ostfedni Ustav Geologicky, Vestnik, v. 37, p. 473-476. 

---1963, Lower Paleozoic Bellerophontina ( Gasteropoda) of 

Bohemia : Czechoslovakia, Sbornik Geologickych Ved. Paleontologie, fada P. v. 2, p. 57-164, pls. 1-44. 

Hubbard, G. D., and others, 1915, Description of the Columbus 

[Ohio] quadrangle: U.S. Geol. Survey Atlas, Folio 197. 

Kindle, E. M., 1901, The Devonian fossils and stratigraphy of 

Indiana: Indiana Dept. Geology Nat. Resources, 25th Ann. 

Rept., p. 529-758, 31 pis. 

Knight, J. B., 1941, Paleozoic gastropod genotypes : Geol. Soc. 

America Spec. Paper 32, 510 p., 96 pls. 
A18 CONTRIBUTIONS TO PALEONTOLOGY 

Knight, J. B., 1944, Paleozoic Gastropoda, in Shimer, H. W. and 

Shrock, R. R., Index fossils of North America: New York, 

John Wiley & Co., p. 437-479. 

Knight, J. B., Batten, R. L., and Yochelson, E. L., 1960, [Descriptions of Paleozoic Gastropoda] in Moore, R. C., eel., 

Treatise on invertebrate paleontology, pt. I, Mollusca 1: 

New York and Lawrence, Kan., Geol. Soc. America and 

Kansas Univ. Press, 350 p. 

Meek, F. B., and Worthen, A. H., 1865, Contributions to the 

palaeontology of Illinois and other western States: Phila. 

Acad. Nat. Sci. Proc., 2d ser., v. 9, p. 245-273. 

---1868, Palaeontology: Illinois Geol. Survey, v. 3, p. 291-

572, pls. 1-20. 

Nettleroth, Henry, 1889, Kentucky fossil shells: Kentucky Geol. 

Survey, 245 p., 36 pls. 

Northrop, S. A., 1939, Paleontology and stratigraphy of the 

Silurian rocks of the Port Daniel-Black Cape region, Gaspe: 

Geol. Soc. America S'pec. Pa.per 21, 302 p., 28 pls. 

Oliver, William A., Jr., 1960, Devonian rugose corals from 

northern Maine: U.S. Geol. Survey, Bull. 1111-A, p. 1-23, 

pls. 1-5. 

Osgood, R. H., Jr., and Fischer, A. G., 1960, Structure and 

preservation of Mastopora pyrifonnis, an Ordovician dasycladacean alga: Jour. Paleontology, v. 34, p. 896-902, pls. 

117-118. 

Saul, J. l\L Boucot, A. J., and Finks, R. M. 1963, Fauna of the 

Accraian Series (Devonian of Ghana) including a revision 

of the gastropod Plectonoftts: Jour. Paleontology, v. 37, 

p. 1042-1053, pls. 135-138. 

Stauffer, 0. R., 1911, Historical or areal geology, in Stauffer, 

C. R., Hubbard, G. D., and Bownocker, J. A., Geology of the 

Columbus quadrangle: Ohio Geol. Survey, 4th Ser., Bull. 

14, p.ll-50. 

