EIECQ MUSEUM
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SEP 1 11968

BULLETINS =<
OF

AMERICAN
PALEONTOLOGY

(Founded 1895)

Vol. 54

No. 244

GASTROPODS OF THE MIDDLE DEVONIAN
ANDERDON LIMESTONE

By

Rosert M. LINSLEY

1968

Paleontological Research Institution
Ithaca, New York 14850, U.S.A.

PALEONTOLOGICAL RESEARCH INSTITUTION

1967 - 1968
IPRE SIDE NT ee eee 2s AUS oA Re ee Lee SR eae KENNETH E. CASTER
IVIGE=PRESIDEN DT) onsets ecssie suite re SIE ks NN ne Pei ee ae oa WILLIAM B. HEROY
SECRETARY =(DREASURER inset oesaale ey ee Re a Ean eas nese eae REBECCA S. Harris
IRIE CTIOR (hestcereseecsamt ston esccconcassver sen tecesuesian cess cescenenasee th vac deer yeas KATHERINE V. W. PALMER
GOUNSEL: sccc-scssesbecceesed peceucasstoneesceslsdas soucsudeusassstvassatoepesessuncpaenseectrsdesseeses ARMAND L. ADAMS
IREPRESENTATIVE AACN COUNCIL eeccesses-cesceccscecotecdctonseseccesiccenece neesacbestenvee Davip NICOL

Trustees

KENNETH E. CASTER (1966-1972) KATHERINE V. W. PALMER (Life)
DonaLp W. FIsHER (1967-1973) Wuiutiam B. HEroy (1962-1968)
ReBecca S. Harris (Life) AXEL A. OLsson (Life)
DANIEL B. Sass (1965-1971) Hans G. KuGLer (1963-1969)

W. Storrs CoLe (1964-1970)

BULLETINS OF AMERICAN PALEONTOLOGY

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BULLETINS
OF

AMERICAN PALEONTOLOGY
(Founded 1895)

Vol. 54

No. 244

GASTROPODS OF THE MIDDLE DEVONIAN
ANDERDON LIMESTONE

By

Rospert M. LINSLEY

September 5, 1968

Paleontological Research Institution

Ithaca, New York 14850, U.S.A.

=r . Pad, ;
Printed in the United aa oe ae
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CONTENTS

PAGE

Ds NSCS REGS eB sy ey pb pe a he NEE. EI EA a EP EE 333
SEU Ali EAC CARN ENE osc ae a coca aaa Bs Fd tsa aoa soos poe Fouts asap aero oe 333
Stratisraphyof the Anderdom Wirestowe, 22oo0 ooo cs. nose cn orecc secretes ener eee 335
Perroitekiver Group — Wueas WD OlOmtte! Fcc cece cena e eres eee a oe csc 342
DI UMACE RE IIMECSLONC Boonie. occ eccrine Be see Mee Ein Soa en seco eae 344
Detroit River Group — Anderdon Limestone -22.220200022020022cecccscceccee reece teense 344
Stratigraphic correlation of the Anderdon Limestone — 00. 346
Oceurrence.0b gastropods 25.222. 222 ee ere ee eee ee ee eae S354
ACO CCONO LV vey a et a ee, PN cas seers ated tains eatiuEnd ee ee ne 360
Preservation and preparation Of TAtCK IANS (5 cco cicccccccc escent se 362
SV SEE RIEA GIO LC SCE UPI EL ONS ig ee oc ence ee eae oso func aera acer Boe es 365
Belleropiontidae., > 2-28 irre ees Se DE sD) Stee Saar eNO ore oe 365
ICAI TG EM ces eens A See eager epee a eee eevee seers 372
OOM atId Ae, 8 2 ee ec ee ee Se ee ee Dea pics vee o ce oor oe se SAS
NEOPM OS PLLC AC Se ee hd eee PEST eae SRE Dee eee 383

Fie Ap ES LOMREACI CDC WN eee eee en a ee se ee ee ba eae 384
OSL LOM ELC cd Ca ree eS De a ee gs nh ee 394

(GO SSCRC EMAIL te ee wer on a eased poor ea Tinie 396
VAtVCCHACL AC ee ers ote cote ee ek De oe hao ae te esac Pes) anieer te _ 405
IVECO GLOLIN AGL ch Cow tere erent a AG fe der elie, eh I te IR a sac Sect eo ee 406
Anomphalidae — Bars Vey 8 ROU A en eee ee: reel Ty Petes a eee ee 411
Peeudopioridae soo ee cere BE) res oe NT Sa ae seers 413
INGLIEO PSIG ACen neo ee eee eee: oP: Seer SE A ES Ba ee ENS Se 2 ce 414
WAI CEII SRD pees ete and eo RL Le ee ee eee 420
BAlacozyeOpleunid dem 2 pe eee eh. ee a ae re es 435

S ELE DEACICI Ga Cee ee eae: Ses SREY cette Deploy ee 438

MEIC TAt (Un Cm CAGE Case = meer eee am i a eee Shee ce, Reve ee Pree Se ee 438
ELLA ese ee ena ae ee he ed oe 5 ak Oy oe ee ns ee ee 445

‘TEXT-FIGURES
i Aertal geologic map 22202. SE er aioe oe Be Pena eS Make Be ee ee SOSA 0
2. Drawing from aerial view ..................... oho Eg Re Finn Atos BRN 5. PE ROPER 345
‘TABLES
ine Numeral count of sdentitiablep specimens <2... 2222.2. cre se tee eee 353

2. Relative frequency of occurrence [species] per quarry —. 355

re

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GASTROPODS OF THE MIDDLE DEVONIAN
ANDERDON LIMESTONE

Rosert M. LINSLeY

ABSTRACT

This paper is concerned with the stratigraphic occurrence and study of
the large and interesting gastropod assemblage found in the Middle Devonian
Anderdon Limestone. This limestone is the uppermost unit of the largely
calcareous Detroit River Group and its area of outcrop is apparently limited
to southeastern Michigan, sourhwestern Ontario, and northwestern Ohio. The
overall stratigraphic position of the Anderdon Limestone is briefly discussed,
though because of the limited value of gastropods as index fossils, this fauna
provides little additional information regarding its relative age. The com-
parative ages of the three gastropod beds of the Anderdon are discussed, and
it is here suggested that they are not synchronous.

The paleoecological setting is also discussed briefly. In general it was
found that there are two primary ecologic environments represented within the
Anderdon. One of these environments consists primarily of a biostromal aggre-
gation of corals and the gastropods apparently lived in this protected en-
vironment. The gastropods inhabiting this biostrome are predominantly small
and this environment is represented in all three quarries that were visited
by the author. The second environment is known only from the Brunner, Mond
Canada, Limited quarry of southeastern Ontario and consists of a fine calci-
lutite inhabited by an assemblage of gastropods whose average size greatly
exceeds the average size of those found in the reef environment. This second
environment has been interpreted as being a protected back-reef or inter-reef
environment.

Following the section on paleoecology there is a brief discussion of preser-
vation and techniques. Almost all of the gastropods occur as external molds
in various states of preservaticn. To study the gastropods it was necessary
to make casts of each mold, and this was accomplished by using a_ latex
molding compound. Most photographs used in the plates are of the latex casts.

The bulk of this paper is devoted to systematic descriptions of new genera
and species and to a brief discussion of other mew forms which are not well
enough preserved to warrant description. Over 50 different gastropods have
been discovered in the Anderdon limestone, only two of which have previously
been described.

The gastropods constitute a varied aggregation belonging to 27 genera
representing the superfamilies Bellerophontacea, Macluritacea, Euomphalacea,
Pleurotomariacea, Platyceratacea, Microdomatacea, Anomphalacea, Pseudo-
phoracea, Neritacea, Murchisoniacea, Loxonematacea, and Pyramidellacea.

Of the 50 species discussed, 33 are considered new. Included in these
33 species are six genera which are considered new. They include Ehlersina,
Zalozone, Tylozone, and Nodonema (of the superfamily Pleurotomariacea),
Copidocatomus (of the superfamily Microdomatacea), and Crenulazona (of
the superfamily Murchisoniacea).

GENERAL STATEMENT

This paper deals primarily with a discussion of the gastropod
fauna of the Anderdon Limestone, the youngest formation of the
Middle Devonian Detroit River Group exposed in southeastern
Michigan, northwestern Ohio, and southeastern Ontario. Gastropods
comprise a remarkably large and distinctve element of the fauna
of the Anderdon Limestone. They seem to be restricted to this
limestone and hence are extremely useful in differentiating the An-

BULLETIN 244

WwW
Ww
exe

derdon Limestone from underlying formations of the Detroit River
Group and the overlying Middle Devonian Dundee Limestone.

Over 50 different species of gastropods have been found in
the Anderdon Limestone, but unfortunately many of these are un-
describable at the present time because of a lack of well-preserved
specimens. Nevertheless enough well-preserved specimens were
found to describe 33 new species and six new genera (Ehlersina,
Tylozone, Nodonema, Zalozone, Crenulozona and Copidocatomus).
In all, 50 different species of gastropods belonging to 27 different
genera are discussed.

In addition to the formal descriptions of the species of gastro-
pods of the Anderdon Limestone, a brief account of the stratig-
raphy of the Anderdon Formation is included, as are observa-
tions on the inferred ecology of the Anderdon sea.

This study was initiated at the Museum of Paleontology of
the University of Michigan when the author was a research as-
sistant there. During the last year of work by the author on this
study the research was sponsored by the National Science Founda-
tion, and many of the expenses incurred in the final preparation
of this manuscript were defrayed by grants from the Littauer
Foundation and the Research Council of Colgate University.

Dr. G. M. Ehlers of the University of Michigan suggested this
project as a subject for a doctoral dissertation. Throughout the
entire period of study he proved to be a prime source of inspira-
tion, and the author spent many stimulating hours discussing the
various aspects of this problem with him. Dr, Ehlers also made
available not only the facilities of the University of Michigan Mu-
seum of Paleontology but also provided the basic collection of
Anderdon gastropods that he had collected with the assistance of
Dr. E. C. Stumm and Dr. R. V. Kesling, both of whom are also
associated with the University of Michigan, The author is further
indebted to Dr. Ehlers for his company and guidance on numerous
field trips to the outcrop areas of the Anderdon Limestone.

The writer received many ideas concerning the possible extent
and nature of the Anderdon sea from interesting discussions with
Dr. Stumm. Dr. Kesling also aided the progress of this study with
numerous helpful observations on methodology and techniques. Be-
cause of the small size of many of the gastropods, Dr. Kesling’s

ANDERDON GasTROPODS: LINSLEY 335

familiarity with micropaleontological techniques was particularly
helpful in aiding the writer in preparing and photographing the
specimens. Mr. Herbert Wienert, photographer for the University
of Michigan Museum of Paleontology, helped the author with some
of the photography.

The author greatly enjoyed the friendly and stimulating cor-
respondence with Dr. Ellis L. Yochelson, Dr. Roger L. Batten, and
the late Dr. J. Brooks Knight. All three gentlemen gave unhesi-
tatingly of their time and greatly aided the determination of the
systematic position of many elements of this fauna, as well as
fascinating suggestions regarding many other problems encountered
in the course of this study.

Dr. Henry Van der Schalie of the Museum of Zoology of the
University of Michigan aided the writer with many informative
hours of conversation regarding modern mollusks and thus pro-
vided some possible analogies to the problems encountered in the
Paleozoic snails.

Finally and most gratefully the author acknowledges the many
ungrudging hours his wife, JoAnn Hoehler Linsley, his sister,
Anne E. Linsley, and Mrs. Haskell R. Fenner spent in preparing
this manuscript. They were a never failing source of encourage-
ment and their efforts are sincerely appreciated.

SPRATIGRAPEY OF THE ANDERON LIMESTONE

To fully understand the stratigraphic distribution of the
gastropods described in this paper, it is necessary to briefly de-
scribe the stratigraphy of the Anderdon Limestone.

The term Anderdon Limestone was first used by W. H. Sherzer
and A. W. Grabau (1908, p. 408) for the “middle member” of
the “Upper Monroe” strata, which, according to those authors,
occupy a position between the underlying Sylvania Sandstone and
the overlying Dundee Limestone. No type locality or detailed de-
scription of the Anderdon Limestone was given by those investiga-
tors (op. cit.).

In 1909 Sherzer and Grabau (1909, p. 542) indicated that the
term Anderdon Limestone was taken from the “Anderdon quarry,
in Anderdon township, Essex County, Ontario, about 2 miles east

BuLLeETIN 244

WN
LoS)
ON

of Amherstburg and 15 miles south of Detroit.” They (op. cit.) de-
scribed the lithology of the Anderdon Limestone and the discon-
formity between this limestone and the overlying Dundee Limestone
of the quarry, which is now owned by the Brunner, Mond Canada
ed.

In the same reference, Sherzer and Grabau (1909, pp. 541, 542,
text-figure 1) indicated that the Anderdon Limestone overlies the
Flat Rock Dolomite, which rests on the Sylvania Sandstone, and
is respectively overlain by the Amherstburg and Lucas Dolomites.
They also described (op. cit., pp. 541, 542) the occurrence of the
Anderdon Limestone (not a correlate of type Anderdon Limestone )
of the Detroit salt shaft, presented (op. cit., p. 547) a combined
list of fossils from the “Anderdon bed” of the shaft and from the
type Anderdon Limestone in Anderdon Township, and discussed
(op. cit., pp. 543, 544, 551-553) the correlation and faunal differ-
ences of the Anderdon and other formations of the Upper Monroe.

A. C. Lane, Charles S. Prosser, W. H. Sherzer, and A. W. Gra-
bau (1909, pp. 553-556) presented a classification of the Monroe
Formation of Michigan, Ohio, and western New York. In this
classification the lower part of this “formation” was designated the
“Lower Monroe or Bass Island series,’ composed of four strati-
graphic units, the middle part the “Middle Monroe” having a
single unit, the Sylvania Sandstone, and the upper part the “Upper
Monroe,” containing four units. In ascending order the four divi-
sions of the Detroit River Series were designated the Flat Rock
Dolomite, Anderdon Limestone, Amherstburg Dolomite, and Lucas
Dolomite.

Lane, Prosser, Sherzer, and Grabau (1909, p. 555) stated that

the name Anderdon Limestone was “. . . suggested by the Reverend
Thomas Nattress . . .” and “was adopted by Sherzer and Grabau

for the coral reef limestone exposed in the Anderdon quarry,
Essex county, Ontario, two miles from Amherstburg, Ontario, and
in the salt shaft at Oakwood [part of Greater Detroit], Michigan.”
They (1909, p. 553) also stated that the highest Silurian strata
in America are represented by the Monroe Formation, of which
the Anderdon Limestone is a part.

The Anderdon Limestone was described in considerable detail
and assigned to the Silurian System by W. H. Sherzer and A. W.

ANDERDON GastTROPODS: LINSLEY 61601

Grabau (1910, pp. 42-47). A. W. Grabau (1910, pp. 87-213) de-
scribed several gastropods and other invertebrate fossils from the
“Anderdon limestone”; some species that he stated as occurring
in his Lucas Dolomite of the Detroit salt shaft are now known
to belong to the Anderdon Limestone; others, recorded as found
in the “Anderdon limestone” of the salt shaft, came from strata
that are now known to be of lower Lucas or upper Amherstburg
age. Species, described as having been found in the Anderdon Lime-
stone of the Anderdon quarry, belong to this limestone.

@ ake Stautfer (1916,/pp. 72-77.) im a. paper on’ the relative
age of the Detroit River Series and M. Y. Williams (1919, pp.
18-21) in a publication on the Silurian geology and faunas of
Ontario Peninsula and Manitoulin and adjacent islands reached
the conclusion that the Silurian Series are of Devonian rather than
of upper Silurian age. In making this change in classification,
Williams (1919, p. 22) stated that “terms upper Monroe and
lower Monroe are obviously no longer appropriate, since the so-
called Monroe is now seen to belong to different geological sys-
tems, Grabau’s alternate names ‘Detroit River’ and ‘Bass Island’
[original designation is Bass Islands] will hence be used.”

J. E. Carman (1927, pp. 481-506) concluded that the Sylvania
Sandstone and the overlying Detroit River strata are of Devonian
age, the Silurian-Devonian contact in Ohio being at the base of
the Sylvania Sandstone. Subsequently Carman (1936, pp. 253-266)
described in detail the Sylvania Sandstone of Ohio, noting the un-
conformity at its base and the gradation of the water-laid phase
of the Sylvania into the overlying Detroit River Dolomite.

G. M. Ehlers (1945, pp. 110, 111) regarded the Detroit River
strata as a group and stated (op. cit., p. 118) that the Sylvania

we

Sandstone . on further study may prove to be the lowest for-
mation of the Detroit River Group in southeastern Michigan.” He
(op. cit., pp. 116-120) further showed that the Detroit River strata
occupied a position between the underlying Bois Blanc Formation,
which is a western extension of the Onondaga Limestone (now
designated Bois Blanc Limestone by Canadian geologists) of south-
western Ontario, Canada, and the overlying Dundee Limestone.
In 1950 G. M. Ehlers (1950, pp. 1455, 1456) presented a revised
classification of the Detroit River Group in which the oldest forma-

BULLETIN 244

WN
WNW
(oe)

tion, the Sylvania Sandstone, is successively overlain by the Am-
herstburg Dolomite, the Lucas Dolomite, and the Anderdon Lime-
stone. The Flat Rock Dolomite was regarded by Ehlers (op. cit.)
as a part of the Amherstburg Dolomite and the term Flat Rock
Dolomite omitted in his revised classification.

In 1951, G. M. Ehlers, E. C. Stumm, and R. V. Kesling (pp.
3-17, 23) described the Detroit River Group in considerable detail
and classified (op. cit., Chart 1, p. 10) the Anderdon Limestone
as the youngest formation of this group.

The type section of the Anderdon limestone is exposed in the
Brunner, Mond Canada Ltd. quarry (“Anderdon quarry” of many
auhors) in Anderdon township about 114 miles northeast of Am-
herstburg, Ontario (See map, Text-figure 1).

The rocks of this quarry were described by Ehlers, Stumm,
and Kesling (1951, pp. 11-13) except for emendations by the au-
thor, as follows:

DUNDEE LIMESTONE
Exposed in wall of quarry

Unit Ft. In.
17 ebimestone:, -Wotal sthickness? 2... eS 5

DISCONFORMITY
ANDERDON LIMESTONE

Exposed in wall and floor of quarry

16. Limestone, light gray to light bluish-gray, finely
crystalline, containing Amphipora nattressi (Gra-
bau), an athyrid, a costate Atrypa, Pentamerella sp.,
Leiorhynchus? sp., several genera and_ species of
cephalopods, and many large, loosely coiled, low-
spired gastropods. Molds of gastropods (Euryzone?
sp. A and B) and cephalopods filled or partly filled
with buff, arenaceous and dolomitic-limestone of over-
lying Dundee Formation. Quartz sand of basal Dundee
present in weathered fissures of Anderdon Limestone
to a depth of 4 feet below the top of unit 16 (unit
(xO Stautter, 19.15" 1p. 92,03))ee reas iin A re Pee Ne eee 6

15. Limestone, light buff-gray, crystalline, containing few
stromatoporoids, few poorly preserved tetracorals and
brachiopods, many newly described species of rela-
tively large gastropods, including the genera Zalo-
zone, n. gen., Naticopsis, Crenulazona, n. gen., Ehler-
sina, n. gen., and Tylozone, n. gen. Also present are
the ostracods Barychilina sp., Kloedenia sp. and
species of the ostracod families Cypridae and Leper-
ditidae. (unit 6 of Stauffer, 1915, p. 203).