"Williams, H. S., and Breger, C. L., 1916, Fauna of the Chapman 

sandstone of Maine including descriptions of some related 

species from the Moose River l'mndstone: U.S. Geol. Survey 

Prof. Paper 89, 347 p, 27 pis. 
A Page· 

adju.tor, Bembexia _______________ _______ A4, 8; pl. 2 

Pleurotomaria_ __ _________ _____________ __ 8, 9 

(Lophospira) _ _ _________ _ ____________ 8 

alatus, Euomphaloptems_ ___ 10 

Alga, dasycladaeean__ ____ ______________ 15 

american-us, Tropidodisws _ _ _ _________________ 6 

Tropidodisws minim-us ___________________ _ 

antiqua, Holopea_________ ____________________ 10 

Archaeogastropoda___________________________ 3, 14 

aroostook!, Platyceras (Orthonychia)___________ 11 

astraliformis, Trochus_ _ ________ _____________ 13 

B 

belandi, Crossoceras ___________________ 4, 11, 12; pl. 3 

bellatula, isonema_____________________________ 12 

Loxonerna (Isonema)______________________ 12 

bellattdum, Callonema_ ___________________ 12 

Elasmonema _________________________ 4, 12; pl. 3 

Loxonema _________ -~ __ ___ ________ __ _ __ _ __ 12 

Bellerophon (Patellostium) revolvens___________ 3 

(Plectonot-us) fraturnus __________________ _ 

gas pens is_____________________________ 7, 8 

trilobattts _ _ ___ ___ _ __ _ ___ ___ ___ _____ ___ 7, 8 

plenus_______ _ __ __ _ ____ _ ___ ____ ____ ______ _ 5 

trilobatus ________________________________ _ 

Bellerophontacea_____________________________ 3, 4 

Bellerophontidae_ __ _ _ _ _ ___ ___ _ __________ _ ___ _ 6 

Bellerophontina _____________________________ _ 

Bernbexia_ _ _____ _ ___ _ _ _ _ __ _ ____ ___ _ ___ __ _ ____ _ 8, 9 

adjutor ________________________________ 4, 8; pl. 2 

ellenae__ _ __ _ __ _ ______ _ _______ __ _ ____ ___ _ __ 9 

brevilineatus, Bucanella ___________________ 4, 5; pl. 1 

Tropidocyclus_____ ___ ___ __ ___ __ _ _ ______ _ _ _ 5 

Bucanella_ _ _ ______ _____________ ____________ __ _ 5, 7 

brevilineatus_ _________________________ 4, 5; pl. 1 

nana __________ -------------------------- 5 

Bucanellinae _ _ _ _ _ _ ___ _ __ _ ___ _ __ _ __ __ ____ __ _ _ _ 5 

Bucaniella trilobata viramundo _______________ _ 

c 

Caenogastropoda____________ ________________ 14 

Callonema bellatulum_ ------------------------ 12 

carinatum, Platyceras __ ----------------------- 10 

chapmani, Goniostropha_______________________ 14 

compressa, Platyceras (Orthonychia)___________ 11 

compress-urn, Platyceras_ ______________________ 10,11 

Crenistriella _ _ _ _ ___ ____ _ __ __ ____ _ ____ __ ___ _ __ _ 5 

Crossoceras_ __________________________________ 11, 12 

belandi_ __________________________ 4, 11, 12; pl. 3 

newberryL __ _ _ __ ____ ___ __ _ _ __ _ _ ______ _ __ _ _ 12 

curvilineatus, Tropidodiscus___________________ 6 

D 

Dasyeladacean alga__ _______________ 15 

dentalium, Platyceras (Orthonychia)___________ 11 

derbyi, Plectonotns_ _ ________ _________________ 7 

E 

Echinodermata __________ _ 15 

Elasrnonema________ _ ___ _ ____ __ _ _ __ _ __ ____ _ __ _ 12 

bellatulnrn ___________________________ 4, 12; pl. 3 

Elasmonematidae_ --------------------------- 12 

ellenae, Bembexia_____________________________ 9 

Eotomaria (Pleurorima) lucina________________ 8 

Eotomariides______ _ ___ _ __ _ ______ _ ______ __ ____ 8 

INDEX 

[Italic page numbers indicate descriptions] 

Page 

Euomphalopteridae _ _ _ __ _ _ _ _ ____ _ __ ____ _ __ _ __ A 10 

Enomphaloptems_ ---------------------------- 3, 10 

alatus ___________ ______ -------------------- 10 

gasconensis _____________ 4, 13,14; pl. 1; text fig. 2 

valeria_ _ _ _ _ _ __ _ ___ _ _ _ _ _ __ _ ___ ___ _ _ ____ _ __ _ 10 

sp ____________________________________ 4, 10; pl. 1 

Euomphalus rotund-us_______ _________________ 8 

F 

fratnrnns, Bellerophon (Plectonot-us) ____________ _ 

G 

Gammadiscus_ _ _ __ ___ _ __ _ ___ ____ __ ___ ______ _ __ 6 

somersetL ----------------------------- 4, 6; pl. 1 

gasconensis, Enomphalopterns_________________ 4, 

13, 14; pl. 1; text fig. 2 

gaspensis, Bellerophon (Plectonotns)___________ 7, 8 

Plectonotus ____________________________ 4, 8; pl. 1 

Gastropoda___________________________________ 3 

Goniostropha chapmanL ---------------------- 14 Gosseletinidae_________ ___ ____________________ 9 

Gosseletininae___ __ _ __ ____ __ _______________ ___ 9 

H 

hebes, Platyceras (Orthonychia)________________ 11 

Holopea_ ___ ___ ___ _ ______ _ __ ________ _____ __ ___ 10 

antiqna_ ___ ___ _ _______ __ ____________ _ _____ 10 

sp ____________________________________ 4, 10; pl. 3 

Holopeidae_ _______ __ _ ___ ___ _____________ _____ 10 

Isonerna bellatula______________________________ 12 

(Isonema) bellatnla, Loxonema_________________ 12 

J 

jerseyense, Loxonema__________________________ 15 

L 

Lophospira ___________ ------------------------ 9 

(Lophospira) adjntor, Plenrotomaria __________ _ 

sp., Loxoplocns ________________________ 4, 9; pl. 2 

Lophospiridae _ __ __ _ __ _ ___ ______ __ _ __ _ __ _____ _ 9 

Lophospirinae_ _ __ _ __ _ __ _ ___ _ ____ __ _ __ ________ 9 

Loxonema_ ----------------------------------- 14,15 

bellatnlwm __ ---------------- ______________ 12 

(lsonema) bellatnla________________________ 12 

jerseyense_ __ ___ _ _ __ ___ _ _____ ___ __ ____ ___ _ _ 15 

welleriana _________________________ 4, 14, 15; pl. 2 

Loxonematacea_______________________________ 4,14 

Loxonematidae _______________________ -------- 14 

Loxoplocns_ _ _ __ ________ _ ____ ____ __ ___ _ _____ __ 9 

(Lophospira) sp _______________________ 4, 9; pl. 2 

lncina, Eotomaria (Pleurorima)________________ 8 

Monrlonia __ -------------------------- 4, 8; pl. 2 Plenrotomaria_________________ ___________ 8 

M 

McKenney Ponds Member, Tarratine Forma- tion _____________________________ _ 

macrostoma, Patellostiwn______________________ 5 

Mastopora _ _ ___ _____ _ ____________ _________ _ __ _ 15 

sp ______________________________________ 15; pl. 1 

Page 

Mesocoelia tennella_ --------------------------- A15 

Microdomatacea __________________________ ---- 4, 12 

milleri, Platyceras _________________ ---- _____ -__ 11 

rninimns americanns, Tropidodiscns___________ 6 

Misery Quartzite Member, Tarratine Formation______________________________ 3 

Mourlonia _ _ __ _ _ __ _ ___ _ __ _ _ __ _ _ __ _ __ _ __ _ __ ___ _ 8 

lncina ________________________________ 4, 8; pl. 2 

Mnrchisonia ____________________________ ------ 14 

(Murchisonia) sp _____________________ 4, 14; pl. 2 

(Mnrchisonia) sp., Mttrchisonia ___________ 4, 14; pl. 2 

Murchisoniacea ___________________ ------------ 4, 14 

Murchisoniidae ________________ --------------- 14 

Murchisoniina ______ - ______ - ___ --------------- 14 

N 

nana, Bncanella______________________________ 5 

newberryi, Crossoceras_ _ ---------------------- 12 

Platyceras ___________________ ------------- 12 

Nidulites __ ----------------------------------- 1,15 

pyriformis________________________________ 15 

0 

obex, Tropidodiscns _____________ -------------- Ophiuroid _________________________________ 15; pl. 1 

Ophiuroidea ______ ------------ __ ------ __ ------ 15 

Oriostoma __ -------------------- _________ --- __ 3, 13 

sp ___________________________________ 4, 13; pl. 2 

Oriostomatacea ____________________ ----------- 4, 13 

Oriostomatic operculum _________________ 4,13; pl. 2 

Oriostomatidae ___________________ --- ____ ----- 13 

Orthonychia ________ --------- ____ ---- ____ ------ 10, 11 

(Orthonychia) aroostooki, Platyceras __ --------- 11 

compressa, Platyceras_____________________ 11 

dentalium, Platyceras_____________________ 11 

hebes, Platyceras__________________________ 11 

spirale, Platyceras_________________________ 11 

tortuosa, Platyceras_______________________ 11 

sp., Platyceras _______________________ 4, 11; pl. 3 

p 

Patellostium __ -------------------------------- 3, 5 

macrostorna __ ----------------------------- 5 revolvens ______________________________ 3, 4; pl. 1 