Ow
w
\O

ANDERDON Gastropops: LINSLEY

14. Limestone, gray, crystalline, with many specimens
of the stromatoporoids, Amphipora nattressi (Gra-
bau), Stictostroma anderdonense Galloway and
Ehlers, Syringostroma aurora Parks, and S. aurorella
Fritz and Waines, many corals including the genera
Cystiphyllodes, Disphyllum, Emmonsia, Favosites, and
Heterophrentis, a costate Atrypa, an athyrid, Cono-
cardium sibleyense LaRocque, undescribed species of
the ostracod genera Aparchites, Isochilina, Kloe-
denia?, and Punctoprimitia. Small low bioherms com-
posed largely of a digitate Favosites in a brown to
brownish-black dolomite having considerable asphaltic
material present locally in quarry. Also present locally
are small biostroms with small gastropods including
Straparollus (Serpulospira) diversiformis Linsley,
n. sp. and Tropidodiscus cultricarinatus Linsley, n. sp.
(Guinitaeseso fe Starter wel OMS espe 2, 03)) er eereees eee eer 4 8
13. Limestone (calcilutite), light buff-gray, banded with
darker gray, with small disseminated crystals of
calcite; lowest 6 inches more buff than rest of unit.
Units 13 to 1 inclusive approximately equivaient to
Unite4 sot, Stautter, (1915 ips 203i) 0 meee eee
12. Dolomite, dark gray to blackish-gray, with scattered
crystals of calcite and grains of quartz sand WW... 5
11. Limestone (calcilutite), very light buff-gray, with
disseminated small crystals of calcite, conchoidal frac-

we
nN

tUmewsan Ges ty-Olite sina. toe ete een eae the ees 2 4
10. Limestone (calcilutite), similar to unit 11, with some
darker gray bands arranged parallel to bedding ............ 3

9. Limestone (calcilutite), light gray to light buff-gray,
Wwaitheconchordallestracture: 2 022 see eae ee 8
8. Limestone, slightly dolomitic, buff to brown, medium
to coarsely crystalline, with discontinuous thin bands
Ofeeray-siinely= crystalline limestone 2. eee 9
7. Limestone (calcilutite), buft-gray to light buff, with
small scattered crystals of calcite and few grains of

quartz sand; lowest 10 inches a calcarenite ................... 3
6. Limestone (calcilutite), light buff-gray banded with

darken wit=o raya Seon sete oe eee ate Be Oey oe 8
5. Limestone (calcilutite), like unit 6 but with wider

pain Smo tefCOl Otani e reren te he Me ee Se 1 2

4. Limestone (calcilutite), lighter buff-gray than unit 5,

without color banding and with conspicuous con-

chroidlall stra Ct ela sees see een ener ene eet oe ey See 1 10
3. Limestone, light gray, with few small vugs of cal-

cite, an earthy feel, and stromatoporoids
2. Limestone (calcarenite), light gray, with small vugs

lined with crystals of calcite;? Amphipora sp. and

AAEELY Tal Cleese tenenn orate te ee Des A ry re eee 1 11
1. Limestone, very light buff-gray, with very few small

crystalssot'calcitesand fey ostracods 2.22 =. as I 8

Total thickness........ 2Ry, 9”

(The biostromal unit here described as Unit 14 is discontinuous
and grades laterally into an inter-reef unit with the same character-
istics as Unit 15.)

340 Bu tietTin 244

DETROIT RIVER GROUP-LUCAS DOLOMITE

Upper 5 to 6 feet exposed locally in quarry floor; re-

mainder in walls of crusher pit.
Units 1-14 of Ehlers, Stumm, and Kesling 2222.2. 29'4"”—29'7"

Total thickness........ 29'4”—29'7”

—F aS
mx —'SSigg, reall x
<7 PPIAN FMS. ) |
Ske ‘My —

\ SH sa
\ ALE ~
Aah se Pe
) eae 4 a ad an
aA eee ‘/ |

SiBLEY gusercees)

» y & / 5 woLL ano ouaRRy
a& oS) / »
2 Clay Center
ps / oS LA 6 Perrysburg y
WHITENOUSE QUARRY 4a /
f
Q]Woterville
wey: Pare RVILLE QUARRY
SOS) :
SS]
SCALE IN MILES

Woodville

Bowling Gree
J

Text-fig. 1—Areal geologic map showing distribution of Devonian rocks, under-

lying Silurian and overlying Mississippian strata in parts of southeastern

Michigan and northwestern Ohio. After Ehlers, Stumm, and Kesling (1951,
Map 1).

ANDERDON GASTROPODS: LINSLEY 341

A second, well-exposed section of the Anderdon Limestone is
exposed in the abandoned quarry of the Solvay Process Company
at Sibley, about 2 miles north of Trenton, Wayne County, Michi-
gan. (See map, Text-Figure 1) The rocks of this quarry, which
is now owned by the Detroit Edison Company, were described by
Ehlers, Stumm, and Kesling (1951, pp. 14-17) as follows:

DUNDEE LIMESTONE

Exposed in walls of quarry

Unit Ft. In.
Units e-Iimoruehlers. Stumm, and “Kesling? 228... 70 5
Total thickness........70 5

DISCONFORMITY
DETROIT RIVER GROUP-ANDERSON LIMESTONE
Exposed in walls of quarry

Unit Ft. In.
8. Limestone, finely crystalline, very light gray, un-
fossiliferous except for few molds of a minute gas-
tropod found near the top of the bed at some places
in quarry; vertical joining and weathered light gray
to white surfaces are conspicuous characteristics of
COANE iat NO eee eee gee
Limestone, finer grained in lower and upper parts;
coarser grained, with some frosted quartz grains in
the middle part; buff. Many carbonaceous laminae in
the upper and lower parts. Unfossiliferous —....... 4
6. Limestone, finely crystalline, dark gray, 2 inches to 8

inches thick, containing small disseminated crystals of

Call citezia UiMEOSSHITRET OU Sim a. eee ene ee a 8
5. Limestone, fine-grained, light gray, unfossiliferous._.... 4
4. Limestone, granular, dark buff to brown at base to

light buff-gray at top. Lowest 3 inches has many

carbonaceous laminae. Above this is a _ band, 3

inches to 4 inches thick, which contains molds of

newly described species including Paleozygopleura

sthleyense Linsley, n. sp., Murchisonia (M.) sibleyensis

Linsley, n. sp., Straparollus (Serpulospira) diversi-

formis Linsley, n. sp., Nodonema granulatum Linsley,

n. sp., and other species of gastropods. Conocardium

sibleyense La Rocque, Diodontopteria chlersi La Rocque

and a few other pelecypods, cephalopods and brachio-

pods are associated with the gastropods. The gastro-

pods and pelecypods are present above and below the

4 inch band but are less abundant. Most of the unit

is characterized by a digitate Favosites and hemis-

pherical and explanate stromatoporoids, in such

abundance as to form a biostrome. A small coarsely

plicate Atrypa is fairly common in the _ biostrome_..... 5 0
3. Limestone, granular, buff, composed of finely com-

minuted shells, locally cross-bedded in lower part.

Contains many quartz grains, especially in the cross-

heddedi= part Untossiliferoug ss eee 5 0

i)
aS

“I

342 BuLLeTIn 244

Unit Ft. In.

2. Limestone, fine-grained, light buff with numerous
carbonaceous laminae. Unfossiliferous -.....................-- 3

1. Limestone, fine-grained, grayish buff separated into
linear and wavy laminae by thin films of carbona-
ceous matter. Upper 3 inches has small areas of dark
gray limestone, some of which simulate pebbles. Many
Stylolites:: Untossiliher Oust jt 2 to cccoeraoeeceese ce ore eee eee cee

bo
n

Total thickness... 23! 9”

DETROIT RIVER GROUP-LUCAS DOLOMITE

Exposed in wall of quarry, sunk in floor of quarry and walls

of crusher pit.

Wnits d=-15 of Ehlers, Stumm! and! Keslings...-. 2-2... 51 3

Total thickness... Bill, Bi

The Anderdon Limestone is exposed in the two France Stone
Company’s quarries, which are located just north of the village
of Silica, Lucas County, Ohio, and about 214 miles southwest of
the business section of Sylvania, Ohio. The larger one of these
quarries was designated the “East Quarry” by Ehlers, Stumm, and
Kesling in figure 1, page 4 of their 1951 publication. The quarry,
indicated in this figure, is bounded on the west by the north-south
trending Centennial Road, on the south by the east-west directed
Sylvania Avenue, and on the north by the east-west bearing Brint
Road (see Text-figure 2). The eastern wall of the quarry is about
% mile east of Centennial Road. The smaller quarry, designated
the “West Quarry” of the France Stone Company in Text-figure
2, is located on the western side of Centennial Road. It extends
northward from Sylvania Avenue for a distance of about 14 mile,
this northward extent being one-half that of the larger quarry.
A recently made pit has been cut through the floor of the quarry
about 1/5 mile north of Sylvania Avenue. Most of the rock taken
from this pit is the Anderdon Limestone; this is hauled by trucks
via a rock cut passageway beneath Centennial Road to a quarry
road near the base of the west wall of the East Quarry, and thence
transported to a crusher located about 1/10 mile south of Sylvania
Avenue. Exposures of the Anderdon Limestone occur in most of

ANDERDON GastTRopops: LINSLEY 343

the west wall of the East Quarry, in the rock cut beneath Centen-
nial Road, and in the walls of the pit of the West Quarry.

The areal distribution of the Anderdon Limestone and other
Middle Devonian rocks of the Silica, Ohio, regions results from
the erosion of the Lucas County monocline. The trend of the
monocline is about N. 10° W.; the average dip of the strata in
this structure is about 6° S. 80° W. As the result of erosion of the
relatively high dipping beds, the various formations appear in nar-
row bands that are closely parallel to the strike of the monocline.
The dip of the strata and the areal distribution of the formations
are indicated by illustrations in the publication by Ehlers, Stumm,
and Kesling (1951, pl. 2, fig. 2 and text-fig. 1).

The section of the Anderdon Limestone described by Ehlers,
Stumm, and Kesling (1951, p. 5) is located in the west wall of
the East Quarry of the France Stone Company and in a short con-
tinuation of this wall, extending southward from Sylvania Avenue
to the rock crusher of this company. The contact between the An-
derdon Limestone and the underlying Lucas Dolomite is well shown
in the part of the wall south of Sylvania Avenue. The lowest unit
of the Anderdon Limestone (unit 1 of Ehlers, Stumm, and Kesling,
1951, p. 5), exposed in wall south of Sylvania Avenue, contains
many gastropods that are described in this paper.

At the time of publication of the paper by Ehlers, Stumm, and
Kesling, the uppermost strata of the Anderdon Limestone were
not exposed. As the result of the excavation of the pit in the West
Quarry and the passageway connecting this pit with the East
Quarry road, a complete section of the Anderdon Limestone be-
came available for examination by the author.

At the time the author made the following description of the
Anderdon section, the south wall of the pit and rock passageway
were in alignment and successively higher beds of the Anderdon
Limestone could be readily examined at pit-floor level as they
dipped sharply to the southwest. During the last two years the
south and north walls of the pit have been shattered by extensive
quarrying; the continuity of the strata can now be recognized
only on few occasions when the much disturbed rock of the walls
and talus material have been removed.

344

BuLLeTINn 244

DUNDEE LIMESTONE

Exposed partly in pit walls and west wall of West Quarry

France Stone Company.

Limestone and dolomitic limestone—after Ehlers, Stumm,

and Kesling (1951, pp. 17,18)

Ft.

In.

5

DETROIT RIVER GROUP-ANDERDON LIMESTONE

Exposed in south wall of pit in West Quarry of France Stone

of

Company and in rock cut passageway beneath Centennial Road,

about one-fifth mile north of Sylvania Avenue

Unit

12.

10.

bo

Dolomite, light buff-gray, mottled with gray; promi-
nent stylolite surface on uneven (?eroded) top of

WING) ee eee peat eee BR RA Le aE at hee Se Sale

Dolomite, buff, medium crystalline, unfossiliferous......

Dolomite, mottled buff and gray, finely crystalline,

LIMOS STINGER OWS, eee ieeee ee ee eee ne

Dolomite, buff with some streaks of gray, unfossili-

PETOMS Sy eos ee tek ee se een eh BER a tele ee ee

Dolomite, gray, mottled with buff, finely crystalline,

UNntOSSIETOUS! 2.4. ea I A ee a eee ee

Dolomite, buff, finely to medium crystalline; lowest
12 inches light buff, mottled with gray; small, ir-

reculan’ Solution (Calitles: scene ee eee ee

Limestone, light gray to buff-gray, thinly bedded,

UnfOSSUIFEeTOUS se. owe ee eee oe ee ee

Limestone, buff-gray, laminated, with laminae con-

tonted® in upper part: unfossiliferous 8... ee

Dolomite, buff-gray to buff, very finely crystalline,
filled wtih vugs and geodes of crystalline calcite; un-

fossiltherous se a tec e e e ee ee

Dolomite, light buff, fine-grained, and laminated;

weathers into layers one to two inches in thickness —_.

Dolomite, dark buff to brown, crystalline, and thick
bedded. Several species of Murchisonia and other
high-spired gastropods occur sporadically in upper
five to ten inches of this unit. Upper one foot of unit

with considerable carbonaceous material .....................-..-

Dolomite, light buff to buff-gray, with vugs_ of
calcite crystals, molds of many small gastropods,
and a smal] number of brachiopods, simple corals, and
stromatoporoids. The most characteristic gastropods
are Muicrodoma_ tricarinata’ (Grabau), Paleozygo-
pleura joanni Linsley, n. sp., Murchisonia (M.) ander-
doniae Linsley, n. sp., Nodonema granulatum Linsley,
n. sp., Straparollus (Serpulospira) diversiformis Lins-
ley, n. sp.. and Tropidodiscus vesculilineatus Linsley,
n. sp. Pelecypods are rarely found associated with
these gastropods. The dolomite has a_pertroliferous
odor when struck with a hammer

Ft.

wn oO

6

+N

np

In.

6

8 to

10 to

2

Total thickness........ 32’5” to 35’4”"

ANDERDON GASTROPODS: LINSLEY 345

According to Ehlers, Stumm, and Kesling (1951, pp. 5, 6)
the Anderdon Limestone in the France Stone Company’s quarries
is underlain respectively by 83 feet and 9 inches to 84 feet and 1
inch of Lucas Dolomite, and 19 feet and 5 inches of Amherstburg
Dolomite. In the east wall of the East Quarry, the Amherstburg
Dolomite is underlain by about 15 feet of Sylvania Sandstone;
in an abandoned quarry just south of Sylvania Avenue and about

wcouse
HL PORTLAMO
cement co

STONE

ano
Glass Samo

Text-fig. 2—Drawing made from an oblique aerial photograph of the Silica,

Ohio, region to show aerial distribution of the Devonian formations and the

main quarries in which they are exposed. Modified from Ehlers, Stumm, and
Kesling (1951, fig. 1, p. 4).

346 BuLLETIN 244

one-fifth of a mile east of Centennial Road, 50 feet of Sylvania
Standstone has been recognized (see Ehlers, Stumm, and Kesling
OS af).

The Anderdon Limestone of the Silica region is overlain re-
spectively by the Middle Devonian Dundee Limestone, Silica For-
mation, and Ten Mile Creek Dolomite. The Dundee Limestone,
which probably rests disconformably on the Anderdon Limestone,
is well exposed in the West Quarry of the France Stone Company
and in the “South” and “North Quarries” of the Medusa Portland
Cement Company. (See Ehlers, Stumm, and Kesling, 1951, figure
1, p. 4 and pp. 17, 18.) The Dundee has a thickness in these
quarries of 61 feet and 5 inches. (See Ehlers, Stumm, and Kesling,
19527, LS.)

The Anderdon rocks exposed in the quarries of the France
Stone Company near Silica, Ohio, and the abandoned Solvay
Process Company’s quarry at Sibley are more closely related to
each other in lithological character than they are to the Anderdon
strata of the Brunner, Mond Canada Ltd. quarry about 14% miles
northeast of Amherstburg, Ontario. Most of the rocks of the two
first mentioned quarries are dolomites and dolomitic limestones;
only a few thin beds in the Anderdon of the France Stone Company
consist of high-calcitum limestone, In the Brunner, Mond Canada
Company Limited quarry most of the Anderdon is a high-calcium
stone.

STRATIGRAPHIC CORRELATION OF THE ANDERDON
LIMESTONE

An examination of the geographic occurrences and_ strati-
graphic relationships of the Anderdon Limestone is essential to an
understanding of the stratigraphic correlation of this formation.
At its type locality, the Brunner, Mond Canada Ltd. quarry in
Anderdon Township, Essex County, Ontario, the Anderdon Lime-
stone is overlain by the Dundee Limestone and underlain by the
Lucas Dolomite. The records of deep wells in the quarry region
show that the Lucas is underlain respectively by two older forma-
tions of the Detroit River Group, the Amherstburg Dolomite and
Sylvania Sandstone. Beneath the Sylvania is a formation that for
many years was known as the Onondaga Limestone but recently

ANDERDON GastTrRopops: LINSLEY 347

designated the Bois Blanc Limestone by Canadian geologists, who
recognized the continuity of the so-called Onondaga Limestone
with the Bois Blane strata of Michigan. In quarries along the
Thames River Valley just east of Ingersoll, Ontario, situated about
115 miles east and 50 miles north of the type Anderdon locality, are
exposures of high-calcium limestones that belong to the Ambherst-
burg and Lucas Formations. In the quarry nearest to Ingersoll, the
Lucas Limestone is disconformably overlain by strata composing
the upper part of the Columbus Limestone, a formation which is
older than the Dundee Limestone (see Ehlers and Stumm, 1951, pp.
1879-1888). The Anderdon Limestone seems to be absent in the
Ingersoll region; if originally present, it has been removed by
erosion prior to the deposition of the Columbus Limestone. Be-
neath the Detroit River rocks of the Ingersoll region is the Bois
Blanc Limestone (formerly “Onondaga limestone”), outcrops of
which occur at nearby places northeast of Ingersoll (see Ehlers
and Stumm, 1951, fig. 1, pp. 1880, 1887). Somewhere between the
Ingersoll region and Buffalo, New York, the Detroit River Group
pinches out (see C. L. Stauffer, 1957, p. 382). Evidence for the
eastward disappearance of the group is well indicated in quarries
near Leroy, New York, located about 40 miles east of Buffalo,
New York. In these quarries, strata of the upper part of the
Columbus Limestone rest on beds of the Onondaga Limestone that
contain the same fauna as the Bois Blanc Formation. From the
preceding information it is obvious that the Anderdon Limestone
and its associated formations composing the Detroit River Group
are not present in New York.

The Amherstburg and Lucas Dolomites are exposed at sev-
eral places in Ottawa, Erie, and Sandusky Counties, Ohio, which
are adjacent or close to the south shore of Lake Erie. The outcrops,
located on the east side of the Findlay arch limb of the Cincinnati
geanticline, have been described by J. E. Carman (1927, p. 500-
502). As in the Ingersoll, Ontario region, the Lucas strata are
overlain by the Columbus Limestone. According to Carman (op.
cit., p. 502), “farther south along the east side of the anticline
(Findlay arch) no outcrops of the Detroit River Formation are
known. The formation is absent in central Ohio, in Delaware and
Franklin counties, and it is probable that the members which exist

348 BuLLETIN 244

in Erie County thin out southward or are overlapped by the
Columbus Limestone in northern Seneca County.” Carman (oP. cit.,
p. 502) also reported the presence of several exposures of the
Lucas Dolomite and one outcrop that is probably Amherstburg
Dolomite around the base of the Bellefontaine outlier, which is
located on the crest of the Cincinnati geanticline in Logan County
about 80 miles southwest of Ottawa County. No occurrence of
the Anderdon Limestone has been reported from this outlier or in
Ottawa, Erie, and Sandusky Counties.

The Anderdon Limestone and its subjacent formations com-
posing the Detroit River Group underlie a narrow belt of land
extending from the Detroit region to quarries near Silica, Lucas
County, Ohio. In the Detroit region the Sylvania Sandstone rests
on the Bois Blanc Formation. Somewhere between this region and
Lucas County, Ohio, the Bois Blane pinches out; in this county
the Sylvania Sandstone rests disconformably on the Upper Silurian
Raisin River Dolomite. South of the Silica region, the Amherstburg
Dolomite is overlapped by the Lucas Dolomite (see Carman, 1936,
pp. 261-263, fig. 5 and Ehlers, Stumm, and Kesling, 1951, p. 23
and fig. 3). According to J. E. Carman (1927, p. 500) “no ex-
posures of the Detroit River formation are known southwest of the
crossing of the Maumee River,’ which is located about 19 miles
southwest of Silica, Ohio. On a map, Carman (1927, Fig. 1, p. 482)
indicated that the Amherstburg-Lucas (map legend) strata con-
tinue southwestward along the strike under a soil cover for a
distance of about 20 miles from the Maumee River. Just how
far the Anderdon Limestone exists south of the Silica, Ohio region,
is unknown.

From the three preceding paragraphs it is obvious that the
Anderdon Limestone is known only from exposures in Anderdon
Township, Ontario, and in outcrops located in a narrow strip of
land, extending from the Detroit region to Silica, Ohio. The lime-
stone apparently does not extend far eastward into Ontario from
Anderdon ‘Township and without doubt is absent in New York
State. Whether small extensions or erosional remnants of the An-
derdon Limestone occur farther south in Ohio and possibly in In-
diana and Illinois can only be determined from information derived
from borings of deep wells.