(Patellostium) revolvens, Bellerophon___________ 3 

Planorbis ___________ - _____ --------------------

trilobatus _______ - _____ -- ___ ---------------

Platyceras __________________ ------------------ 10 

carinatum ______ --------------------------- 10 

compressum_ ----------------------------- 10,11 

millerL _____________________________ ------ 11 

newberryi_ ____ _ --------;,.--- ________ ------- 12 

(Orthonychia) aroostooki~------------------ 11 

compressa __ ______ ---------------- ____ 11 

dentalium_______________ __________ ____ 11 

hebes _____ ________________________ -_ _ _ _ 11 

spirale __ __ --------------------------- _ 11 tortuosa ___ _______________________ ----- 11 

sp_ ------------------------------ 4, 11; pl. 3 (Platyceras) sp ______________________ 4, 10; pl. 3 

(Platyostoma) ------------ _________ ________ 12 

ventricosum ____________________ 3, 4, 11; pl. 3 

(Platyceras) sp., Platyceras__------------ 4, 10; pl. 3 

Platyceratacea _______________ ----------------- 4, 10 

Platyceratidae __ ----------------------------- 10 

A19 
A20 

Platyostoma ______ _______________________ _ 

Page 

All 

ventricostb'IIL _ __ _ __ _ ____ _ _ __ _ __ _ ___ _ __ _ __ __ 11 

(Platyostoma), Platyceras_____________________ 12 

ventricoswn, Platyceras_ ___________ 3, 4, 11; pl. 3 

Plectonotinae______ __ __ _ ___ _ _ _ _ _ __ _ _ __ _ __ _ __ _ _ 7 

Plectonotus ___________________________________ 5, 7, 8 

derbyL _ __ _ ___ _ __ __ __ _ _ __ _ _ __ _ __ _ __ _ ___ _ __ 7 

gaspensis _____________________________ 4, 8; pl. 1 

salteri____ _ __ _ _ _ __ __ _ _____ __ _ __ __ _ __ __ __ _ __ 7 

(Plectonotus) fraturnlbS, Bellerophon __________ _ 

gas pens is, Bellerophon~-- _ _ __ _ _ ___ _ __ 7, 8 

trilobatus, Bellerophon_____________________ 7,8 

plena, Pleurotomaria __________________________ 9,10 

Stenoloron_ --------------------------- 4, 9; pl. 1 

plenus, Bellerophon__ ___ _ ___ _ _ _ _ _ _ __ _ ___ _ _ __ _ _ 5 

(Pleurorima) lucina, Eotomaria _______________ _ 

Pletbrotomaria adfutor _ ________________________ 8, 9 

lncina_ ____________ ____ _ ___ _______________ 8 

plena_____________________________________ 9, 10 

rotunda___________________________________ 8 

(Lophospira) adjutor______________________ 8 

Pleurotomariacea___ __ _____ _ _ __ _ __ _ _ __ _ __ _ _ _ _ _ 4, 8 

Pleurotomariina __________________________ _ 

Pole·umita_ -------------------------- __ 3, 4, 13; pl. 2 

sp _____________________________________ 13; pl. 2 

Prosobranchia________________________________ 3 

Pseudophoracea_ ------------------------ _____ 4,13 

Pseudophoridae_ _ __ __ _ __ __ ____ ________ __ __ ___ 13 

INDEX 

Ptomatis ___ _____________ --------------------

Ptychomphalides _____ -----------------------

pyriformis, Nidulites _________________________ _ 

R 

Page 

A5 

8 

15 

revolvens, Bellerophon (Patellostium)___________ 3 

Patellostium ________________________ 3, 4, 5; pl. 1 

rotunda, Plettrotomaria____ ___________________ 8 

rotundtts, Euomphalus _ __ _ _ __ _ _ __ _ __ ____ __ _ _ _ _ 8 

Rnedemannia_ _ _ __ _ _ __ __ _ _ _ _ __ _ ____ __ _ ___ __ __ _ 9 

sp ____________________________________ 4, 9; pl. 2 

Ruedemanniinae __ --------------------------- 9 

s salteri, Plectonotus ___________________________ _ 

Seboomook Formation __ --------------------- 3 

Sinuitidae _________ -- _ ------------------- Sinuitinae_ _______ __ ______ __ _ ___ ______ ____ ____ 3 

somerseti, f'ammadiscus _________________ 4, 6; pl. 