ANDERDON GastrRopops: LINSLEY 349

The correlation of the Anderdon with other units of similar
age remains an enigma, and the gastropods, because of their en-
demic nature, offer little aid in solving the problem. As a result of
this survey of the gastropods, it would seem that one is probably
dealing with a facies problem, and that the Anderdon is merely
a localized expression of a unit that has different characteristics else-
where. However, because of the limited outcrops available it is
difficult at this point to ascertain the correlatives. The two most
logical contenders for time equivalency are the Lucas Dolomite
and the Columbus Limestone. As one proceeds downdip into the
Michigan basin in the area of Detroit, Michigan, the Anderdon
disappears quickly and the Lucas occupies an apparent analogous
position, thus suggesting that the Anderdon is merely a near-shore
equivalent of the Lucas beds. However, there is no paleontological
evidence to support this conclusion. A more likely possibility is
that the Anderdon is a reefward equivalent of the Columbus Lime-
stone. This is suggested by occurrence in both formations of Wurchi-
sonia (Hormotomina), Isonema, and a few others. This problem
certainly bears much further study before any conclusions can be
reached, although it is essentially in agreement with the conclusions
of Fagerstrom (1962, p. 430).

In a report on the fossil collections from the James Bay low-
land, Dr. Alice E. Wilson (1953, pp. 76-81) presented evidence
indicating the presence of a Bois Blane fauna and apparently De-
troit River and Dundee faunas in the James Bay region. The oc-
currence of the Bois Blanc fauna is definitely shown by Dr. Wilson’s
list of fossils (op. cit., pp. 77-80), which includes the names of
many species of corals, brachiopods, and trilobites characteristic
of the Boic Blane strata of Michigan and southwestern Ontario.
The strata of the James Bay region containing the Bois Blanc
fauna are in the lower part of the Abitibi River Formation. (See
Martison, N. W., 1953, pp. 30-32 and fig. 2 - Correlation chart,
facing p. 18). The middle and possibly some of the upper parts of
the Abitibi River Formation contain strata having specimens of
several Detroit River species. (See Martison, 1953, p. 34, and fig. 2;
Wilson, 1953, p. 76.) According to Wilson (1953, p. 76) and
Martison (1953, pp. 34, 35), beds in the higher portion of the

350 BULLETIN 244

upper part of the Abitibi River Formation have examples of a few
species that are indicative of the Dundee Limestone.

Two species of stromatoporoids that were first described from
the James Bay region are now known to occur in the Anderdon
Limestone. One of these, Syringostroma aurorella, originally de-
scribed by Madeleine A. Fritz and R. H. Waines (1956, pp. 103,
104) from the Upper Abitibi River Formation at Coral Rapids
on the Abitibi River of the James Bay lowland, was recently re-
ported as occurring in the Anderdon Limestone (unit 14 of the
described section) of the Brunner, Mond Canada Ltd. quarry of
southwestern Ontario by Galioway and Ehlers (1960, pp. 93-95).
The other stromatoporoid, Syringostroma aurora, was first de-
scribed by W. A. Parks (1904, pp. 182, 183) from some exposures
on the Kwataboahegan River, which joins the Moose River about
25 miles southwest of the point where this river empties into James
Bay. Examination of map No. 1952-3, which accompanies a report
by N. W. Martison (1953, map in separate map case), indicates
that the strata of the outcrops along Kwataboahegan River are
in the Upper Abitibi River Formation; according to the legend
accompanying this map, the Upper Abitibi River Formation con-
sists of Detroit River and ?Dundee strata. The discovery of
Syringostroma aurora in the Anderdon Limestone of the Brunner,
Mond Canada Ltd. quarry by Galloway and Ehlers (1960, pp.
82, 93) suggests that Park’s specimen of this species probably was
obtained from the strata of the Detroit River part of the Upper
Abitibi River Formation that are correlative with the Anderdon
Limestone.

It seems probable that the collection and identification of more
fossils from the Middle and Upper Abitibi River Formation. will
show the existence of more Detroit River species in this formation.
The occurrence of abundant molds of gastropods in yellowish brown
limestone exposed along the Kwataboahegan River, noted by
W. A. Parks (1904, pp. 180, 186), suggests the occurrence of gastro-
pods in the Anderdon Limestone of southeastern Michigan and
adjacent regions. Professor Parks (op. cit.) did not have time to
make a thorough study of the gastropods along the Kwataboahegan
Kiver. When an intensive study is made, the gastropods may prove
to be Anderdon or Lucas species.

ANDERDON GAstTROPODS: LINSLEY 351

Gastropods, which resemble those of the Anderdon Limestone,
are present in the Stringocephalus zone of the Middle Devonian of
Germany, which occupies a higher stratigraphic position in the
Middle Devonian than the Anderdon Limestone. In this zone are
Straparollus (Serpulospira), Murchisonia (Murchisonia), Euryzone,
Omphalocirrus, Naticopsis, and other genera composing a gastro-
pod assemblage that is much like that of the Anderdon Limestone.

OCCURRENCE OF GASTROPODS

The gastropods from the Anderdon Limestone of the East
Quarry of the France Stone Company were collected from unit
1 of the described section of this formation. This unit, described
in this paper, has a thickness of 14 inches and rests on the Lucas
Dolomite. The gastropods are associated with a proetid trilobite,
orthoconic nautiloids, a few pelecypods, some simple corals and
stromatoporoids, and four or five species of brachiopods.

The gastropods from the Anderdon Limestone of the aban-
doned Solvay Process Company’s quarry at Sibley were collected
from unit 4 of the described section of this limestone. Most of the
specimens were obtained from a band of dolomitic limestone 3 to
4 inches thick located about 3 inches above the base of unit 4,
which is 7 feet and 10 inches above the contact of the Anderdon
with the underlying Lucas Dolomite. The gastropods in this band
are associated with many specimens of Conocardium sibleyense
La Rocque and Diodontopteria ehlersi La Rocque, and few speci-
mens of other pelecypods and cephalopods. Most of the species of
gastropods, pelecypods, and cephalopods of this band seem to be
represented by specimens in lower and higher parts of unit 4.

Unit 4 of the Sibley Quarry is essentially a stromatoporoid-
coral biostrome. It is characterized by numerous large hemispheri-
cal and explanate stromatoporoids, and less numerous specimens of
a digitate Favosites, simple and compound tetracorals, a small
costate Atrypa, and other brachiopods. The stromatoporoids and
corals probably served as protection to the small gastropods, pelecy-
pods, cephalopods, and brachiopods which lived on the bottom areas
between them.

The gastropods of the Anderdon Limestone of the Brunner,

BuLveTin 244

eo
On
bo

Mond Canada Ltd. quarry about 114 miles northeast of Am-
herstburg, Ontario, were obtained from units 14, 15, and 16 of this
formation as it appears in this quarry. Unit 14, like unit 4 of the
Sibley quarry, is a biostrome composed largely of stromatoporoids
and corals. Locally in the Brunner, Mond Canada Ltd. quarry, unit
14 contains small, low bioherms. The gastropods, pelecypods, and
brachiopods of unit 14, like those of unit 4 at Sibley, apparently
lived in a protected environment on bottom areas between the
masses of stromatoporoids and corals. Unit 15 of the same quarry
contains a considerable number of relatively large high and low-
spired gastropods and few small gastropods, stromatoporoids, and
corals. Unit 16 has representatives of the high and low-spired gas-
tropod species of unit 15 and many specimens of a large, discoid,
septate gastropod. The gastropods of units 15 and 16 are not associ-
ated with numerous stromatoporoids and corals as are those of
unit 14. They apparently lived on a sea-bottom on which very fine
calcareous sediments were accumulating. Most of the material
of these sediments may have been derived from the comminution of
the hard part of stromatoporoids, corals, and other invertebrates
and subsequently deposited in water having a depth slightly greater
that that of the habitat of the stromatoporoids, corals and other
invertebrates.

The accompanying Tables indicate the distribution by species
of the Anderdon gastropods in the three quarries. Table No. 1
illustrates a numerical count of all identifiable specimens in the
collection of the Museum of Paleontology at the University of
Michigan. Table 2 represents the percentile composition of the
fauna from each individual quarry. In this chart each species is
expressed as its percentage of the total number of specimens found
in a given quarry. Thus the abundance of a species compared to the
total number of specimens in a quarry can be readily noted. In both
charts the first vertical column to the right of the specific name
represents the species in the France Stone Company quarry. The
second column represents the Sibley quarry, the third vertical col-
umn unit 14 of the Brunner Mond Canada Ltd. quarry, and the
fourth column units 15-16 of the Brunner, Mond Canada Ltd.
quarry. The gastropods of unit 14 and units 15-16 of the Brunner,

353

LINSLEY

ANDERDON GASTROPODS

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ANDERDON GastTRopops: LINSLEY 3517,

Mond Canada Ltd. quarry were tabulated separately because of the
great dissimilarity between the faunas of these units.

Obviously such a table contains many figures which may be
misleading. Species of which only one or two specimens were col-
lected can hardly be regarded as being significant. The author does
not believe that the present ratios of the occurrence of species
found in the Brunner, Mond Canada Ltd. quarry would be main-
tained if as large a collection of specimens were available as is the
case in the other two quarries. Nevertheless, many interesting obser-
vations can be noted from the distribution of specimens available.

Units 15 and 16 of the Brunner, Mond quarry contain an
assemblage of relatively large gastropods preserved in a fine
calcilutite whereas all of the other gastropods are small forms pre-
served in a biostromal aggregation of other fossils. Most of the young
individuals of the larger species are found in the biostromal units
(especially the biotstromal unit at the Brunner Mond Canada Ltd.
quarry); the adults of the larger species are restricted to units 15
and 16 of the Brunner, Mond Canada Ltd. quarry. Eighty-two per
cent of the species found in units 15 and 16 are restricted to these
units; nine per cent of the unrestricted species, consisting of im-
mature specimens, are found in the biostromal units of the Brun-
ner, Mond quarry and the other quarries.

Of the 50 species of gastropods discussed in this paper, 36 per
cent are represented in the France Stone Company quarry, 44 per
cent in the Sibley quarry, 20 per cent in unit 14 of the Brunner,
Mond Canada Ltd. quarry and 44 per cent in units 15-16 of the
Brunner, Mond Canada Ltd. quarry. Of the 18 species found in the
France Stone Company quarry, six are restricted to that quarry. Six
of the 22 species found in the Sibley quarry are found only at that
locality. At the Brunner, Mond Canada Ltd. quarry three out of
15 species are limited to unit 14 and 18 out of 22 species are found
only in units 15-16. This distribution of species is one of the best
examples of the effect of environment on faunal composition. Units
15-16 of the Brunner, Mond Canada Ltd. quarry lie directly on the
biostromal unit 14, yet their gastropod faunas show only the
slightest similarity. The inferred environments of these units will be
treated more fully in this paper under the heading of “Paleoecology.”

Only three species of gastropods have been found in all the

358 BuLLETIN 244

gastropod-bearing beds of the Anderdon beds described in this paper.
Two of these species are the variable and presumably adaptable
Euryzone petilitornata Linsley, n. sp. and Straparollus (Serpulo-
spira) diversiformis Linsley, n. sp. The adults of the third species,
Crenulazona angulata Linsley, n. sp., are restricted to units 15-16
of the Brunner, Mond Canada Ltd. quarry, but only young indi-
viduals have been found in the biostromal units, and one adult
specimen found on a loose block of rock in the Sibley quarry.

Species that have been found in all three biostromal units are
Nodonema granulatum Linsley, n. sp., Murchisonia (Murchisonia)
anderdomiae Linsley, n. sp., and Murchisonia (Murchisoma) stbley-
ensis Linsley, n. sp.

Though there are many species known only from a_ single
quarry, the apparent absence of a species from a particular quarry
may be due to insufficient collecting. Nevertheless there are some
striking examples of restriction. The first is the restriction of the
species of the genus T'ropidodiscus. Three species of this genus have
been named and each species 1s limited in occurrence to one quarry.
Other species which show fairly good evidence of restriction are Bel-
lerophon (B.) stummi Linsley, sp. nov. and Euryzone latitornata
Linsley, n. sp. (See Table 1.) The most striking example is shown
by Grabau’s species Microdoma tricarinata (Grabau) which was
originally described from a specimen found in the Detroit salt
shaft. One hundred and thirty-five specimens of this species were
found in the France Stone Company quarry, comprising almost
one-fifth of all of the gastropods found there. Not a single speci-
men of this species was found in the Sibley or Brunner, Mond
Canada Ltd. quarries, both of which are much closer to the Detroit
salt shaft than the France Stone Company quarry. (See Table 1.)

The gastropod faunas of the biostromal units of the three
quarries are different; the significance of these differences is diffi-
cult to determine. The dissimilarity of the faunas could be due to
temporal evolution or spatial isolation. If spatial isolation, accom-
plished by discontinuous biostromal horizons, is the cause, it would
be expected that geographical proximity would be reflected in
faunal similarity. However, such is not the case. The Brunner,
Mond Canada Ltd. quarry is located about six miles from Sibley,

wal
Ne}

ANDERDON GaAsTROPODS: LINSLEY 3

Michigan, and the France Stone Company quarry is about 40
miles away from the other two. (See map, Text-figure 1.) The faunal
similarities are greatest between the France Stone Company quarry
and Sibley quarry and not so great as between either of these
quarries and Brunner, Mond Canada Limited quarry. France Stone
Company and Sibley quarries have 12 species in common and are
especially characterized by the great abundance of Nodonema
granulatum Lansley, n. sp., Paleozygopleura, and Murchisonia (Mur-
chisonia) stbleyensis Linsley, n. sp. The France Stone Company
quarry and Brunner, Mond Canada Ltd. quarry have only seven
species in common; all of these, except the common Luryzone
petilitornata Linsley, n. sp. and Straparollus (Serpulospira) diverst-
formis Linsley, n. sp., are characterized by being rare in one quarry
and fairly common in the other. Sibley quarry has 11 species in
common wtih the Brunner, Mond Canada Ltd. quarry.

From the above observations it is evident that the faunal
similarities do not closely approximate the geographical relation-
ships of the biostromal units of the three quarries. Sibley quarry
appears to have a fauna that is intermediate in character to those
of the France Stone Company quarry and the Brunner, Mond
Canada Ltd. quarry The gastropod unit at Sibley quarry also has
an intermediate stratigraphic position; it is in the lower middle
part of the quarry section and thus stratigraphically closer to unit
1 of the France Stone Company than it is to unit 14 of Brunner,
Mond Canada Ltd. quarry. Likewise, the gastropod fauna of the
Sibley quarry bears a somewhat closer resemblance to the fauna of
the France Stone Company quarry than it does to that of the
Brunner, Mond Canada Ltd. quarry, even though Sibley quarry
is geographically closer to Brunner, Mond Canada Ltd. than to the
France Stone Company quarry.

From the preceding discussion the author concludes that the
observed faunal differences are more likely due to temporal evo-
lution than to spatial isolation. Further field work, however, should
be done to verify this conclusion. Most of the gastropods in the
collection at the University of Michigan were gathered from loose
blocks blasted from the quarry face. Collecting from the quarry
faces 1s both difficult and hazardous, but if careful collections could

360 Butietix 244

be made layer by layer, it is probable that further significant
differences in faunal assemblages would be found. A collection of
this type has been started, but the results of the study will have

to await publication of a subsequent paper.

PALEOECOLOGY

The sediments of the Anderdon Limestone and their contained
faunas show evidence of two primary ecological settings favorable to
habitation by gastropods; one a “biostromal” habitat, the other an
“inter-reef” habitat. Most of the rock units of the Anderdon lack
fossil remains; a few units contain large local biostromal aggrega-
tions of corals, stromatoporoids, brachiopods, pelecypods, cephalo-
pods, and gastropods. All three quarries visited by the author have a
“biostromal” unit from which gastropod faunas were obtained,
but each of these units is distinctive. Unit 1 of the France Stone
Company contains the most poorly developed “biostrome.” Corals
and stromatoporoids are comparatively rare here and the gastropods
comprise about 5 per cent of the recognizable fauna; brachiopods are
fairly common and pelecypods are almost nonexistent. It is possible
that the corals and stromatoporoids were rendered unrecognizable
by dolomitization. However, the author feels that these two groups
were never as important elements of the ecological setting here as
in the other two quarries. The scarcity of pelecypods and abundance
of brachiopods suggests that the substrate of unit 1 consisted of
coarse material, and thus may be indicative of moderately deep
water. It is problematical just how much transportation this assem-
blage has undergone. It seems probable that some transportation
occurred; the skeletal remains could not have been carried far,
because they are fragile, finely ornamented, and show no effects of
abrasion.

The “biostrome” bed at Sibley (unit 4) differs from that of
the France Stone Company quarry in many respects. It is com-
posed largely of stromatoporoids and favositid corals and thus
represents a true biostrome rather than the more coquina-like
nature of the France Stone Company bed. The coral-stromato-
poroid bed is one of three distinct lithologic facies which make up

ANDERDON GastTRopopDs: LINSLEY 361

unit 4. A second facies consists of many carbonaceous laminae
spaced from an eighth of an inch to one inch apart. The surface
of each lamina is covered with a multitude of badly crushed shells
of an atrypoid brachiopod. Gastropods have never been found on
these carbonaceous laminae though a few have been found in the
limestone between the laminae. The gastropods are found most
abundantly in the third lithologic facies which directly overlies the
carbonaceous laminae. The limestone of this third facies is fine-
grained and light buff gray; it occurs as the matrix for the coral-
stromatoporoid assemblage. It is not known that the gastropods
lived among the stromatoporoids and corals; they probably lived
on the fine muds that were deposited amid the biostrome.

Aside from the lithologic differences noted in Sibley and France
Stone Company quarries, there are also faunal differences; the
differences in the gastropod faunas have already been discussed.
The most striking faunal difference is the abundance of pelecypods
at Sibley quarry. Both Diodontopteria ehlersi La Rocque and Cono-
cardium sibleyense La Rocque are common and attest to the soft,
muddy nature of the sea bottom at this locality. It seems doubtful
that this fauna has undergone any great amount of transportation,
because the preservation of fine ornamentation of the invertebrates
is relatively good and shows little evidence of abrasion.

The ‘“biostromal” unit of the Brunner, Mond Canada Ltd.
quarry (unit 14) is distinct from each of the other two “biostrome”
units of the Anderdon Limestone and the most deserving of the
term “biostrome.” The entire unit, which is almost five feet thick,
is locally a solid mass of stromatoporoids and corals. The snails
are distributed among these corals and stromatoporoids and are
relatively a small per cent of the total fauna. As in the France
Stone Company quarry, pelecypods are scarce. Diodontopteria and
Conocardium are rare in this unit. Apparently the gastropods lived
among the corals and stromatoporoids and particularly on the mud
flats which are found interspersed within the biostrome.

Though it is difficult to evaluate the significance of the small
differences between these biostromal units, basically they all repre-
sent relatively shallow-water deposits wherein the small snails
sought refuge and protection amid the corals and stromatoporoids.

362 BuLLeTIN 244

Most of the snails appear to have lived on the mud flats within the
biostrome where they fed as scavengers or, like the modern pleuro-
tomarians, lived on algae that may also have lived in the intra-
reef mud flats.

In sharp contrast to these biostromal units are units 15 and 16
Brunner, Mond Canada Ltd. quarry which I have tentatively
labeled “inter-reef” units. Locally unit 15 contains large quantities
of tetracorals, particularly Cystiphylloides sp. These coral assem-
blages are localized. Gastropods are rare or absent in these assem-
blages. The limestone surrounding these coral patches is a fine-
grained, high-calcium calcilutite. In addition to the corals, the
fauna is composed primarily of large gastropods (one to five inches
in maximum dimension), a few orthoceraconic and_ breviconic
nautiloids, some articulate brachiopods, and a variety of ostracods.
These invertebrates and their enclosing sediments suggest a shallow
inter-reef habitat where wave action was kept minimal by the
sheltering action of the reefs. It is doubtful that turbulence could
have been appreciable, for the aspidobranch gills of these gastropods
were probably not able to tolerate more than occasional periods of
excessive turbulence.

Unit 16 of the Brunner, Mond Canada Ltd. quarry offers a
variation from unit 15. This thin bed (six inches) has a fauna
comprised almost solely of the large, flat gastropods Euryzone ? sp.
A. and Euryzone ? sp. B and a few representatives of gastropods
characteristic of unit 15. The upper surface of unit 16 is covered with
large mud cracks which have been filled with the basal sandy line of
the Dundee Limestone. Most of the large individuals of Euryzone ?
are found spire downward on this upermost surface. This bed ob-
viously represents near-shore, lime mud flats and the fauna has
without doubt been re-worked by wave action; however, the author
doubts that these species lived far from their burial grounds. The
scarcity of other invertebrates suggests that these species of Eury-
zone ? were well adapted to this near short life.