Tropidodiscus ( Temnodiscus) ___________ __ _ 

spirale, Platyceras (Orthonychia)_______________ 11 

Stellaroidea______________________ ___ __________ 15 

Stenoloron_ ----------------- ________ __ _ _______ 9 

plena _________________________________ 4, 9; pl. 1 

T 

Tarratine Formation __ ------------- _________ _ 3 

(Temnodiscus) somerseti, Tropidodiscus _______ _ 

Page 

tenuella, Mesocoelia_________ ______ _____ _______ A15 

Tomhegan Formation________________________ 3 

tortuosa, Platyceras (Orthonychia)_____________ 11 

trilobata viramundo, Bucaniella________________ 7 

trilobatus, Bellerophon _______ ------------- _ ___ 7 

Bellerophon (Plectonotus)_________________ 7, 8 

Planorbis ______________ ---------------____ 7 

Tritonophon _________ --------------------- __ __ 7 

Trochina_________________________________ ____ 10 

Troch·us astraliformis__________________________ 13 

Tropidocyclus brevilineatus __ -------------- ____ 5 

Tropidodiscinae_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 6 

Tropidodiscus___ ______ __________ _____________ _ 6 

americanus ____ ----------- _______________ _ 

curvilineatus_ _____________ ________________ 6 

minim us americanus ______ ------------- __ _ ober _____________________________________ _ 

( Temnodiscus) somersetL _________ _______ _ 

sp_ --------------------------------- 4, 6; pl. 

v 

valeria, Euomphalopterus______________________ 10 

ventricosum, Platyceras (Platyostoma) __ 3, 4, 11; pl. 3 

Platyostoma_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 11 

viramundo, Bucaniella trilobata________________ 7 

w 

welleriana, Loxonema ______________ 4, 14, 15; pl. 2 
PLATES l-3 
PLATE 1 

FIGURES 1-4. Patellostium? revolvens (Williams and Breger) (p. A3). 

1. The lectotype, an external impression (X 1..5). Moose River Group, Detroit, Somerset County, 

Maine. USNM 59843. 

2. Side view of latex replica (X 1). Tarratine Formation. Locality 2705-SD, Brassua Lake quadrangle, Somerset County, Maine. USNM 126285. 

3. Adapertural view of same replica. 

4. External view from which this replica was cast, showing flaring aperture and absence of a slit. 

5, 6. "Bucanella" brevilineatus (Conrad) (p. A5). 

Tomhegan Formation. Locality 2820-SD, Brassua Lake quadrangle, Somerset County, Maine. 

5. Left side of latex replica (X 4). 

6. Adapertural view of same replica showing sinuate periphery (X 4). USNM 126369. 

7, 8. Gammadiscus? somerseti (Williams and Breger) (p. A6). 

Tarratine Formation. Locality 2718-SD, Long Pond quadrangle, Somerset County, Maine. 

7. Adapertural view of latex replica showing periphery. USNM 126282. 

8. Right side view of same replica (X 3). 

9, 10, 12, 14, 15. Plectonotus cf. P. qaspensis (Clarke) (p. A8). 

9, 10. Dorsal and side views of compressed juvenile steinkern (X 4). Tarratine Formation. Locality 

2705-SD, Brassua Lake quadrangle, Somerset County, Maine. USNM 126290. 

12. Juvenile steinkern (X 3). Tarratine Formation. Locality 2718-SD, Long Pond quadrangle, 

Somerset County, Maine. USNM 126370. 

14. Mature steinkern showing general profile (X 2). Chapman Sandstone. Presque Isle Stream, 

Chapman Plantation, Aroostook County, Maine. USNM 59845. 

15. Latex replica of exterior clearly showing position of selenizone (X 6) suggested in figure 12. Tarratine Formation. Locality 2718-SD, Long Pond quadrangle, Somerset County, Maine. USNM 

126370. 

11. Stenoloron cf. S. plena (Hall) (p. A9). 

Tomhegan Formation. Locality 2820-SD, Brassua quadrangle, Somerset County, Maine. 

11. Latex replica of slightly distorted exterior (X 2). USNM 126307. 

13. Tropidodiscus sp. (p. A6). 

Lower conglomerate member of Hobbstown Formation. Locality 3479-SD, Spencer quadrangle, 

Somerset County, Maine. Left side view of latex replica of exterior (X 4). USNM 126297. 