PRESERVATION AND PREPARATION OF MATERIALS

With a few exceptions the gastropods of the Anderdon Lime-
stone are preserved as natural external molds. Most of these molds,

ANDERDON GASTROPODS: LINSLEY 363

especially those from the Brunner, Mond Canada Ltd. quarry near
Amherstburg, Ontario, were filled to various degrees with calcite
crystals. The calcite crystals were removed with the aid of dental
tools and steel needles mounted in a vibrotool. Large gastropods
from Brunner, Mond Canada Ltd. quarry presented an additional
problem of preparation. Most of these large snails had a steinkern,
which apparently had undergone at least partial lithification prior
to the removal by solution of the shells. In some of these large
snails the steinkern then slumped against one side of the mold and
subsequently became fused to the mold by a later growth of calcite.
The degree of fusion of the steinkern to the mold depended on the
area of contact between the two and also the degree of devlopment
of the secondary calcite crystals. In many specimens the amount
of fusion was so slight that the steinkern readily separated from
the mold with little obliteration of the sculpture shown by the
mold. In other cases the fusion was so great that it is impossible
to separate the steinkern from the mold and thus one-half of many
molds were destroyed.

The amount of crystal growth within the molds varies consider-
ably. In general the specimens from the quarry at Sibley, Michigan,
exhibit the best preservation. The molds here occur in a finely
crystalline limestone; they rarely have any considerable develop-
ment of secondary calcite. The molds in the France Stone Company
quarries are found in a more porous limestone and the molds com-
monly are lined with small calcite crystals. Fortunately these are
easily removable; the crystallization and the removal of the crystals
rarely affects the quality of preservation of the molds.

The amount of secondary calcite is particularly variable in the
Brunner, Mond Canada Ltd. quarry, especially in the inter-reef
unit where the large gastropods abound. Some molds were almost
completely devoid of calcite whereas in other molds the crystals
form such a solid mass as to make a natural cast of crystalline cal-
cite. [he amount of calcite varies spatially within the quarry so that
in some places the molds are clean and at other places they are so
extensively filled that the molds cannot be cleaned.

With few exceptions all of the specimens were collected from
loose blocks found on the quarry floor. This was particularly neces-

364 BuLLETIN 244

sary in the case of the Brunner,Mond Canada Ltd. quarry where
the gastropod zone occurs well above the quarry floor and is almost
inaccessible.

After the molds were carefully prepared they were filled with
Permamold, a latex molding compound. For the smaller specimens
a single coating of latex was sufficient. For the larger specimens
many coats were applied with an appropriate period of drying
between successive coats. The accuracy in preserving detail of the
latex appears to be good, added to which is the fact that it under-
goes only a minimum amount of shrinkage. If greater magnification
than 10x is used the grain of the latex becomes apparent and begins
to detract from the detail of the specimen. No trouble was en-
countered with the size-range of material that is discussed in this
paper. It is the author’s opinion that the latex is of little use for
any gastropods less than five mm. in greatest dimension.

The preparation of the plates was done by the author through
means of facilities extended him by the University of Michigan
Museum of Paleontology. Where it was feasible, standard lighting
was used with the high-light in the upper left-hand corner. Unortho-
dox lighting was deemed necessary to emphasize particular features
of certain specimens. Although the latex used to make the casts is
uniformly white or buff, a coating of ammonium chloride was
applied prior to photographing the specimen for the sake of em-
phasizing fine features of sculpture. For a few, lamp black or black
indelible ink was mixed with the latex so that the application of
the ammonium chloride would provide vivid contrast; this procedure
was found to be unnecessary for most molds. Experiments were
made with various shades of latex. It was found that most indelible
inks would provide most any desirable hue with no apparent ill
effects to the latex. However, there were few molds with sculptural
relief so low that they could not be satisfactorily photographed with
white latex. For the most part the coloring was unnecessary.

The systematic descriptions were patterned after the style set
by Knight (1941, pp. 15, 16) and followed by Yochelson (1956).
The descriptions basically include a general description of the shell,
followed by a detailed description of the apex, whorl shape, base and
umbilicus, aperture, and ornamentation. Owing to imperfect preser-

ANDERDON GASTROPODS: LINSLEY 365

vation of the specimens, most observations concerning the aperture
had to be derived from a description of the growth lines.

All types and figured specimens referred to in this manuscript
have been catalogued and stored at the Museum of Paleontology
of the University of Michigan.

SYSTEMATIC DESCRIPTIONS
Phylum MOLLUSCA Cuvier
Class GASTROPODA Cuvier
Subclass PROSOBRANCHIA Milne Edwards
Order ARCHAEOGASTROPODA Thiele
Suborder BELLEROPHONTINA Ulrich and Scofield

Superfamily BELLEROPHONTACEA MCoy, 1851
Family BELLEROPHONTIDAE M’Coy, 1851
Subfamily TROPIDODISCINAE Knight, 1956
Genus TROPIDODISCUS Meek and Worthen, 1866
Tropidodiscus Meek and Worthen, 1886, p. 160.

Type species. — Bellerophon curvilineatus Conrad, 1842, p. 269,
by original designation of Meek and Worthen.

Tropidodiscus vesculilineatus Linsley, n. sp. Pl. 25, figs. 4a-c
Tropidodiscus sp. Ehlers, Stumm, and Kesling, 1951, pl. 3, fig. 23.

Description. — Shell smal!, composed of two to three whorls,
isostrophic, doubly phaneromphalous with a sharply angular dor-
sum; whorls adpressed; whorl profile subhastate; whorl face sloping
sharply laterad with gentle concavity from a poorly defined, narrow
selenizone at the periphery, to a convexly rounded, dorso-laterally
situated shoulder, thence continuing with moderate convexity to the
umbilical shoulder; whorl face reflexed at umbilical shoulder and
slightly overhanging on the umbilical slope; umbilical sutures
sharply incised and moderately deep; umbilici moderately wide;
ornamentation consisting of irregularly spaced costae at wide inter-
vals; costae more widely spaced dorso-laterally than ventrally;
costae most strongly developed ventrally, not extending past dorso-
lateral shoulder; shell structure unknown. The holotype is about 7
mm in diameter and 2.8 mm in thickness.

Remarks. — This species is known only from the molds of the
external surface of the shell. The imperfect preservation and the lack
of specimens showing the apertural border make it impossible to de-

366 BuLLETIN 244

termine the exact character of the outer and parietal lips, although
something of their configuration may be approximated from a study
of the growth lines.

The species resembles in general form and ornamentation the
type species of Tropidodiscus, T. curvilineatus (Conrad), from the
Middle Devonian Onondaga Limestone of Schoharie, New York.
It differs from the latter in having the diameter of the shell equal
to one-fourth that of 7. curvilineatus (Conrad) and in having the
whorl face between the selenizone and dorso-laterally situated
shulder slightly concave instead of slightly convex as exhibited by
the similar part of the whorl face of the type species. The ornamenta-
tion differs from that of 7. curvilineatus in having the costae and the
interspaces between the costae much broader in comparison to the
size of the shell.

The species is known from 45 specimens collected from the
France Stone Company quarry near Sylvania, Ohio. It is the only
species of T'ropidodiscus obtained from this quarry and appears to be
restricted to the lower beds of the Anderdon Limestone. The species
is somewhat variable, though most, but not all variations, are due
to age. The costae of most young shells are distinct and broad,
whereas those of old shells are fine and often disappear completely
on the final whorl, The ornamentation is always most pronounced
on the umbilical shoulder and gradually disappears as the dorso-
lateral shoulder is reached. In most shells, especially adults, the
dorso-lateral shoulder is pronounced; three specimens lack this
shoulder and have a uniformly rounded whorl face from the um-
bilical shoulder to the selenizone. In Jacking a dorso-lateral shoulder
these specimens resemble 7. cultricarinatus, n. sp. However, I have
tentatively included these three individuals in 7. vesculilineatus,
n. sp. because their shell sculpture resembles that of this species
more strongly than that of 7. cultricarinatus, n. sp.

A unique feature of 7. vesculililineatus, n. sp. is exhibited by
the holotype (see Pl. 25, fig. 4a). The external mold of the holotype
has a layer of calcite lining part of the mold. The inner surface of
this calcite film reveals beautifully developed costae, which are
broad and are separated by equally wide interspaces. The costae of
this surface, like those of the outer surface of the shell, do not extend

ANDERDON GaAstTROPODS: LINSLEY 367

past the dorso-laterally situated shoulder. They are more regular
and more strongly developed than those of the outer shell surface,
whose costae are obscure and irregular and on the adult portion
of the whorl appear to be more like growth lines than true costae.

Various interpretations of the above-mentioned characteristic
of the shell are possible. According to Béggild (1930, p. 299) the
shells of the Bellerophontacea consist of a single layer of aragonite.
If this statement is truly applicable to all bellerophontids then the
shell of 7. vesculilineatus must have had more well-devloped orna-
mentation on the inner surface than it did on the outer surface.

The most probable explanation is that two shell layers of com-
pletely different composition or structure were present. If the inner
shell layer were originally aragonitic and the outer layer calcitic,
it would be feasible that the inner aragonitic layer could be dis-
solved and that the outer calcitic layer resisted solution and was
altered to secondary calcite at a later date, thus preserving its
ornamentation and an impression of the inner layer. Although it
would seem unusual that the inner shell layer should possess more
prominent sculpture than the outer layer, there are some modern
forms which may be cited as possible analogies. Both Donax vittatus
( Bégegild, 1930, p. 287, pl. 6, fig. 6) and Chiton sp. (op. cit., p. 297,
pl. 8, figs. 4, 5) show evidence of a similar occurrence of “costae”
on the lower shell layer, though on a much smaller scale than the
case in question.

A third possible interpretation is that a thin inductura cov-
ered the entire shell. Many bellerophontid gastropods develop in-
ductural deposits in the area of the umbilicus, and it might be pos-
sible that what has been referred to as the “outer shell layer” is an
inductura covering the entire shell, thus masking the well-developed
costae of the “lower layer.” If this interpretation is correct it would
still seem necessary to have the inductura of a different composition
than the shell so that it could remain present in a few molds while
the shell itself was selectively removed.

At present, the second of the above interpretations holds the
greatest appeal for the author. It seems improbable that the inside
of the shell should show a better development of ornamentation
than the outside. It also seems improbable that an animal with such

368 BuLLETIN 244

a sharply angular dorsum as Tropidodiscus 1s apt to possess a
mantle which envelopes the entire shell, especially since this would
completely negate the purpose of an anal slit of any appreciable
depth. It seems more probable that some of the Bellerophontacea
had more than one shell layer and that one of these layers should be
calcitic. Bogeild (1930, p. 299) mentioned one species of Beller-
ophon that questionably possessed a calcitic, albeit single-layered
shell.

The trivial name of this species, vesculilineatus, is derived from
the Latin vesculus, a diminutive form meaning “weak,” and lineatus,
meaning “of a line,” referring to the weakly developed lines of
ornamentation found on the final whorl of adult shells.

Occurrence. — Locality A - 45 specimens.

Types. — Holotype, No. 30667; figured paratypes, Nos. 30670,
40483; unfigured paratypes, Nos. 30668, 30674.

Tropidodiscus compticarinatus Linsley, n. sp. Pl 25 fig25

Description. — Shell small, isostrophic, doubly phaneromphal-
ous, with sharply angulated dorsum, and two to three whorls; whorls
adpressed; whorl profile subhastate; selenizone situated on relatively
high, angulated dorsal keel; whorl face sloping moderately laterad
from the selenizone to a somewhat rounded, dorso-laterally situated
shoulder, thence continuing with gentle convexity to the um-
bilical shoulder; whorl face reflexed at umbilical shoulder with
little or no overhang on the umbilical slope; umbilici moderately
wide; ornamentation consisting of closely spaced, well-defined trans-
verse costae; costae and interspaces between costae equal in width;
costae slightly more widely spaced and finer at dorso-lateral edge
than at the umbilical shoulder; costae persisting all the way to the
dorsal keel where they merge with the keel; parietal and outer
lips unknown, probably with a deep V-shaped sinus and deep slit
at periphery of outer lip. Shell structure unknown, The holotype
measures about 8 mm in diameter and 3 mm in thickness.

Remarks. — This species is known from a single specimen from
the Sibley quarry. The specimen is preserved as a replacement by
calcite of the original shell material.

The species resembles in general form and ornamentation the
type species of Tropidodiscus, T. curvilineatus (Conrad). It differs

ANDERDON GASTROPODS: LINSLEY 369

from 7. curvilineatus (Conrad) in having the diameter of the shell
equal to one-fourth that of the type species and in having a
higher dorsal keel. The ornamentation is more sharply defined
than that of 7. curvilineatus.

It differs from 7. vesculilineatus, n. sp. in lacking a shoulder
near the selenizone, and in having a smaller umbilical overhang,
a higher selenizonal keel and much more distinctly marked costae,
which are finer, more closely spaced, and extend from the um-
bilicus to the dorsal keel, There is no evidence of a second shell
layer in this species; however, the mode of preservation is distinct
from that of all other specimens of Tropidodiscus found in the An-
derdon Limestone.

The trivial name of this species, compticarinatus, is derived
from the Latin comptus meaning “ornamented” or “adorned” and
carinatus meaning “keeled,” referring to the beautiful ornamentation
provided by the carinae.

Occurrence. — Locality B - one specimen.

Types. — Holotype No. 30671.

Tropidodiscus cultricarinatus Linsley, n. sp. Pl 25) fs) 3a.p

Description. — Small, isostrophic, doubly phaneromphalous
gastropods with a sharply angular dorsum and probably with a
deep V-shaped sinus in the outer lip culminating at the dorsum in
a slit that gives rise to a narrow selenizone; whorl profile hastate,
acutely angulated at the dorsum and umbilical shoulder, sharply
rounded and slightly overhanging on the umbilical slope; sutures
sharply incised and moderately deep; umbilici1 moderately wide;
nucleus unknown; parietal and outer lips unknown; outer lip pre-
sumably with a deep V-shaped sinus culminating at the crest of
the dorsal angulation in a slit of unknown depth that gives rise to
a narrow selenizone; judging from the ornamentation, the margins
of the outer lip leave the umbilical sutures with a slight back-
ward obliquity which gradually increases as they proceed to the
angulated dorsum, resulting in a moderately strong forward con-
vexity; selenizone poorly known, narrow; ornamentation consisting
of numerous, sharp, almost foliaceous transverse costae with inter-
spaces between the costae, equal in width to the costae; costae
strong all the way to the dorsal keel where they merge with the

BULLETIN 244

Ww
ST
(=)

keel: shell unknown, but some evidence existing for a shell of two
distinct layers. The holotype measures 7 mm in diameter and
2.2 mm in thickness.

Remarks. — This species is known from ten specimens collect-
ed from the quarry of Brunner, Mond Canada Ltd. It resembles
the type species T'ropidodiscus curvilineatus (Conrad) in general
form and ornamentation and differs in having the diameter of
the shell equal to one-fourth that of the type species and in pos-
sessing much more closely spaced costae which are sharper and more
foliaceous. It can also be distinguished from 7. vesculilineatus, n. sp.
and 7. compticarinatus, n. sp. by its numerous sharp costae. It can
also be distinguished from 7. vesculilineatus by the fact that the
costae extend out to the angular periphery and the lack of a lateral
shoulder. It can be distinguished from 7. compticarinatus by hav-
ing a lower peripheral keel.

Paratype 40487 (Pi. 25, fig. 3b) shows some evidence that
also may have had a shell composed of two distinct layers, though
the ornamentation is equally strong on either surface.

The three species of V'ropidodiscus found in the Anderdon
Limestone seem to be excellent stratigraphic markers as 7. vesculilin-
eatus is known only from the basal beds of the France Stone Com-
pany quarry (Locality A), 7. compticarinatus only from the inter-
mediate beds of the quarry of the Solvay Process Company at
Sibley (Locality B),
beds from the quarry of Brunner, Mond Canada Ltd. (Locality C).
It is impossible to tell at the present time whether these differ-

and 7. cultricarinatus only from the upper

ences are due to spatiai isolation or temporal evolution, but as
the three localities are all within 50 miles of each other it would
seem that spatial isolation would be ineffective. However, the fact
that these species are found only in biostromal environments sug-
gests the possibility that the inter-reef environments were a severe
barrier to migration.

If further study, based on the finding of more material, should
prove these three forms belong to an evolutionary series, it is
probable the series extends from shells with broad, weak costae of
1’. vesculilineatus, to shells with medium costae of 7. compticarin-
atus, and thence to shells with fine foliaceous costae of T. cultri-
carimatus.

ANDERDON GASTROPODS: LINSLEY Sl

The trivial name of this species, cultricarinatus, is derived from
the Latin culter meaning “knife” and carinatus meaning “keeled.”
The name refers to the sharp foliaceous carinae, characteristic of
this species.

Occurrence. — Locality C - 10 specimens.

Types. — Holotype, No. 40485; paratypes Nos. 40486, 40487.

Subfamily BELLEROPHONTINAE M’Coy, 1851

Genus BELLEROPHON Montfort, 1808

Subgenus BELLEROPHON Montfort, 1808
Bellerophon Montfort, 1808, p. 51.

Type species. — Bellerophon vasulites Montfort, 1808, by orig-

inal designation.

Bellerophon (B.) stummi Linsley, n. sp. Pl.225, figs. -2a-e
Description. — Small, subglobular, narrowly doubly planer-

omphalous, planispiral gastropod with broad, moderately involute
whorls and a narrow, moderately deep slit giving rise to a dorsal
selenizone; whorl profile moderately arched dorsally, with slightly
stronger arching on the sides and turning sharply into the narrow
umbilici; aperture narrowly crescentic; inductura absent; outer
portion of lip unknown, but lip flaring outward in umbilical region;
outer lip apparently with shallow notch culminating dorsally in a
moderately deep (?) sinus; selenizone slightly raised above the
surface of the shell; ornamentation consisting of fine, closely spaced,
transverse costae; shell apparently of moderate thickness, its struc-
ture unknown. Holotype measures 3.75 mm in diameter and 4.50
mm in width.

Remarks. — This species is known from five specimens collect-
ed from the France Stone Company quarry near Sylvania, Ohio.
It resembles Bellerophon (B.) vasulites Montfort, 1808, in general
form and ornamentation but differs from this type species in being
less than one-fifth as large, in having a more narrowly crescentic
aperture, in lacking an inductura, and in having finer ornamenta-
tion.

Occurrence. — Locality A - five specimens.

Types. — Holotype, No. 40512; figured paratype, No. 40511;
unfigured paratypes, Nos. 40510 and 40456.

a2 BuLLeTIN 244

Suborder MACLURITINA Cox and Knight

Superfamily EUOMPHALACEA de Koninck, 1881
Family EUOMPHALIDAE de Koninck, 1881

Genus OMPHALOCIRRUS Ryckholt, 1860
Om phalocirrus Ryckholt, 1860, p. 187.

Type species. —Euomphalus goldfussi d’Archiac and Verneuil,
1842, by subsequent designation, Cossmann, 1915, p. 213.

Ompalocirrus sp. Pl. 39, figs. la, b

Remarks. — One specimen of an apparently undescribed species
of Omphalocirrus was found in the Sibley quarry. Unfortunately
only the mold of the base remains, but that is well preserved. It
resembles the type species Omphalocirrus goldfusst (d’Archiac and
Verneuil) in general form and ornamentation, including the spines
of the “base” (assuming this genus to be dextral). It differs from
the holotype of O. goldfussi in being less than one-third as wide,
in having a more flattened base, and in being apparently less rotund.
The spines appear to be set relatively farther out from the um-
bilicus than are those of the type species. The growth lines are con-
spicuous and unusually placed in bundles of four prominent ones,
set off from the next bundle of four by a space of smooth shell
which bears no apparent growth lines of any sort. Each growth
line of a bundle is parallel to the other growth lines of the same
bundle, but each bundle diverges from its neighbor as it proceeds
from the umbilicus, The last formed growth line of each bundle
swings obliquely backwards near the edge of the shell, truncating
the other growth lines of the bundle to form a large troughlike
spine. This pattern is maintained throughout most of the visible
whorl but is lost on the latest formed part of the shell, possibly
because of the failure to develop a spine at this point.

This undescribed species differs from Omphalocirrus manito-
bensits Whiteaves, 1802, in having a flat (?) base instead of a de-
pressed base as found in O. manitobensis. The latter is also more
than five or six times as wide as the form from the Anderdon
Limestone and lacks the “bundling” of growth lines found in this
form.

Occurrence. — Locality B - one specimen,

Figured specimen. — No. 40385.

Or
—N
>)

ANDERDON GastTROPODS: LINSLEY

Genus STRAPAROLLUS Montfort, 1810
Straparollus Montfort, 1810, p. 174.
Type species. —Straparollus dionysti Montfort, 1810, p. 174,
by original designation.
Subgenus SERPULOSPIRA Cossmann, 1915
Serpulospira Cossmann, 1915, p. 144.
Type species. —Serpulospira centrifuga (F. A. Roemer), 1843,
p. 31, by objective synonymy.
Serpularia F. A. Roemer, 1843, p. 31,
a homonym of Serpularia Minster, 1840.
Type species. — Serpularia centrifuga (F. A. Roemer, 1843), by

monotypy.

Objective synonym.

Straparollus (Serpulospira) diversiformis Linsley, n. sp. Pl. 35,
figs. 3a-e, 4a-d, 5a-e, 6a-d

Description. — Small discoidal gastropods, with later whorls
out of contact with the earlier whorls; whorls slender, subcircular
to suboval in cross-section; sutures deep; nucleus seemingly normal
but not well known, base widely phaneromphalus, shallow to mod-
erately deep; apertural margins free on mature specimens with no
notch, slit or sinus of any kind; ornamentation consisting of growth
lines only; shell seemingly moderately thick to thin, its structure
unknown; the holotype measures 8.3 mm across the upper whorls,
the diameter of the free, final whorl about 2 mm; pleural angle 180
degrees.

Remarks. — This species differs from the type species Serpulo-
spira centrifuga (F. A. Roemer) in being only one-fourth as large
and discoidal at least in the early whorls, and in lacking any indica-
tion of a sinus in the outer lip. The species is common in all three
localities visited by the author and exhibits a considerable amount
of variation which for convenience of reference I have artificially
divided into four types described below as morphotypes. Straparollus
(Serpulospira) diversiformis morphotype “A” is characterized by
being discoidal even in the mature whorls and having the whorls
markedly out of contact after the second volution. S. (S.) diverst-
formis morphotype “B” is characterized by being discoidal with a
slight depression of the adult whorl and by the possession of whorls

374 BuLLeTIN 244

only slightly out of contact after the second volution. S. (S.)
diversiformis morphotype “C” is characterized by being discoidal
for two whorls (as in the other morphotypes) but with succeeding
whorls becoming progressively more and more out of contact with
the preceding whorls and the shell becoming increasingly helically
spired, each successive whorl depressed farther out of the plane of
the earlier whorls. The fourth type, S. (S.) diversiformis morpho-
type “D,” is characterized by having the whorls becoming dis-
engaged and greatly depressed, and deflected outwards at an early
growth stage so that the planispiral stage found in the other three
morphotypes is greatly restricted, the shell becoming helicoid. The
whorls of this variation are greatly disengaged and give the ap-
pearance of being more slender than in the preceding morphotypes.
This series of steps from being only slightly uncoiled in morphotype
“A” to markedly uncoiled in morphotype “D” lends good support
to the proposal by Knight and Bridges (1944) that Serpulospira
Cossmann, 1915, is truly a subgenus of Straparollus Montfort, 1810.
The young specimens would all be considered as Serpulospira mor-
photype “B,” with its limited amount of uncoiling, and this form
is close to that of Straparollus.

The various morphotypes found in the Anderdon Limestone ap-
parently form a continuous series and the boundaries between the
morphotypes are artificial. Any gaps in the pattern would prob-
ably be filled in by future collecting. These various morpho-
types approximate the form of almost ail described species of
Serpulospira and are especially similar to a series described by
De Koninck, as Euomphalus serpula de Koninck, 1883. The diag-
nostic features of S. (S.) diversiformis, n. sp. are the small size and
the completely straight aperture, with no re-entrants.

The trivial name of this species, diversiformis, is from the
Latin diversus meaning “different” and forma meaning “shape or
figure” and refers to the many variations in the form of this species.

Occurrence. — Locality A - 36 specimens; Locality B - 30 speci-
mens; Locality C - 10 specimens.

Types. — Holotype, No. 30680; figured paratypes, Nos. 30681,
30682, 30684, 40445, 40446, 40448, 40449, 40452, 40453, 40454; un-
figured paratypes, Nos. 30683, 30685, 40447, 40450, 40451, 40455.

ANDERDON GastTROPODS: LINSLEY ByFhD)

Straparollus (Serpulospira) diversiformis morphotype “A” Piso:
figs. 3a-e
Remarks. — This morphotype is characterized by its slightly
elliptical whorl cross-section, by distinct uncoiling after the second
whorl, and that all of the whorls lie in one plane.
Occurrence. — Locality A - four specimens; Locality B - five
specimens; Locality C - one specimen.

Types. — Paratypes, Nos. 30682, 40445, 40446.

Straparollus (Serpulospira) diversiformis morphotype “B” P35:
figs. 4a-d
Remarks. — This morphotype is characterized by being coiled

almost completely in one plane, in having the whorls only slightly
disengaged, and in having a subcircular whorl profile.
Occurrence. — Locality A—19 specimens; Locality B—10
specimens; Locality C — five specimens.
Types. — Holotype, No. 30680; figured paratypes, Nos, 40448,
40449; unfigured paratypes, Nos. 40447, 40450, 40451.

Straparollus (Serpulospira) diversiformis morphotype “C” PIR CSD:
figs. 5a-e
Remarks. — This morphotype is characterized by having the

first two whorls coiled in the same plane, then having the subse-
quent whorls disengaged with considerable downward depresssion
and little or no outward deflection. The whorl cross-section is sub-
elliptical, and the whorls appear bulky (as compared to morpho-
type “D”) because of the limited amount of deflection.

Occurrence. — Locality A—12 specimens; Locality B— eight
specimens; Locality C — two specimens.

Types. — Figured paratypes, Nos. 30684, 40452; unfigured

paratypes, Nos. 30683, 30685.
Straparollus (Serpulospira) diversiformis morphotype “D” RIRS3o:
figs. 6a-d
Remarks.— This morphotype is characterized by the marked

uncoiling which begins earlier than the uncoiling in the other three
morphotypes. The early discoidal portion is sufficiently restricted
to give the impression of a helically spired shell. Because of the
rapidity of uncoiling, the whorls give the impression of being more
slender than the preceding morphotypes. Morphotype “D” can be

376 BuLLETIN 244

differentiated from morphotype “C” in that the mature whorls of
morphotype “D” are greatly depressed and greatly deflected from
the earliest whorls, whereas the whorls of morphotype “C” are
strongly depressed downwards but not noticeably deflected out-
wards.

Occurrence. — Locality A— one specimen; Locality B— seven
specimens: Locality C — two specimens.

Types. — Figured paratypes, Nos. 30681, 40453, 40454; un-
figured paratypes, No, 40455.

Subgenus Evomphalus J. Sowerby, 1814
Euomphalus J. Sowerby, 1814 (p. 97).

Type species. — Euomphalus pentangulatus J. Sowerby, 1814,
p. 97, by subsequent designation, Meek and Worthen, 1866 A, p
158.
Straparollus ? (Evomphalus) sp. A Plt 36, fig2

Remarks. — A single specimen was obtained from the Brunner,
Mond Canada Company Limited quarry that apparently belongs to
the subgenus Euomphalus. Only the steinkern and mold of the
upper half of the shell remains; the character of the spire has been
obliterated by fusion of the steinkern with the mold, The speci-
men is a discoidal shell with a depressed spire and a angular
shoulder. The upper whorl face proceeds upward and outward from
the upper suture and rounds off gently to a flat, subhorizontal area
which occupies most of the upper whorl face. The upper and outer
whorl face meet at a sharp shoulder and the two faces are close to
perpendicular to each other. The outer whorl face is only poorly
known, but at least the upper half is flat and subvertical. The
aperture, spire, growth lines and base are unknown. The diagnostic
features of this gastropod are the depressed spire, the flat whor!
faces, and the sharp shoulder.

The specimen measures 51 mm in greatest width.

Occurrence. — Locality D—one specimen.

Figured specimen. — No. 40414.
Straparollus ? (Evomphalus) sp. B Pl s6fig3

Remarks. — One poorly preserved specimen was obtained from
the Brunner, Mond Canada Ltd. quarry that I have hesitatingly

ANDERDON GastTROPODS: LINSLEY Size

assigned to the subgenus Euomphalus J. Sowerby, 1814 (p. 97). It
appears that all that remains of the specimen is an external (? )
mold that is lined with a thick coating of crystalline calcite which
obscures all ornamentation and obliterates any protuberances that
may or may not have been present originally. This gastropod had a
moderately large, discoidal shell with a depressed spire. The upper
whorl face is slightly arched, leading to a strongly rounded shoulder.
The outer whorl face is rounded. The base of the specimen is un-
known. The sutures are broad and deeply incised and located
about the middle of the previous outer whorl face. Aperture and
lip are unknown. Most of the growth lines are obscured by a coating
of crystalline calcite; a few coarse growth lines are visible through
the layer of calcite. On the upper whorl face they are gently oblique
backwards with a slight forward convexity. On the shoulder there 1s
a broad shallow sinus which generates a rounded notch-keel on the
shoulder but does not produce a selenizone. Below the notch-keel
the growth lines continue straight down with a slight forward con-
vexity which ultimately causes the growth lines to have a gentle
backward obliquity. The specimen measures 44 mm in greatest
width. It is possible that this specimen belongs to the same species
as No. 40414, Straparollus ? (Euomphalus) sp. A with the outer
shell layer broken away.
Occurrence. — Locality D—one_ specimen.

Figured specimen. — No. 40415.
Straparollus ? (Evomphalus) sp. C PiSs6ahiess lab

Remarks. — An interesting but poorly preserved specimen was
found in the Brunner, Mond Canada Ltd. quarry. I have hesitat-
ingly assigned this specimen to the subgenus Exomphalus J. Sower-
by, 1814 (p. 97). Whether it belongs to this subgenus or to some
entirely different genus, its structure strongly indicates that the
specimen belongs to the family Euomphalidae de Koninck, 1881.
The mold of the specimen has two distinct surfaces. The outer
surface of the mold presumably represents the outer surface of the
shell while the inner surface of the mold may represent the inner
shell or less possibly the boundary between the inner and outer
shell layers. At one place there is a void separating these two
surfaces as though the thick shell of the gastropod had partially

378 BuLLETIN 244

dissolved at that point, If these two surfaces do represent the
original boundaries of the shell, then this gastropod had a remark-
ably thick shell, as much as 10 millimeters thick at the shoulder.
The shell of this gastropod was moderately large and discoidal,
and had a depressed spire, and a widely phaneromphalous base.
The upper whorl face of the youthful whorls is gently arched and
approximately parallel to the plane of coiling. In the ultimate whorl
the upper whorl face is flat and slopes downward from the shoulder
to the suture, so that the shoulder is noticeably higher than the
spire. The upper whorl face joins the outer whorl face subangularly
to form a prominent roundly angular shoulder. The outer whorl
face is slightly rounded and in general perpendicular to the plane of
coiling. The base is widely phaneromphalous. The basal whorl face
is gently rounded and meets the outer whorl face at a roundly
angular juncture. The sutures are broadly and deeply incised.
Aperture and lip are unknown. The growth lines on the upper and
outer whorl faces are completely obscured as the result of poor
preservation. Vhe growth lines of the base are well preserved and
slope obliquely forward from the umbilical suture with a gentle
forward concavity. The specimen measures 43 mm in greatest width.
Occurrence. — Locality D — one specimen.

Figured specimen. — No. 40416.
Suborder PLEUROTOMARIINA Cox and Knight

Superfamily PLEUROTOMARIACEA Swainson, 1840
Family EOTOMARIIDAE Wenz, 1938
Subfamily EOTOMARIINAE Wenz, 1938
Tribe PTYCHOMPHALIDES Wenz, 1938
Genus MOURLONIA de Koninck, 1883

Mourlonia de Koninck, 1883, p. 75.

Type spectes.— Helix carinatus J. Sowerby, 1812, p. 34 by
original designation.

Mourlonia ? sp. Piesike tices

Remarks. — One specimen, consisting of two whorls, was found
in the France Stone Company quarry and is regarded as belonging
to the genus Mourlonia in its broadest interpretation. The specimen
is a small, subtrochiform gastropod presumably with a shallow sinus
in the outer lip culminating in a slit of unknown depth that gives

ANDERDON GastrRopops: LINSLEY 379

rise to a selenizone at the periphery. The upper whorl face is gently
arched between the upper suture and the periphery. The selenizone
is situated on a low keel at the peripheral angulation which is
formed by the junction of the upper whorl face and the base. Im-
mediately beneath the selenizone is a narrow concave area about
equal in width to the selenizone. The base slopes inward sharply
from the selenizone. The sutures are sharp, and are about a
selenizone’s width beneath the selenizone of the preceding whorl.
The base is poorly known but gently arched just below the seleni-
zone. [he aperture 1s completely unknown, but judging from the
growth lines the outer lip proceeds from the upper suture to the
selenizone with moderate backward obliquity and slight forward
convexity. Below the selenizone the growth lines show the outer
lip to have had only a slight backward obliquity and slight forward
concavity. The selenizone is slightly raised above the level of the
neighboring surface of the shell and is bordered by two moderately
strong revolving lirae. The lunulae are fine and weakly crescentic.
No ornamentation is known other than fine growth lines and the
selenizone. The specimen measures 5 mm in width and has a pleural
angle of 77 degrees.
Occurrence. — Locality A — one specimen.

Figured specimen. — No. 40513.

Genus EHLERSINA Linsley, n. genus

Ehlersina, n. genus.

Type species. — Here designated as Ehlersina abditinoda, n. sp.

Description. — Moderately large, trochiform, flat-bottomed
nodose gastropods with a slit in the outer lip culminating in a nar-
row selenizone just above the nodose, angular periphery; whorl
profile flat to gently arched, base flattened, minutely phanerom-
phalous in young individuals, crytomphalous (?) in adults; aperture
strongly tapering, oval in outline; parietal, columellar and outer
lips poorly known, apparently thin, not reflected; outer lip appar-
ently with deep, narrow slit culminating in a selenizone just above
the periphery; ornamentation consisting of two rows of nodes, one at
the upper suture and one at the base, the basal row of nodes being
covered by each succeeding whorl.

380 BULLETIN 244

Remarks. — This genus is well represented in the Brunner,
Mond Canada Ltd. quarry and is one of the most abundant of the
large gastropods found there. The phylogeny of this genus is not
completely known, but its closest relative appears to be Euconospira
Ulrich and Schofield (1897) which occurs in Carboniferous and
Permian strata. Consequently I am tentatively placing this genus
in the family Eotomariidae and, hesitantly, in the subfamily Eoto-
mariinae, tribe Ptychomphalides. It differs from Euconospira (and
the closely related Trechmannia Longstaff, 1912) by not having an
incised selenizone and by having coarse, nodose ornamentation.

The generic name Ehlersina is in honor of Dr. George Marion
Ehlers, Professor at the Museum of Paleontology, University of

Michigan.
Ehlersina abditinoda Linsley, n. gen. and n. sp. Pl. 31, figs: Za-e;
Pl. 32, figs. a-c
Description. — Moderately large, trochiform, flat-bottomed,

nodose gastropods with a deep notch in the outer lip culminating
in a slit which generates a narrow selenizone just above the nodose,
angular periphery; whorl profile flat; periphery angular, base flat;
sutures fairly distinct, not incised; base minutely phaneromphalous
in young specimens, seemingly but not certainly becoming cryptom-
phalous in mature individuals; nucleus unknown; columellar, parie-
tal, and outer lips poorly known, apparently thin, not reflected; col-
umellar lip slightly thickened in adults, filling in the narrow um-
bicus; outer lip (judging from growth lines) probably sloping back-
ward from upper suture with strong backward obliquity, which in-
creases gradually from an angle of about 45 degrees to the vertical
at the top of the whorl face to an angle of about 60 degrees near
the selenizone, continuing below the periphery for a short distance
(around the lower row of nodes) with forward obliquity which rap-
idly rounds into a gentle backward obliquity; thence continuing with
a gentle sinuosity, with a shallow forward concavity just inside lower
row of nodes which gradually changes to a gentle forward convexity
to the shallow circumumbilical trough, then becoming more strongly
concave forward on the circumumbilical ridge which acts as a callus;
selenizone narrow bounded by two fine revolving lirae, occurring
about its own width above the angular periphery; lunulae deeply cre-

ANDERDON GAsTROPODS: LINSLEY 381

scentic; depth of selenizone unknown, probably deep; ornamentation
consisting of grewth lines, the revolving lirae bordering the selent-
zone and two rows of nodes; the lower row of nodes occurring at the
periphery and pointing downward, with moderate elongations ex-
tending onto the base; upper row of nodes located at top of whorl,
covering the lower row of nodes of the preceding whorl up to the
level of the selenizone of the preceding whorl; the position and
number of nodes of the upper row determined by the number and
position of the lower row of nodes of the preceding whorl, each node
of the lower row covered by a node of the upper row of the succeed-
ing whorl; nodes apparently absent on first two or three whorls;
nodes first appearing on third whorl] and by the fourth whorl the up-
per row appearing as a continuous scalloped flange breaking into dis-
crete nodes on fifth and subsequent whorls; shell unknown, appar-
ently thin, septae occurring in the earliest whorls, probably not
occurring after the second or third, The holotype, No. 40417, con-
sisting of seven or more whorls, measures 35 mm in height, 41 mm
in width and has a pleural angle of 76 degrees.

Remarks. — This species is abundantly represented in the
Brunner, Mond Canada Company Limited quarry; good specimens
are rare and only two complete specimens (both poorly preserved )
are available to me at present. The molds from the Brunner, Mond
Canada Company Limited quarry are generally lined with calcite
crystals, and the molds of the nodes are usually completely filled
with crystals. Consequently it is difficult to remove the crystal com-
pletely without altering the original shape of the node. Fortunately
one good specimen was found with little or no calcite encrusting the
mold, and other specimens are sufficiently devoid of calcite crystals
to allow a fairly accurate interpretation of the nodal structure. No
single specimen shows all of the characteristics of this species, and
the description above is based upon 12 incomplete specimens each of
which shows one or more structures well.

The trivial name of this species abditinoda is derived from the
Latin abditus meaning “hidden or concealed” and nodus meaning
“knot or swelling” and alludes to the fact that the lower row of
nodes is covered by each succeeding whorl.

Occurrence. — Locality D—50 specimens.

382 BuLLeETIN 244

Types. — Holotype, No. 40417; figured paratypes, Nos, 40418,
40419, 40421, 40423, 40426, 40429; unfigured paratype, No. 40420.
Ehlersina paucinodosa Linsley, n. sp. Pl. 32, figs. 2a-d

Description. — Moderately large, trochiform, flat-bottomed,
nodose gastropods with a deep notch in the outer lip culminating
in a slit which generates a narrow selenizone just above the nodose,
angular periphery; whorl profile gently arched; periphery angular,
base flat; sutures fairly distinct, not incised; base apparently anom-
phalous, possibly cryptomphalous in mature individuals; nucleus un-
known; columellar, parietal and outer lips unknown; outer lip
probably sloping backward from upper suture with strong back-
ward obliquity, which increases gradually from an angle of about
45 degrees to the vertical at the top of the whorl face, to an angle
of about 60 degrees near the selenizone; outer lip of the base with
forward obliquity around the lower row of nodes which rapidly
rounds into a gentle backward obliquity; shape of lip unknown
from this point on, presumably similar to those of the type species;
selenizone narrow, bounded by two fine revolving lirae; position
of selenizone about its own width above the periphery; lunulae
unknown; depth of selenizone unknown; ornamentation consisting
of growth lines, selenizone, and two rows of nodes; the lower row
of nodes poorly known, occurring at the periphery and_ pointing
downward; upper row of nodes located at the top of the whorl,
adpressed onto the lower row of nodes of the preceding whorl up
to the level of the selenizone of the precding whorl; nodes rela-
tively few per whorl, their number and position being determined
by the number and position of the lower row of nodes of the pre-
ceding whorl, each node of the lower row covered by a node of
the upper row of the succeeding whorl; nodes apparently absent
on first two or three whorls; nodes first appearing on third whorl
and by feurth whorl the upper row appear as a continuous scalloped
flange, breaking into discrete nodes on fifth and subsequent whorls;
shell unknown, apparently thin. The holotype, No. 40424, consist-
ing of at least five whorls, is 26 mm in height and 29 mm in greatest
width, and has a pleural angle of 65 degrees.

Remarks. — This species is known from 10 specimens from unit
15 of the Brunner, Mond Canada Ltd. quarry. Only one specimen

Ge

ANDERDON GastTRoOpops: LINSLEY 38

(paratype, No. 40425) shows the base. It is the most complete speci-
ment of the genus as well as this species, but unfortunately it 1s
an internal mold which lacks all of the external features, except
the sparsely distributed nodes. This species differs from the type
species E. abditinoda, n. sp. in that the nodes are fewer and more
widely spaced, and that the whorl profile is gently arched between
the sutures.

The trivial name of this species, pawcinodosa, is derived from
the Latin paucus meaning “few” and nodus meaning “knot or swell-
ing” and refers to the relative paucity of nodes in this species.

Occurrence. — Locality D - 10 specimens.

Types. — Holotype, No. 40424; paratypes, Nos. 40422, 40425,
40427.