16, 17. Mastopora sp. (p. A15). 

Kennebec Formation. Locality 4318-CO. Brassua Lake quadrangle, Somerset County, Maine. 

16. Latex replica of part of a "Nidulites" (X 3) USNM 126471. 

17. Latex replica of a more complete specimen (X 3). USNM 126472. 

18. Euomphalopterus sp. (p. A10). 

Hornfels of late Llandovery age. Locality 3475-SD, Stratton quadrangle, Maine. 

18. Latex replica of incomplete upper surface, showing the frill (X 1). USNM 126274. 

19, 21, 22. "Euomphalopterus" gasconensis Northrop (p. A13). 

19. Whorl fragment showing the peripheral spines (X 3). Unnamed conglomerate. Locality USGS5995-SD, Attean quadrangle, Somerset County, Maine. USNM 144479. 

21. External mold of basal surface and spines (X 1). 

22. Latex replica showing upper surface of spines (X 1). Lower conglomerate member of Hobbstown 

Formation. Locality 3479-SD, Spencer quadrangle, Somerset County, Maine. USNM 126316. 

20, 23. Unidentified ophiuroid (p. A15). 

Tarratine Formation. Loose block from village of Long Pond, Long Pond quadrangle, Somerset 

County, Maine. 

20. Latex replica (X 3). USNM 126099. 

23. Impression of another specimen (X 3). USNM 126099. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 503- A PLATE 1 

23 

PALEOZOIC GASTROPODA AND MISCELLANEOUS FOSSILS 
PLATE 2 

FIGURES 1-3. M ourlonia cf. M. lucina (Hall) (p. AS). 

Tarratine Formation. Locality 2718- SD, Long Pond quadrangle, Somerset County, Maine. 

1-3. Latex replica of exterior in side, basal and apical views (X 3). USNM 1262S8. 

4, 5. Loxoplocus (Lophospira) sp. (p. A9) . 

Kennebec Formation . Locality 4317-CO, Brassua Lake quadrangle, Somerset County, Maine. 

4. Slightly oblique side view of latex replica (X 2). USNM 126277. 

5. Latex replica df exterior of slightly distorted specimens (X 2). USNM 126281. 

6- 10. Bembexia? cf. B.? adjutor (Hall) (p. AS) . 

Tomhegan Formation. Locality 2S2D-SD, Brassua Lake quadrangle, Somerset County, Maine. 

6, 7. Latex replica of exterior in side and oblique basal views (X 3; X 4). USNM 126371. 

8, 9. Latex replica of exterior in side and in slightly oblique views (X 3). USNM 126280. 

10. Latex replica of exterior (X 4). USNM 126293. 

11, 12. Murchisonia (Murchisonia) sp. (p. Al4). 

Tomhegan Formation. Locality 2S20-SD, Brassua Lake quadrangle, Somerset County, Maine. 

11. Side view of latex replica (X 3). USN M 126299. 

12. Side view of latex replica of juvenile stage, the opposite side of the preceding view (X 3). USNM 

126299. 

13. Murchisonia (Murchisonia?) sp. (p. Al4). 

Tomhegan Formation. Locality 2S20- SD, Brassua Lake quadrangle, Somerset County, Maine. 

13. Side view of latex replica (X 1) . USNM 126298. 

14- 16. Loxonema cf. L. welleriana Williams and Breger (p. Ali) . 

Somerset County, Maine. 

14. Latex replica of exterior (X 1). Tarratine Formation. Locality 2813-SD, Pierce Pond quadrangle. 

USNM 126309. 

15. Latex replica of exterior of lectotype; this is taken from the mold figured by Williams and Breger as 

pl. 13, fig. 5 (X 1). Tarratine Formation. Glacial drift in vicinity of Detroit. USNM 59S63. 

16. La tex replica of exterior (X 2). Seboomook Formation. Locality 2857-SD, Brassua Lake quadrangle. USNM 126310. 

17, 19. Poleumita sp. (p. A13). 

Hardwood Mountain Formation. Locality 3483- SD, Spencer quadrangle, Somerset County, Maine. 

17, 19. Side and apical views of fragment (X 1) . USNM 126279. 

18, 22. Oriostoma sp. (p. A9). 

Hornfels of late Llandovery age. Locality 3475- SD, Stratton quadrangle, Maine. 