Ehlersina ? sp. Pl30} ies 4

Remarks. — One large, incomplete, poorly preserved specimen
was collected from the Brunner, Mond Canada Ltd. quarry that
bears some resemblance to Ehlersina abditinoda, n. sp. but most
probably belongs to a different genus. It is a large, trochiform no-
dose gastropod with a concave whorl profile. The specimen pos-
sesses at least seven whorls, each whorl with an increasingly larger
pleural angle to create a concave whorl profile. There appears to
be only one basal row of nodes and each node continues up the
whorl face to form a rounded, transverse rib, which decreases in in-
tensity toward the upper suture. The growth lines are poorly known
but seem to have a strong backward obliquity and gentle forward
concavity. No other structures can be determined from the speci-
men.

Occurrence. — Locality D - one specimen.

Figured specimen. — No, 40428.

Family LOPHOSPIRIDAE Wenz, 1938
Subfamily LOPHOSPIRINAE Wenz, 1938
Genus LOXOPLOCUS Fischer, 1885
Loxoplocus Fischer, 1885, p. 847.
Type species.— Murchtsonia tropidophora Whiteaves, 1884,
p. 29, by monotypy.

384 BuLLeETIN 244

Subgenus DONALDIELLA Cossmann, 1903
Donaldiella Cossmann, 1903, p. 68.
Type species. — Goniospira filosa Donald, 1902, p. 329, by ob-

jective synonymy.
Loxoplocus (Donaldiella) ? sp. Pl. 33, fig. 4

Remarks. — One specimen was collected from the France Stone
Company quarry which has been tentatively assigned to the sub-
genus Loxoplocus (Donaldiella) Cossmann, 1903. The specimen is
small, only 8 mm in height and 2 mm in diameter. It is a high-
spired shell with many angular whorls and apparently has a shallow
sinus which may or may not culminate in a selenizone generating
slit. If a true selenizone is present then this specimen must be
considered as a species of the Murchisoniacea. The upper whorl
face proceeds flatly downward from the upper suture to the sub-
angular periphery and continues flatly inward below the periphery
to the lower suture. The sutures are deep and angular, and are
inclined at an angle of 62 degrees from the axis of the shell. The
base 1s unknown. The inner and outer lips are unknown, but the
outer lip, judging from poorly preserved growth lines, left the upper
suture with only a slight backward obliquity and apparently a slight
forward concavity, then continues below the selenizone with a
shght forward obliquity.

According to Wenz (1938) and Knight, et al, (1960), this
subgenus has previously been known only from the Ordovician and
Silurian with only one questionable reference from the Silurian
of North America (Wenz, 1938, p. 163), so the identification of
this specimen as Loxoplocus (Donaldiella) must be regarded as
highly tentative.

Occurrence. — Locality A - one specimen.

Figured specimen. — No. 40342.
Family RAPHISTOMATIDAE Koken, 1896
Subfamily RAPHISTOMATINAE Koken, 1896
ZALOZONE Linsley, n. genus

Type species. — Here designated as Zalozone lacunata, n. sp.
Description. — Trochiform gastropods with a low spire and

al

ANDERDON GasTROpPODS: LINSLEY 38

deep, rounded base; a broad, shallow shit culminating at the base
of a deep, V-shaped sinus and generating a broad, undulating
selenizone at the periphery of the whorl; upper whorl face flat-
tened and sloping gradually outward and downward away from the
upper suture; the periphery of the upper whorl face undulating
in rhythm with the selenizone; the outer whorl face gently rounded
and confluent with the lower whorl face; base anomphalous; parie-
tal lip with moderately thickened inductura; outer lip thin; orna-
mentation consisting of fine colabral lines and the fluted selenizone.

Remarks. — This genus is known from only five specimens ob-
tained from the Brunner, Mond Canada Ltd. quarry in Ontario,
Canada. Its diagnostic features are the deep base and the broad
undulating selenizone whose undulations involve the upper whorl
face. It can readily be distinguished from its close relatives Buech-
elia, Raphistoma, and Arizonella in that it possesses the unusual
selenizone. It presents an interesting example of convergence with
the contemporary genus Luciella de Koninck which also possesses
an undulating upper whorl face remarkably like that of Zalozone.
In fact until a specimen of Zalozone was discovered which showed
the base, this new species was thought to belong to the genus
Luciella. However, the deep base and general shape of the aperture
clearly shows that Zalozone belongs to the Raphistomatidae and not
the Luciellidae.

The similarity of this new genus to the Upper Devonian genus
Arastra Stoyanow must also be noted. Again the undulating seleni-
zone of Zalozone permits it to be easily distinguished from Arastra.
However, the similarities between these two genera are sufficiently
great to warrant removing it from the Liospirinae (see Knight,
et al., 1960( p. 1201) and placing it in the subfamily Raphistoma-
tinae. Though the similarities between Arastra and Zalozone would
certainly suggest the possibility of a fairly close kinship, it may
again be a matter of convergence. A close examination of the types
will have to determine whether the selenizone emplacement warrants
their being in the same subfamily or not.

The generic name Zalozone is derived from the Greek zalos
meaning wavey, and zone meaning “belt” or “girdle” referring to
the undulating selenizone.

386 BuLLeTIN 244

Zalozone lacunata Linsley, n. gen., n. sp. Pl. 26, figs. 2a-c;
Pl. 27, figs. 2a-h

Description. — Moderately large, trochiform gastropods with
slightly concave spire profile and a slit or notch in the outer lip
giving rise to a unique undulating selenizone just beneath an unusual
fluted, frilled periphery; each upper whorl face flat or slightly con-
cave between sutures; selenizone and part of outer whorl face ex-
posed below the frill and the suture at the succeeding whorl creating
a sharp shoulder, which may be high in the adult whorls; each suc-
cessive whorl with a slightly larger pleural angle causing the spire
to have a gently concave profile; sutures sharp, deeply incised, fall-
ing well below the selenizone on the outer whorl face; the distance
between the suture and the selenizone becoming increasingly greater
with each successive whorl; nucleus unknown; outer whorl face
falling vertically downward from the selenizone, then rounding
onto the base; base gently rounded, deep, anomphalous, with a
revolving groove occurring about two-thirds the way down the base
from the lower border at the selenizone; columellar lip quite long,
arcuate, slightly thickened, parietal lip poorly known, probably with
a thin parietal inductura; outer lip poorly known, presumably thin
with a notch or slit generating an undulating selenizone just be-
neath the fluted frill; the margin of the lip, based on a study of
growth lines, passing outward from the upper suture to the frill
with a strong backward obliquity and slight forward convexity,
proceeding below the selenizone with slight forward obliquity, slowly
turning to a gentle backward obliquity creating a gentle forward
convexity; growth lines strengthened to form faint collabral orna-
mentation at least on the upper whorl face; selenizone poorly known,
broad and flat, undulating in pace with the frill and in contact
with the trough of the frill; the crest of the frill apparently higher
than the crest of the selenizone thus separating itself from the
selenizone at this point; lunulae poorly known, apparently straight,
not concave or convex, seemingly perpendicular to the borders of
the selenizone; ornamentation consisting of a wide but thin, fluted
frill overhanging the selenizone at the shoulder, and fine collabral
ornamentation on the upper whorl face, sloping from the upper
suture with a strong backward obliquity and gentle forward con-

ANDERDON GASTROPODS: LINSLEY 387

vexity; selenizone and frill not undulating in earlier whorls; un-
dulations appearing gradually as ephebic whorls are reached; orna-
mentation of the base consisting of growth lines and shallow re-
volving groove. Holotype, No. 40388 consisting of 6 (+?) whorls,
measuring 42 mm in width with a pleural angle of 118 degrees.
Pleural angle of earlier whorls about 100 degrees.

Remarks. — Zalozone lacunata, n. sp. differs from Luctella
eliana de Koninck by being anomphalous, in having an undulating
selenizone exposed on each whorl face, and in having ornamentation
that slants obliquely backward, rather than the reticulate pattern
characteristic of that species. It differs from Arastra Stoyanow,
1948 in having a lower, more concave spire, a more acute periphery,
a smoother upper whorl surface and a more finely featured frill
at the periphery, and in possessing the unique undulating seleni-
zone.

The exact nature and significance of the selenizone is not com-
pletely understood at this time because of the lack of good speci-
mens. Indeed the presence and position of a selenizone is still open
to some debate. However, careful examination of the thickened, un-
dulating area underlying the frill has convinced the author that it
truly represents a selenizone. I have been led to this interpretation
because this broad area is bordered by two prominent, revolving
threads and is distinct from the thin frill which overlies this area.
Dr. Roger Batten examined the specimens and concurs with the
author’s opinions (personal communication). The selenizone does
not underlie the undulating border as might be expected in com-
paring these specimens to true members of the genus Luciella, On
the holotype, No. 40388, growth lines proceed right up to the thick-
ened, undulating border with no indication of a selenizone or sinus
of any sort.

A few growth lines apparently cross this undulating border at
widely separated intervals; they are ill-defined, but appear to be
straight and perpendicular to the borders of the selenizone. The fact
that these growth lines are not concave gives some cause to doubt
the interpretation that this undulating border is a selenizone; how-
ever, straight Junulae are present in the selenizone of other genera.

This species is known from four specimens from the Brunner,

388 BuLLeTIN 244

Mond Canada Ltd. quarry. The holotype, the largest specimen, has
most of the base missing. One paratype, No. 40390, shows the base
and the outline of the aperture, though the spire of this specimen
is poorly preserved. This paratype shows no growth lines but does
show one revolving groove on the base. Knowledge of the base
of this species is limited to information available from this one
specimen.

Text-figures 3-5 show a reconstruction of the author’s inter-
pretation of this species based on careful study of all available
specimens.

The trivial name of this species /acunata is derived from the
Latin meaning “fluted” and refers to the fluted frill at the periphery.

Occurrence. — Locality D - four specimens.

Types. — Holotype, No. 40388; paratypes, Nos. 40389, 40390,
40392.

Zalozone sp. cf. Z. lacunata Linsley, n. sp. Pl 26, figs 3:
Pl. .27, fig.. 23:Pl2 28: fis]

Remarks. — One specimen was collected from the Brunner,
Mond Canada, Ltd. quarry which greatly resembles Z. lacuwnata,
n. sp. and is undoubtedly congeneric with it. It differs from Z.
lacunata by being lower spired so that the upper suture falls just
below the selenizone instead of part way down the whorl face. Thus
the concavity at the spire profile is greater, and the steps in the
spire profile are less marked. The sutures are not incised in this
specimen as they are in Z. lacunata. The growth lines on the upper
whorl face do not show as great a degree of backward obliquity
as those of the type species. It seems probable that this is a new
species, but not enough information is presently available to de-
scribe it with any certainty.

Occurrence. — Locality D - one specimen.

Figured specvmen. — No. 40391.

Genus TYLOZONE Linsley, n. gen.

Type species. — Here designated as Tylozone commensurata
Linsley, n. sp.

Description. — Turbiniform gastropods with turreted spire, a
short siphonal canal at base of aperture and a broad, fairly shallow,

ANDERDON GastTRopops: LINSLEY 389

V-shaped sinus in the outer lip culminating in a short slit at the
crest of the shoulder and generating a fairly broad, concave seleni-
zone, periodically raised into nodes; spire profile gently concave,
turreted; upper whorl face rugosely adpressed to outer face of pre-
vious whorl, flattened to concave between upper suture and periph-
ery; outer whorl face flattened between selenizone and revolving
carina; lower whorl face flattened to a coarse circumumbilical ridge;
base narrowly phaneromphalous; parietal lip forming moderately
thick parietal inductura, columellar lip reflected, ending at its base
in a coarse, thickened short siphonal (?) notch, which builds the
circumumbilical ridge; outer lip thin with sinus occurring at upper
shoulder; ornamentation consisting of coarsely nodose selenizone,
coarse, foliaceous growth lines, and in some shells rows of nodes
on the base.

Remarks. — This genus is known from two new species collected
from the Brunner, Mond Canada Ltd. quarry in Ontario. Its diag-
nostic structures are the turreted spire, the nodose selenizone on
the shoulder, the short siphonal canal at the base of the aper-
ture, and the coarse, foliaceous growth lines.

The taxonomic position of this genus is debatable. However, in
the author’s opinion, the genus fits best in the superfamily Pleuro-
tomariacea, family Raphistomatidae, subfamily Raphistomatinae
but apparently on an evolutionary stem other than the progression
marked by Scalites, Raphistoma, Buechelia.

The generic name Tylozone is derived from the Greek tylos
meaning “knot” and zone meaning “belt” or “girdle” referring to
the nodose selenizone.

Tylozone commensurata Linsley, n. sp. Pl. 25, figs. la-f; Pl. 26, figs. la-d

Description. — Moderately large, narrowly phaneromphalous,
turbiniform gastropods with a moderately low turreted spire, a short
siphonal (?) notch in the lower part of the aperture and a broad,
moderately deep V-shaped sinus in the outer lip culminating in a
short slit at the shoulder and generating a fairly broad, concave
selenizone, periodically raised into nodes; spire short, spire pro-
file gently concave; total height of shell approximately equal to
total width; upper whorl face rugose in adults, adpressed against

390 BuLLeTIN 244

side of previous whorl, flat to slightly concave; nodose selenizone
occurring at the outer edge of the whorl face, forming an angular
shoulder: outer whorl face flattened, subvertical, sloping inward
slightly from selenizone to a row of nodes forming a slight angula-
tion at the boundary of the outer whorl face with the base; profile
of base gently concave to a more or less indistinct third row of
nodes midway between outer whorl face and umbilicus, then sharply
concave forming a narrow but distinct circumumbilical groove;
inside umbilical groove a rough, highly thickened, short siphonal
notch forming coarse eee ridge; base narrowly phaner-
omphalous; sutures irregular, adpressed, moderately incised, falling
at, or slightly below, the base of the nodose selenizone, so that a
the three rows of nodes, only the nodose selenizone being exposed
on the whorls of the spire; parietal inductura moderately thick;
columellar lip reflexed, strongly thickened at the base forming a
short siphonal notch which generates a coarse circumumbilical
ridge; outer lip thick, leaving the upper suture with a moderate
backward obliquity which quickly turns to a strong backward
obliquity, resulting in a strong forward convexity; just above the
periphery the outer hp turning backward with extreme obliquity
forming moderately deep V-shaped sinus culminating at its base
in a broad, selenizone-generating notch; outer lip continuing below
selenizone subvertically, with a slight forward convexity, thence
onto the base with a moderate backward obliquity; selenizone
broad, slightly concave; a flat, spiral band in youthful stages,
shghtly undulating by the end of second whorl, with distinct nodes
by end of third whorl; nodes on selenizone large on adult body
whorl, or in some shells absent; selenizone apparently expanding
at the position of the nodes, narrower in between giving the impres-
sion of tremata; lunulae deeply concave; ornamentation consisting
of strongly nodose selenizone, a weaker row of nodes at the junction
of the outer whorl face and the base, and, on adult specimens, a
third, faint row of nodes occurring midway between the outer
whorl face and the umbilicus; other ornamentation consisting of
short, rough, thickened siphonal (?) notch and coarse, foliaceous
growth-lines; shell probably moderately thick, structure unknown;
nucleus poorly known, seemingly simple, smooth and dextral. The

ANDERDON GastTRoPops: LINSLEY 391

holotype, consisting of eight whorls, measures 45.0 mm in height,
45.5 mm in width and has a pleural angle of 113 degrees. Paratype,
No. 40438, consisting of six whorls, measures 18 mm in height, 16.25
mm in width with a pleural angle of 70 degrees. Paratype, No.
40436, consisting of seven whorls, measures 33 mm in height, 31 mm
in width with a pleural angle of 96 degrees.

Remarks. — This species is represented by 43 specimens, many
of which are relatively well preserved, collected from the Brunner,
Mond Canada Ltd. quarry near Amherstburg, Ontario. A number
of these specimens show complete apertures —a_ distinct rarity
among the Anderdon gastropods. Also a number of the specimens
represent immature stages, so that something of the ontogenetic
stages can be learned from them. (In most of the large gastropods
from the Anderdon Limestone, the spires are missing and smaller
shells must be found that are likely to show the character of the
earlier whorls.) The holotype in particular, is well preserved and
is complete except for the base of the circumumbilical ridge.

The selenizone of this species is of special interest for the prob-
lems it creates. On the later ephebic whorls the selenizone is periodi-
cally swollen and raised to form regular, well-developed nodes. How-
ever, on the body whorl of the holotype, No. 40361, nodes are ab-
sent for one-half of a volution but present just before the aperture
is reached. On paratype, No. 40439, the nodes are well developed
on the spire but absent on the body whorl. Where the nodes are ab-
sent the selenizone is a band which alternately undergoes expansion
and contraction, thus resembling tremata that are not completely
closed off. The most probable interpretation of the seemingly un-
usual behavior of the selenizone is that the nodes were removed by
physical or chemical wear and that the expanded “pseudo tremata”
represent the base of a node. This conclusion is substantiated by
the apparent absence of lunulae in the expanded portion of the
selenizone and their presence in the constricted areas. If this ab-
sence of nodes on the body whorl is a natural phenomenon it must
be proven by better material than is now available.

The trivial name, commensurata, 1s derived from the Latin
meaning equidimensional, referring to the equality of the height
and width of this species.

392 BuLLETIN 244

Occurrence. — Locality D - 43 specimens.

Types. — Holotype, No. 40361; figured paratypes, Nos. 40434,
40436, 40438, 40439, 40440; unfigured paratypes, Nos. 40435, 40437,
40441, 40442.

Tylozone turricula Linsley, n. sp. Pl. 26, figs. 5a-c

Description. — Moderately large, narrowly phaneromphalous,
turbiniform gastropods with a high turreted spire, a short siphonal
notch in the lower part of the aperture and a broad, moderately
deep, V-shaped sinus in the outer lip culminating in a short slit
at the shoulder, and generating a fairly broad, concave selenizone,
periodically raised into nodes; spire moderately high, spire pro-
file strongly concave; total height of shell substantially greater than
total width; upper whorl face flat to slightly concave; nodose
selenizone occurring at the outer edge of the whorl face, forming
an angular shoulder; outer whorl face flattened, subvertical, sloping
inward slightly to lower portion of outer whorl face; base joins outer
whorl face with more or less abrupt rounding; base gently rounded
to circumumbilical groove, inside of which occurs a rough, highly
thickened, short, siphonal (7?) canal forming circumumbilical ridge;
base narrowly phaneromphalous; sutures irregular, adpressed, mod-
erately incised, in most specimens situated about halfway down
the outer whorl face; parietal inductura poorly known, apparently
thin; columellar lip reflexed, strongly thickened at the base forming
a short siphonal (?) notch, which generates a coarse circumum-
bilical ridge; outer lip thin, leaving the upper suture with a strong
backward obliquity and moderate forward convexity, forming a sinus
which culminates at the shoulder in a selenizone-generating notch;
outer lip below selenizone poorly known, presumably continuing be-
low selenizone subvertically, with shght forward convexity, thence
onto the base with a moderate backward obliquity; selenizone broad,
slightly concave; a flat spiral band in youthful stages, slightly un-
dulating by end of third whorl, with distinct nodes by end of
fourth or fifth whorl; nodes pronounced on sixth and seventh whorls,
possibly reduced on adult (eighth) whorl; ornamentation consisting
only of strongly nodose selenizone, moderately coarse growth lines
and the thick siphonal (?) canal; shell probably moderately thick,
structure unknown; nucleus unknown. The holotype, consisting of

or

ANDERDON GASTROPODS: LINSLEY 39

eight (?) whorls, is 51 mm in height and 41 mm in width, and has
a pleural angle of 92 degrees. Paratype consisting of eight (7?)
whorls is 59 mm in height and 45 mm in width with a pleural
angle of 70 degrees.

Remarks. — This species is known from five specimens, all of
which are poorly preserved. It can be distinguished from Tylozone
commensurata, n. sp. by being at least 20 per cent taller than it is
wide, whereas 7. commensurata is no more than eight per cent taller
than it is wide. 7. turricula lacks the rows of nodes found on the
base of the body whorl of 7. commensurata. T. turricula is higher
spired with a more acute pleural angle and has the upper suture
located farther down on the outer whorl face of the previous whorl.
In the specimens available, there is no evidence that these variations
form a continuous series between the two species; however, the
study of more and better specimens may show that these shells are
only variants of a single species.

The trivial name turricula is derived from the Latin meaning
“turret” and refers to the high turreted appearance of the species.