18. Latex replica of upper surface of a strongly distorted specimen (X 2) . USNM 126314. 

22. Latex replica of slightly distorted specimen in oblique side view (X 2). USNM 126315. 

20, 21, 24, 25. Ruedemannia? sp. (p. A9) . 

Tarratine Formation, Somerset County, Maine. 

20, 21. Latex replica of exterior in side and oblique top views (X 2) . Locality 2813-SD, Pierce Pond 

quadrangle. USNM 126278. 

24, 25. Latex replica of exterior in oblique top and oblique basal views (X 3). Locality 2705--SD, Brassua 

Lake quadrangle. USNM 126368. 

23. Oriostomatid operculum (p. A13) . 

Hardwood Mountain Formation . 

23. Latex replica of exterior (X 2). 

Locality 3469- SD, Spencer quadrangle, Somerset County, Maine. 

USNM 126312. 
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PALEOZOIC GASTROPODA 
PLATE 3 

FIGURES 1- 5. Elasmonema cf. E. bellatulum (Hall) (p. A12). 

Brassua Lake quadrangle, Somerset County, Maine. 

1. Apertural view of !aLex replica showing the narrow umbilical impression behind the reflexed lip (X 3). 

Kineo Volcanic Member of Tomhegan Formation. Locality 2819-SD. USNM 126313. 

2, 3, 4. Latex replica of exterior in ada pert ural view, oblique view, and side view (X 2; X 3; X 3). 

Tomhegan Formation. Locality 2820-SD. USNM 126303. 

5. Side view of somewhat compressed latex replica (X 2). Tomhegan Formation. Locality 2820-SD. 

USNM 126302. 

6-15. Crossoceras belandi Boucot and Yochclson, n. gen. and sp. (p. A12) . 

6-9. Apical, apertural, ada pert ural, and basal views of holotype (X 2). Glenerie Limestone of Chadwick 

(1908) . New York 9W 1 mile north of Glenerie and 1 mile south of Cockburn, N.Y. USNM 

126283E. 

10- 13. Basal, apical, adapertural, and apertural views of paratype (X 1). Same locality as above. 

USNM 126283C. 

14. Adapertural view of a juvenile paratype (X 3). Same locality as above. USNM 126283A. 

15. Latex replica of paratype in adapertural view exterior (X 3). USNM 126286A. Tarratine Formation. Locality 2767- SD, Moosehead Lake quadrangle, Somerset County, Maine. 

16. Holopea sp. (p. A10) 

Tomhegan Formation. Locality 2820-SD, Brassua Lake quadrangle, Somerset County, Maine. 

16. Side view of latex replica (X 2). USNM 126284. 

17, 19, 20, 25. Platyceras (Platyceras'!) sp. (p. A10) . 

17. Latex replica of exterior (X 2) . Tomhegan Formation. Locality 2820-SD, Brassua Lake quadrangle, Somerset County, Maine. USNM 126305. 

19, 20. Latex replica of exterior, and oblique apical views of steinkern (X 2). Tomhegan Formation. 

Locality 2820-SD, Brassua Lake quadrangle, Somerset County, Maine. USNM 126306. 

25. Side view of compressed and distorted specimen (X 2) . Locality 2750-SD, Tomhegan Formation. 

Brassua Lake quadrangle, Somerset County, Maine. USNM 126296. 

18, 21, 22. Platyceras (Platyostoma) ventricosum (Conrad) (p. All). 

Tarratine Formation, Somerset County, Maine. 

18. Apical view of latex replica (X 1). Locality 2767-SD, Moosehead Lake quadrangle. USNM 

126300. 

21. Latex replica of distorted exterior mold (X 1). Locality 2872-SD, Pierce Pond quadrangle. USNM 

126294. 

22. Apical view of steinkern (X 1). Locality 2701-SD, Brassua Lake quadrangle. USNM 126308. 

23, 24. Platyceras (Orthonychia) sp. (p. All). 

Tarratine Formation. Locality 2813-SD, Pierce Pond quadrangle, Somerset County, Maine. 

23. Latex replica of exterior; the center prong of the sinuous aperture is partially obscured by a flap of 

latex (X 1). USNM 126292. 

24. Side view of steinkern of same specimen (X 1). USNM 126292. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 503- A PLATE 3 

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PALEOZOIC GASTROPODA