Occurrence. — Locality D - five specimens.
Types. — Holotype, No. 40443; paratype, No. 40444.
Tylozone sp. cf. T. turricula Linsley, n. sp. Pl. 26, fig. 4

Remarks. —One specimen was found that consists of a well-
preserved aperture and part of the base of a gastropod which ap-
pears to be a specimen of T'ylozone, n. gen. It certainly is not 7.
commensurata, n. sp.; it may possibly be an example of T. turricula,
n. sp. It is discouraging to find a gastropodal aperture in a fauna
where apertures are so rare and not be able to definitely assign
it to a known species. The lip of this specimen has been broken
for about one-eighth of a whorl; as the result of this damage, the
structure of the lip is not well defined. The aperture has a marked
quadrangular shape. The parietal inductura is thick, the columellar
lip seemingly ended in a short siphonal (?) canal, as in typical
specimens of T'ylozone; the outer lip is thin, with a sharp periphery,
presumably at the location of the selenizone. The upper whorl face
is flat to gently concave, while the outer lip is flattened, and the
base strongly rounded. The base is narrowly phaneromphalous. In
the author’s opinion, it seems that the specimen is a member of

394 BULLETIN 244

the genus T'ylozone; it belongs either to 7. turricula or to an unde-
scribed species.
Occurrence. — Locality D - one specimen.
Figured specimen. — No. 40441.
Family PORTLOCKIELLIDAE Batten, 1956
NODONEMA Linsley, n. genus

Type species.— Here designated as Nodonema granulatum,
n. sp.
Description. —Turbinoform gastropods with flat to arched

whorl profile, bearing a selenizone just below periphery of the
whorl; sutures sharp, moderately deep; base rounded, phanerom-
phalous; columellar lip poorly known, probably slightly thickened;
outer lip thin; ornamentation consisting of strong revolving nodose
lirae which in some adult shells may be absent on the body whorl;
nucleus smooth, simple, dextral.

Remarks. — This genus is typified by the revolving nodose
lirae (whence the name) and the low position of the selenizone.
According to J. Brooks Knight (personal communication to G. M.
Ehlers) this genus is intermediate between Rhineoderma de Kon-
inck, 1883, and Portlockiella Knight, 1945. Nodonema may be dis-
tinguished from Rhineoderma by its narrower umbilicus, the lower
position of the selenizone, and by the lack of the nodular ornamen-
tation within the selenizone. It may be distinguished from Port-
lockiella in having a revolving ornamentation that is more nodular
and transverse growth lines that are less marked. The selenizone is
lower in Nodonema than in Portlockiella and the inner lip of No-
donema shows no evidence of thickening and of filling the um-
bilicus as in Portlockiella.

J. B. Knight suggested the above mentioned generic relation-
ships in 1950 and more recently Roger L. Batten (1956) intro-
duced the family Portlockiellidae and placed in it the genera Port-
lockiella Knight, 1945, Agniesella Cossmann, 1909, Shansiella Yin,
1932, and Tapinotomaria Batten, 1956. This family is differentiated
from other families primarily by the position of the selenizone, which
occurs low on the whorl, but also by the globular (to turreted)
whorls and coarse, revolving ornamentation. The new genus No-

donema has the structural characteristics of members of this fam-

al

ANDERDON GastTRopops: LINSLEY 39

ily and may be distinguished from the above mentioned genera by
having a selenizone which is located lower on the whorl.

Rhineoderma, on the other hand, is now considered by Knight,
et al. (1960) to belong to the family Sinuopeidae Wenz, 1938 and
thus may be considered as being far removed from the Portlockiel-
lidae.

Nodonema differs from the other genera of the family Portlock-
iellidae in having the selenizone located lower on the whorl and a
more well-developed umbilicus. Although poorly known, the colu-
mellar lip is apparently not as greatly thickened (see Pl. 29, fig.
19) as those lips of the other genera in this family. Another unique
feature is that the only known species of Nodonema (N. granu-
latum, n. sp.) is variable, whereas the other species of the family
Portlockiellidae are stable.

Nodonema granulatum Linsley, n. sp. Pl. 28, figs. 3a-m
Rhineoderma sp. Ehlers, Stumm, and Kesling, 1951, pl.3, figs. 25, 27.

Description. — Small, turbiniform gastropods with nodular
revolving ornamentation and a shallow sinus culminating on the
periphery in a notch that gives rise to a selenizone; whorl profile
varying from well rounded to flat between sutures, rounded at the
periphery on the final whorl; sutures sharp, moderately deep; base
rounded, moderately phaneromphalous; columellar lip poorly known,
but apparently slightly thickened and arcurate; parietal inductura
unknown; outer lip unknown, but probably thin, with a moderately
wide, angular sinus culminating at the periphery in a shallow notch,
which gives rise to a wide selenizone bounded by strong, sharp,
sometimes nodose lirae; the margin of the outer lip on the upper
surface sweeping obliquely backward from the upper suture to the
selenizone with slight forward convexity; below selenizone sweeping
obliquely forward with a gentle forward convexity; the selenizone,
which lies just below the periphery, is bounded by two revolving
lirae, with a third intermediate lira midway between the bounding
lirae; lirae may or may not be nodose; lunulae arcuate; ornamen-
tation usually consisting of strong revolving nodose lirae, missing
in some body whorls, in which case, ornamentation consisting of
only selenizone and faint growth lines; revolving lirae occasionally

solid, not broken into nodes in immature specimens; revolving

396 But.ieTin 244

lirae about equal in size, and evenly spaced, with newly originated
lirae arising by intercalation between stronger lirae at irregular
intervals; up to 20 lirae occurring on final (fourth) whorl; growth
lines faint, apparently not always related to the nodes; nucleus
unknown. The holotype is 6 mm in height and 4.25 mm in width,
with a pleural angle of about 58 degrees.

Remarks. — This species is the most abundantly represented
form found in the Anderdon Limestone fauna. Its distinguishing
characteristics are its strongly nodose lirae and small size. The
whorl profile and the general form of the shell is variable. The
pleural angle ranges from 47° to 80°. Although some of this range
is due to the age of the shells (the older ones having a smaller
pleural angle than the young), there is still a wide range. The
whorl profile varies from well rounded from suture to suture with
no shoulder or angulation at the selenizone, to only shghtly arcu-
ate from the upper suture to a subangular periphery and thence
sloping backward sharply to a flattened base. There are all grada-
tions between these two extremes, indicating a case of variation
within the species. In a few shells, the body whorl is smooth and
lacks nodes, although there are nodes present on the earlier whorls.
Only on such body whorls can growth lines be determined. As none
of the specimens have the outer lip preserved, it is only through
the use of the growth lines that the character of the outer lip may
be deduced. The absence of nodes on the body whorl of some shells
seems to be primarily a matter of individual variation of this species
and is not due to erosion of the shell material either before or after
burial; obviously the fine growth lines on such specimens would not
survive any wear that is strong enough to remove the nodes.

Occurrence. — Locality A — 74 specimens; locality B — 424
specimens; locality C — 5 specimens.

Types. — Holotype, No. 40369; figured paratypes, Nos. 40370,
40371, 40372, 40373, 40374, 40375, 40376, 40377, 40379, 40380; un-
figured paratype, No. 40378.

Family GOSSELETINIDAE Wenz, 1938
Subfamily COELOZONINAE Knight, 1956
Tribe COELOZONIDES Knight, 1956
Genus COELOZONE Perner, 1907
Coclozone Perner, 1907 (p. 44).

ANDERDON GaASTROPODS: LINSLEY 397

Type species. — Pleuwrotomaria (Coelozone) verna Perner, 1907
(p. 45) by original designation.

Coelozone fasciata Linsley, n. sp. Pl. 29, figs. 4a, b

Description. — Small, rotelliform gastropods with a low spire
and probably a sinus in the outer lip that culminates at the periph-
ery in a slit or notch giving rise to a selenizone; whorl profile
strongly arched between suture and below selenizone resulting in
subcircular whorl cross section; nucleus not well known, seemingly
normal and dextral; suture sharp, relatively deep, situated adjacent
to the middle of or just below the selenizone of the previous whorl;
base rounded, probably narrowly phaneromphalous; cellular lip un-
known, parietal lip unknown; outer lip unknown, probably cul-
minating at the periphery in a notch or slit of unknown depth which
gives rise to a selenizone; outer lip presumably sloping backward
obliquely with a moderate forward convexity to the selenizone and
continues below the selenizone onto the base with a gentle forward
convexity and obliquity; selenizone concave, depressed between two
fine bordering lirae, the lunulae poorly known, shell unknown, pre-
sumably thin; ornamentation consisting only of fine tranverse
growth lines and selenizone. The holotype is 1.75 mm in height and
3.5 mm in width with a pleural angle of 128 degrees.

Remarks. — This species differs from the type species Coelozone
verna Perner in being about one-tenth as large, in having a larger
pleural angle, stronger collabral ornamentation and a_ narrower
selenizone bounded by threads which are more distinct than those
found on C. verna. Though the base of this new species is not well
known, it would appear to be more narrowly phaneromphalous
than that of the type species. The species is known from a single
specimen collected from the Brunner, Mond Canada Company
Limited quarry near Amherstburg, Ontario.

The trivial name of this species, fasciata, is the Latin word
meaning “envelope with bands” referring to the selenizone occurring
at the perimeter of the shell.

Occurrence. — Locality D — one specimen.

Type. — Holotype, No. 40386.

Genus EURYZONE Koken, 1896

Euryzone Koken, 1896, p. 506.

398 BuLLETIN 244

Type species. — Helcites delphinuloides Schlothiem, 1820, p.
102, by subsequent designation of Perner, 1907, p. 37.

Euryzone petilitornata Linsley, n. sp. Pl. 28, figs. la-g;
Pl. 29, figs. 3a-h

Description. — Small, discoidal to low-spired, turbimiform gas-
tropods with a flattened, subhorizontal upper whorl-face, and prob-
ably with a sinus in the outer lip culminating in a broad, probably
shallow notch which generates a broad selenizone at the juncture
of the upper and outer whorl faces; upper whorl face flattened,
slightly depressed from selenizone to suture; selenizone broad, flat,
located at juncture of upper and outer whorl faces, sloping down-
ward and outward approximately at a 20 degree angle with the
horizontal; outer whorl face with a gentle concave zone as wide as,
and occurring immediately below, the selenizone; whorl face con-
tinuing subcircularly to the umbilical suture; sutures incised, mod-
erately deep, situated about the width of the selenizone from the
lower border of the selenizone of the preceding whorl; nucleus appar-
ently simple, smooth, normally dextral; base rounded, widely
phaneromphalous; parietal, columellar and outer lips unknown;
outer lip probably with a broad, shallow slit generating a flat
selenizone at the juncture of the upper and outer whorl faces;
outer lip presumably leaves upper suture with a moderate backward
obliquity and gentle forward convexity, continuing below the
selenizone subverticaily with a gentle forward convexity; selenizone
bounded by two fine revolving lirae; lunulae crescentic, fine; orna-
mentation consisting only of selenizone and fine growth lines; un-
cooling common, occurring at any stage of development; shell sep-
tate in early whorls. The holotype is 14 mm in width, 6 mm in
height, and has a pleural angle of 146 degrees.

Remarks.— This species is distinguishable from the type
species Huryzone delphinuloides (Schlotheim) by being less than
one-half as large and lower spired, and by having the selenizone
located higher on the outer whorl face.

Uncoiling is fairly common in this species and may take place
at any time after the third volution, or it may not occur at all as in
paratype, No. 40356, which is the largest specimen in the collection.
The disposition of the free whorl is erratic. In the holotype, No.
40462, and paratype, No. 40382, the final free whorl is elevated

ANDERDON GastTRopops: LINSLEY 399

above the level of the penultimate whorl; in paratypes, Nos. 30689
and 40457, the free whorl is in the normal plane of coiling but 1s
deflected outward slightly; in paratypes, Nos. 40459, 40464, the
ultimate free whorl is deflected far away from the preceding whorls
and considerably depressed. In paratypes, Nos. 30673, 40460, the
final whorl is in the normal plane of coiling but is deflected so far
out as to be almost straight. Paratype, No. 40463, is an internal
mold showing widely spaced septa irregularly distributed through-
out a considerable portion of the shell, up to the final whorl.

The trivial name of this species petilitornata is derived from
the Latin petilus meaning “slender” and tornatus meaning “re-
volve” and refers to the slender whorls of this species.

Occurrence. — Locality A—32 specimens; Locality B— 13
specimens; Locality C —55 specimens.

Types. — Holotype, No. 40462; figured paratypes, Nos. 30672,
30673, 30689, 40321, 40356, 40382, 40458, 40459, 40463, 40464;
unfigured paratypes. Nos. 30679, 40457, 40460, 40465, 40516.
Euryzone latitornata Linsley, n. sp. Pl. 29, figs. 2a-c;

Pl. 30, figs. 2a-c

Description. — Moderately small, low-spired, turbiniform gas-
tropods with a broad whorl and with a sinus in the outer lip cul-
minating in a broad, probably shallow notch which generates a broad
selenizone at the juncture of the upper and outer whorl faces; upper
whorl face gently arched, sloping outward and downward from
upper suture of neanic whorls, roundly subhorizontal in ephebic
whorls; broad, flat to arched selenizone located at juncture of upper
and outer whorl faces, sloping downward and outward at about a 45
degree angle with the horizontal; outer whorl face rounded below
selenizone, then sloping flatly inward towards base which is rounded
to the umbilical shoulder; sutures incised, moderately deep, situated
about the width of the selenizone from the lower border of the
selenizone of the preceding whorl; nucleus simple, smooth, normally
dextral; base poorly known, rounded, narrowly phaneromphalous;
umbilical shoulders not pronounced; parietal, columellar and outer
lips unknown; outer lip probably with a broad, shallow slit gen-
erating a flat selenizone at the juncture of the upper and outer
whorl faces; outer lip presumably leaving upper suture with a
moderate backward obliquity and gentle forward convexity to the

400 BuLLeTIN 244

selenizone, continuing below the selenizone subvertically with gentle
forward convexity; selenizone bounded by two fine revolving lirae;
lunulae crescentic, fine; ornamentation consisting only of selenizone
and fine growth lines; uncoiling unknown in specimens available;
septae unlenown but probably present. The holotype 1s 15.0 mm
in width and 8.0 mm in height, with a pleural angle of 162 degrees
for the adult and 116 degrees for the neanic whorls.

Remarks. — This species can be distinguished from Luryzone
petilitornata, n. sp., because it has broader and deeper whorls and,
consequently, fewer whorls in shells of the same diameter. It also
differs from E. petilitornata in having the upper whorl face broad-
ly rounded rather than flat, and from Euryzone pharkidopyndax,
n. sp., in having a smooth base.

This species is known from six specimens collected from the
quarry of the Solvay Process Company at Sibley, Wayne County,
Michigan. Unfortunately, only the holotype shows the base, and
this is poorly preserved. The upper surfaces of all specimens are
well preserved, showing growth lines and a well-formed selenizone.
Paratype, No. 40461, differs from the other specimens in having a
strongly convex selenizone and narrow grooves bordering the seleni-
zone so that the surface of this structure is slightly alee above
the level of the shell instead of being slightly depressed below the
surface as in the holotype and the other paratypes. These differ-
ences are probably a result of the loss of the outer shell layer of this
specimen; thus we have a cast of the surface of the inner shell layer.

The trivial name of this species Jatitornata is derived from
the Latin datus meaning “broad” and tornatus meaning “revolve”
and refers to the broad whosls of this species.

De tee hint B — six specimens.

Types. — Holotype, No. 40466; figured paratypes, Nos. 30687,
40461; unfigured paratype, No. 30688

Euryzone pharkidopyndax Linsley, n. sp. Pl. 29, figs. la-c
Description. — Flatly coiled, widely phaneromphalous gastro-

pods of medium size with a wrinkled base, and probably a shallow
notchlike slit culminating in a selenizone just above the periphery;
upper whorl face gently arched, subhorizontal above the selenizone,
the latter being placed at the juncture of the upper and outer whorl

ANDERDON GastTROPODS: LINSLEY 401

faces; the outer whorl face trending downward and inward from the
selenizone to a strongly rounded, wrinkled cireumumbilical ridge,
thence continuing smoothly inward and upward to the umbilical
shoulder; sutures located slightly below the selenizone of preceding
whorl, moderately incised and moderately deep; nucleus poorly
known, apparently normally dextral; base widely phaneromphalous,
the umbilicus funnel-like and deep; the earlier whorls (first three )
showed a raised spire, but the final whorls becoming more swollen so
that their peripheries extend above the height of the spire; columel-
lar, parietal, and outer lips unknown; outer lip presumably leaving
the upper suture subradially with slight backward obliquity which
may increase near the selenizone; outer lip presumably with a notch
just above the periphery; below the selenizone the outer lip con-
tinues to the collumellar lip with very slight backward obliquity;
selenizone wide, flat to gently convex bounded by two fine revolvy-
ing lirae; lunulae unknown, ornamentation consisting of growth lines
and a rugose circumumbilical keel; shell unknown, apparently thin.
The holotype, consisting of five whorls, is 22.0 mm in width and
11.0 mm in height. Its pleural angle varies greatly with age, that
of the first three whorls being 104 degrees and that of the adult
whorls 162 degrees.

Remarks. — This species is known from only one specimen
which is almost complete and fairly well preserved. However, it may
easily be recognized by two distinctive structures, the swollen adult
body whorl and the wrinkled base. The swollen body whorl is ob-
viously an adult character. Wrinkles, like those on the base, probably
are present on all whorls except the earliest; this is strongly indi-
cated by the fact that the corrugations on the base of the body
whorl are more distinct on the younger than older parts of this
whorl.

Euryzone pharkidopyndax, n. sp. may be distinguished from £.
petilitornata, n. sp. by its wrinkled base, and its whorls are rela-
tively wider and deeper per volution than those of /. petilitornata,
n. sp. It resembles £. latitornata, n. sp. in whorl width and depth
but differs from this species in having a wrinkled base and a swollen
adult body whorl.

The trivial name of this species, pharkidopyndax, is derived
from the Greek pharkidos meaning “wrinkled” and pyndax mean-

402 BULLETIN 244

ing “bottom of a cup or other vessel” and refers to the wrinkled
nature of the base.
Occurrence. — Locality B — one specimen.

Types. — Holotype, No. 40509.
Euryzone ? sp. “A” Pl. 30, figs. 3a, b; Bl 31, figs. fad

Remarks. — A large number of specimens collected from the
Anderdon Limestone of the Brunner, Mond Canada Ltd. quarry are
here designated as Euryzone ? sp. “A.” They are large, discoida',
septate gastropods with a broad shallow sinus in the outer lip that
does not give rise to a selenizone. The upper whorl face 1s flattened,
sloping downward and outward from the upper suture at a 60 to 70
degree angle to the vertical. The outer whorl face is gently arched,
subvertical, joining the upper whorl face with a pronounced angu-
larity. The base is gently rounded, joining the outer whorl face
roundly, and thence gradually rounded to the umbilical suture. The
base is widely phaneromphalous. The upper suture is sharp, strongly
incised, situated one-third to one-half way down the outer face of
the preceding whorl. The umbilical suture is sharp, not incised. The
columellar, parietal, and outer lips are unknown, but the outer lip
aparently leaves the upper suture with a strong backward obliquity
to a broad, shallow sinus at the juncture of the upper and outer
whorl faces. It continues below the sinus with a strong forward
obliquity to the juncture of the outer whorl face and the base where
it reverses itself roundly to a strong backward obliquity with a
marked forward concavity, so that it is subradial by the time it
reaches the umbilical shoulder. The sinus does not generate a seleni-
zone. [he ornamentation consists only of faint growth lines. The
shell is thick, with numerous thick septae occurring irregularly
throughout the shell up to one-half whorls distance from the aper-
ture. The shell structure is unknown. Figured specimen, No. 40407
consists of four (+) whorls; it is 29.5 mm in height and 65.0 mm
in width, and has a pleural angle of 140 degrees.

Because representatives of this species are poorly preserved and
no one specimen shows all of the described characteristics, I have
not established a new species on this form.

This species is limited to the uppermost part of unit 16 (the
uppermost bed) of the Brunner, Mond Canada Ltd. quarry; at some

ANDERDON GastTRopops: LINSLEY 403

places in the quarry it is common. Only Euryzone ? sp. “A” and
Euryzone ? sp. “B” occur at this stratigraphic position. Probably
the most interesting thing about these two species is their unique
mode of preservation at the Brunner, Mond Canada Ltd. quarry.
They occur as natural molds, most of which are poorly preserved.
Evidently their shells were buried in the lime muds deposited during
Anderdon time and uplift and retreat of the sea occurred soon after.
The shells were then dissolved away leaving natural molds which
were then exposed by erosion. The sea, which deposited the over-
lying Dundee Limestone, then invaded the area, and the basal
sediments of this sea filled the molds. Thus these fossils, as they are
now found, have molds and casts of different ages and an erosional
disconformity in each fossil! It is probable that the period of erosion
had much to do with the poor state of preservation of these fossils.

The assignment of these specimens to the genus Euryzone 1s
provisional and is based primarily on the presence of a deep sinus as
revealed by a study of the growth lines. It is possible that they
belong to Straparollus (Euomphalus) rather than Euryzone, but
their final taxonomic position will have to await the acquisition of
better material than is now available.

Occurrence. — Locality E —24 specimens.

Figured specimens. — Nos. 40406, 40407, 40409, 40413.

Euryzone ? sp. “B” Pie Bi sties 4:
Remarks. — Several specimens, obtained from the Anderdon

Limestone of the Brunner, Mond Canada Ltd. quarry, are here
assigned to Euryzone ? sp. “B.” They are large, high turbimform
septate gastropods with a broad shallow sinus in the outer lip
which does not give rise to a selenizone. The upper whorl face is
flattened, sloping downward and outward from the upper suture at
an angle of approximately 45 degrees to the vertical. The outer
whorl face is gently arched, subvertical, joning the outer whorl face
subangularly. The base is gently rounded, joining the outer whorl
face subangularly; the umbilical shoulder is rounded to the umbilical
suture. The base is widely phaneromphalous. The upper suture 1s
fairly sharp, only slightly incised, located at least two-thirds the way
down the outer whorl face of the previous whorl and possibly in-
tercepting the previous whorl at its base. The columellar, parietal,
and outer lips are unknown. The outer lip apparently leaves the

404 BuLLETIN 244

upper suture with a moderate backward obliquity to a broad,
shallow sinus at the juncture of the upper and outer whorl faces,
then continuing below the sinus with a moderate forward obliquity
to the juncture of the outer whorl face and the base where it again
reverses its direction to a strong backward obliquity with a marked
forward concavity. The sinus does not generate a selenizone. The
ornamentation consists only of faint growth lines. The shell is thick
with thick septa occurring irregularly throughout the sheil to a
distance from the aperture equal to one-half a whorl’s length.
The shell structure is unknown. Figured specimen, No. 40408, con-
sists of six (-+-) whorls, is 9.25 mm in height and 40 mm in width,
and has a pleural angle of 75 degrees.

This species is preserved primarily as natural casts composed
of light buff, dolomitic, Dundee Limestone with inclusions of quartz
sand; the casts are within a light bluish-gray, finely crystalline
limestone of the Anderdon Formation. (See the remarks under
Euryzone sp. “A”.) Figured specimen, No. 40408, was far enough
below the erosional surface to escape being filled with Dundee
Limestone; it was filled with a solid mass of calcite crystals that
fortunately fused together to form a natural internal cast and fell
out of the rock when the specimen was cracked open, leaving a
relatively clean external mold. Many other specimens were com-
pletely filled with calcite; unfortunately, however, the fillings be-
came tightly fused to the molds and will not break away cleanly
from the molds. The use of acid to remove the crystalline calcite
from the molds has been to no avail; the molds are in a pure lime-
stone and hence are disolved as rapidly in acid as are the calcite
crystals themselves.

Occurrence. — Locality E — eight specimens.

Figured specimen. — No. 40408.
Tribe PLANOZONIDES Knight, 1956

Genus CATASCHISMA Branson, 1909
Cataschisma Branson, 1909, p. 43.

Type specimens. —Cataschisma typa Branson, 1909, by orig-
inal designation,
Cataschisma (?) sp. Pl. 30, figs. lla, b
Remarks. — One fairly well-preserved incomplete specimen, ob-

ANDERDON GASTROPODS: LINSLEY 405

tained from the Brunner, Mond Canada Ltd. quarry, is provision-
ally assigned to the genus Cataschisma. The gastropod may belong
to an undescribed genus. Unfortunately, the single specimen does
not show the base and consequently its definite taxonomic position
cannot be ascertained until other more complete specimens are
available.

The specimen is moderately large, globose, and naticiform,
with deeply embracing whorls and probably with a broad sinus in
the outer lip culminating just above the periphery of the whorl
that gives rise to a selenizone (pseudoselenizone? ). The whorl pro-
file 1s usually gently arched between the sutures with the body
whorl gently concave for a short distance below the suture, then
gently convex to the selenizone whence it becomes more strongly
convex to form the periphery and presumably continues convexly
to the umbilicus. Each whorl embraces the preceding whorl up to
the lower boundary of the selenizone. The sutures are shallow and
only the presence of the selenizone breaks the even contour of the
whorls. The nucleus and base are unknown. The parietal and
columellar lips are unknown; the outer lip, which is poorly known,
probably extends from the upper suture with a moderate backward
obliquity and continues with no curvature to the location of the
selenizone where there presumably is a shallow, but broad notch.
The selenizone is broad and slightly depressed below the surface
of the shell. The lunulae are unknown; ornamentation or growth
lines are unknown.

Occurrence. — Locality D — one specimen.

Figured specimen. — No. 40506.

Suborder TROCHINA Cox and Knight, 1960
Superfamily PLATYCERATACEA Hall, 1859

Family PLATYCERATIDAE Hall, 1859
Genus PLATYCERAS Conrad, 1840
Platyceras Conrad, 1840, p. 205.

Type species. — Pileopsis vetusta, J. de C. Sowerby, 1829, p.
223, by subsequent designation, Tate, 1869, p. 34.
Platyceras (Platyceras) sp. 1Ale Oily JONES 242,19)

Remarks. — A single platyceratid was found in the Brunner,

406 BuLLeTin 244

Mond Canada Ltd. quarry. It is a poorly preserved specimen, ap-
parently a natural internal mold with a small piece of replaced
shell material clinging to its outer surface. The specimen is an 1r-
regularly horn-shaped gastropod of medium size. The first whorl has
been broken away and lost but was apparently coiled and in con-
tact for a short distance, The last whorl is free, irregularly shaped,
and expands rapidly. There is a broad, slightly concave area on the
inner flanks of the whorl on the right side, and possibly a similar
depression on the left side which is poorly discernable because of the
preservation. Ornamentation is unknown, but it probably consisted
only of growth lines. The aperture 1s poorly known.

Occurrence. — Locality D—one specimen.

Figured specimen. — No. 40504.

Superfamily MICRODOMATACEA Wenz, 1938
Family MICRODOMATIDAE Wenz, 1938
Genus PAGODEA Perner, 1903
Pagodea Perner, 1903, expl. pl. 64.

Type species. — Pagodea concomitans Perner, 1903, expl. pl.
64, by monotypy.
Pagodea falcatinoda Linsley, n. sp. Pl 38s figs Vasa

Description. — Moderately high-spired gastropods with a
strongly oblique outer lip; whorl profile flattened between sutures,
not adpressed; sutures moderately shallow; base gently rounded,
anomphalous; columellar lip thin, arcuate, not reflexed; parietal
lip poorly known, but apparently with a thin inductura; outer lip
poorly shown, apparently thin, unreflexed and with a strong oblique-
ly backward slope away from upper suture, and rounding to an al-
most radial direction on the base; the ornamentation of the neanic
whorls consisting of strong costae; the ephebic whorls have strong
growth lines which intersect at the basal angulation with a revolving
ridge to create fine, crescentic nodes; besides the basal revolving
ridge there is a ridge at the upper border of the whorl and another
slightly above the mid-point of the whorl, all three revolving ridges
being interrupted by the transecting growth lines; shell thin, its
structure unknown. Holotype consists of four ephebic whorls, is 6
mm in height and 4 mm in diameter, and has a pleural angle of 45
degrees.

ANDERDON GAsSTROPODS: LINSLEY 407

Remarks. — This species resembles the type species of Pa-
godea, P. concomitans Perner, in general form and ornamentation
but differs from it in being less than half as large, in not having
the upper part of the whorl adpressed, and consequently having
deeper sutures. The growth lines of P. falcatinoda, n. sp. are less
well developed on the body whorl than are those of P. concomitans.
The revolving ornamentation of P. falcatinoda, n. sp. is stronger than
that of the type species, especially with regard to the nodelike de-
velopment of the basal revolving ridge.

Pagodea falcatinoda apparently is the first representative of
the genus Pagodea from the Middle Devonian strata, and seems to
be midway in development of shell characteristics between the Lower
Devonian Pagodeas and new genus Copidocatomus, n. gen. from the
upper beds of the Anderdon of Brunner, Mond Canada Ltd. quarry.
Copidocatomus shows strong development of the upper and lower
revolving bands although the intermediate band in this genus has
become sufficiently faint so as to be regarded as completely absent.
The base of Copidocatomus is flat and joins the outer whorl face
with a sharp angulation which is emphasized by the lower revolving
ridge. The shell features of Pagodea falcatinoda, n. sp. suggests
Copidocatomus to the author by having stronger revolving orna-
mentation than the Lower Devonian species of Pagodea and also by
having deeper sutures and a somewhat more angular base.

This species is based on only one well-preserved specimen from
the quarry at Sibley, Michigan.

The trivial name of this species, falcatinoda, is derived from
the Latin falcatus, meaning “‘sickle-shaped,” and nodus, meaning
“knot” or “swelling” and refers to the curved nodes at the juncture
of the base and the outer whorl face.

Occurrence. — Locality B—one specimen.

Types. — Holotype, No. 40384.

Genus COPIDOCATOMUS Linsley, n. genus

Type species. — Here designated as Copidocatomus collarus
Linsley, n. sp.
Description. — Small, trochiform gastropods with a flattened

base and sharply angular, narrow shoulder; whorl face flat, bounded

by two revolving lirae, one at the shoulder and one at the base;

408 BuLLeTIN 244

sutures sharply marked but shallow; growth lines thickened, slant-
ing obliquely backward from shoulder to periphery, then continuing
onto the base in a less oblique manner; anomphalous; aperture
unknown; nucleus unknown; ornamentation consisting of growth
lines and two strong revolving lirae, one at the upper edge of the
whorl face and one at the lower edge.

Remarks. — This genus apparently is closely related to and
posibly evolved from the Lower-Middle Devonian genus Pagodea
Perner, 1903, possibly evolving directly from P. falcatinoda, n. sp.
(assuming that P. falcatinoda existed prior to Anderdon time).
Copidocatomus may be distinguished from Pagodea in having a flat
whorl face, sharply incised sutures, a flattened base, and an angular
juncture at the contact of the outer whorl face with the base.

The generic name Copidocatomus is derived from the Greek
kopidos meaning “cleaver” and the Latin catomus meaning “shoul-
der” referring to the sharp revolving lira at the shoulder.

Copidocatomus collarus Linsley, n. sp. Pl. 38, figs. 2a-d

Description. — Small, trochiform gastropods with shallow but
angular shoulders and a flat whorl face; whorl profile extending
flatly outward from suture for a short distance to angular shoulder,
then continuing flatly downward and outward to periphery whence
it turns in sharply to create a sharp ridge before continuing onto
the nearly flat but gently arched base; sutures shallow, but sharply
marked; nucleus unknown; base anomphalous; columellar and
parietal lips unknown, but probably having a strong backward obli-
quity from the shoulder to the periphery with a slight forward con-
vexity, then continuing onto the base with less backward obliquity
and slight forward concavity; ornamentation consisting of rugose,
somewhat irregular growth lines following the pattern of the hypo-
thetical outer lip as described above; other ornamentation consist-
ing of a revolving ridge at the position of the shoulder and a second
revolving ridge at the position of the periphery, so that the flat
whorl face is bounded by these two ridges, giving an angular
appearance to the whorls; slight indication of a third revolving
ridge occuring at midwherl; shell material unknown. The holotype
is 4.5 mm in height and 3 mm in diameter, with a pleural angle of
about 30 degrees.

ANDERDON GaAstTROPODS: LINSLEY 409

Remarks.— This species is known only from one complete
specimen and one incomplete specimen; however, these specimens
show sufficiently diagnostic structures to warrant description. The
primary distinguishing characteristics are the flat whorl face bound-
ed by revolving ridges, which create an angular shoulder (whence
the generic name) and an angular periphery. Other characteristics
of note are the sharply incised but shallow sutures and the rough-
ened growth lines that slope backwards quite obliquely from the
shoulder.

The trivial name collarus is from the Latin meaning “collared”
and refers to the high shoulder and flat whorl face which gives
the impression that each whorl is wearing an old-fashioned high
collar popular during the early 1900’s.

Occurrence. — Locality C — two specimens.

Types. — Holotype, No. 40381; paratype, No. 40383.

Genus MICRODOMA Meek and Worthen, 1867

Microdoma Meek and Worthen, 1867, p. 267.
Pleurotrochus Grabau, 1910, p. 179; Knight and Bridges (iz Shimer and
Shrock), 1944, p. 471.

Type species. — Microdoma conicum Meek and Worthen, 1867.

Microdoma tricarinata (Grabau) Pl. 36, figs. 6a-r

Pleurotrochus bicarinatus nomen nudum Sherzer and Grabau, 1909, p. 550.
Pleurotrochus tricarinatus Grabau, 1910, pp. 179-181, pl. 27, figs. 1, 2;
Wenz, 1938, p. 389, fig. 935; Knight, 1941, pp. 260, 261; pl. 54, fig. 7.

Discussion. — In 1909 Sherzer and Grabau published an anno-
tated fossil list which includes the following entry on page 550:
“Pleurotrochus bicarinatus Grabau manuscript, gen. et sp.; type
similar to the strongly spinose ‘Murchisonia’ of the Upper Siluric
of Gotland, of which several are referred to this genus.” I do not
accept this as an adequate description of the species and thus con-
sider Pleurotrochus bicarinatus Sherzer and Grabau a nomen nudum.
In 1910 Grabau (pp. 179-181) published a description of this new
genus and species with illustrations under the name Pleurotrochus
tricarinatus; thus Grabau’s 1910 description should be treated as the
original description of the genus and species.

Description. — The species was redescribed by Knight (1941,

pp. 260, 261) as follows:

410 BuL_eTIn 244

Small, relatively high-spired, trochiform gastropods with a straight
outer lip and with three revolving carinae bearing nodes or short
spines; whorl profile rather flatly arched; sutures sharply incised,
moderately deep; base unknown but probably somewhat flattened ;
nucleus unknown; columellar and parietal lips unknown; outer lip
seemingly straight and without slit, notch, or sinus; ornamentation on
the earlier whorl known, not the protoconch), seemingly fine lines
of growth alone, on the next whorl relatively strong, sharp, trans-
verse costae which may possibly have been varix-like with a_ ten-
dency toward the formation of a node at the lower end of each costa,
on the next two whorls known, presumably ephebic, the costae have
disintegrated into three revolving rows of nodes, possibly spinelike
in character, the nodes of the lowest row representing the incipient
nodes of the costae of the costate stage the largest and fewest in num-
ber, the nodes of the two upper rows smaller and more numerous, the
middle row of nodes being the weakest; shell structure unknown. The
holotype must have measured about 6 mm. in height originally on the
assumption that it is not merely the tip of a larger shell, and about
3 mm. in width. Its pleural angle is approximately 45 degrees.

Remarks. —Grabau’s holotype is a poorly preserved specimen
with only one-third of a whorl face visible, the base broken and miss-
ing. Subsequent collecting has provided over 125 specimens; most
of these are better preserved than Grabau’s type and have struc-
tures that clearly indicate the morphology of the species, The un-
fortunate preservation of the holotype creates the impression that
the whorl! profile is flatly arched, whereas in most other specimens
the whorl] profile is broadly rounded with a distinct shoulder created
by the uppermost revolving sets of nodes. Except for the irregu-
larities created by the ornamentation, the whorl cross-section 1s
usually subeircular in outline with a flatly arched whorl profile a
relative rarity. The height of the spire is variable with the pleural
angle ranging from 36 to 64 degrees. In general the young speci-
mens tend to have a wider pleural angle than the adult specimens.
The base, unknown in the holotype, is broadly rounded and
minutely phaneromphalous. The ornamentation is variable, con-
sisting only of growth lines in the first whorl which become strong,
varix-like, transverse costae on the ephebic whorl. On the final
whorls of most shells the transverse costae are broken up into three
revolving sets of nodes. The bottom row of nodes is absent in some
specimens whereas in others each node is elongated into a long
Hlangelike protuberance which may continue part way onto the base
of the whorl. Three specimens are well enough preserved to show
growth lines that slope from the upper suture with only a slight

ANDERDON GastTrRopopDs: LINSLEY 411

backward obliquity and a moderate forward convexity. On no
specimen can I find any trace of a fourth “non-spinose or tubercu-
late carina below the lower row of spines” mentioned by Grabau in
his original description (1910, p. 180). He was apparently describ-
ing a line representing the broken base of his holotype. The aperture
is unknown except for the basal part of the outer lip and the
columellar lip, both of which show a slight thickening.

This species bears no relationship to Murchisonia imbricata
Lindstrom as Grabau (1910, p. 181) suggested nor does it have
any affinites to Acanthonema Grabau as Wenz (1938, p. 389) sug-
gested. Now that better specimens are available, it is apparent that
this is congeneric with Microdoma Meek and Worthen, 1867 (p.
269) as proposed by J. B. Knight and Josiah Bridge (im Shimer
and Shrock, 1944, p. 471).

Occurrence. — Locality A — 135 specimens.

Types. — Holotype, No. 12175A; figured hypotypes, Nos.
40393, 40394, 40395, 40396, 40399, 40400, 40401, 40402, 40403,
40404, 40484, 40502; unfigured hypotypes, Nos. 40397, 40398.

Superfamily ANOMPHALACEA Wenz, 1938
Family ANOMPHALIDAE Wenz, 1938
Genus ISONEMA Meek and Worthen, 1866
Isonema Meek and Worthen, 1866B, p. 251.

Types species. — Isonema depressum Meek and Worthen, 1866,
by original designation.

Isonema ? corrugata (Stauffer) Pl. 36, figs. 5a, b
Straparollus corrugatus Stauffer 1909, p. 194, pl. 16, fig. 10.

Remarks. —One specimen was found in the Solvay Process
Company quarry at Sibley, Michigan, which may possibly be con-
specific with the form from the Eversole chert zone of the Columbus
Limestone that Stauffer (1909, p. 194) identified as Straparollus
corrugatus. Stauffer only reported one specimen from the Eversole
Chert and [ have only one specimen from the Anderdon Lime-
stone. [wo small specimens from the France Stone Company quarry,
which may represent young individuals of this species, are subse-
quently described as ? [sonema ? corrugata (Stauffer).

The shell from the Anderdon Limestone is that of a small,
low-spired trochiform gastropod with a moderately oblique outer

412 BuLtvetin 244

lip. The whorl profile is strongly arched between the sutures and
is subelliptical in outline, the base being somwhat more inflated
than the crest of the whorl. The nucleus is poorly shown but appar-
ently is normally dextrai and smooth. The base 1s rounded and the
umbilical region is poorly shown, it apparently is minutely phaner-
omphalous. The columellar, parietal, and outer lips are unknown.
Judging from the collabral ornamentation, the outer lip slopes
obliquely backward from the upper suture with no forward con-
vexity or concavity, The ornamentation consists of fairly well-
developed collabral elements with interspaces of about equal in size
to these elements. Hypotype, No. 40518, is 2 mm in height and
2.75 mm in diameter, and has a pleural angle of 80 degrees.

Stauffer was surely in error in considering his specimen as
belonging to the genus Straparollus. I have tentatively placed this
form in the genus /sonema Meek and Worthen (1866 B, p. 2 aly
though it fits equally well in the genus Straparella Fischer (1885,
p. 829). More positive identification will be impossible until speci-
mens are acquired which show more completely the nature of the
umbilicus and aperture.

Occurrence. — Locality B— one specimen.
Types. — Hypotype, No. 40518.

?Isonema ? corrugata (Stauffer) Pl. 36, figs. 4a-d

Remarks. —'Two specimens were collected from the quarry of
the France Stone Company near Sylvania, Ohio, which I have pro-
visionally assigned to /sonema corrugata (Stauffer). The specimens,
presumably young shells, are small, rotelliform gastropods with no
visible sinus in the outer lip. The whorl profile is strongly arched
between the sutures and broadly rounded at the periphery. The
sutures are sharply incised but shallow. The nucleus is dextral and
unornamented. The base is rounded; although it is unknown whether
an umbilicus is present, the shell probably is minutely phanerom-
phalous. The columellar, parietal and outer lips are unknown; pre-
sumably the outer lip is straight with no sinus or slit. Judging
from the growth lines, the margin of the outer lip slopes backward
from the upper suture with a moderate backward obliquity to the
periphery and continues below the periphery with a gently backward

ANDERDON GAstTROPODS: LINSLEY 413

obliquity. There is no ornamentation other than moderately strong
growth lines.

One of the two specimens, No. 40405, gives the impression of
having some faint revolving ornamentation and may possibly be a
young specimen of Nodonema granulatum Linsley, n. sp., lacking a
selenizone. If a selenizone is present, it is too indistinct to be posi-
tively recognizable. Specimen, No. 40405, is 1.9 mm in height and
2 mm in width, and has a pleural angle of 108 degrees; the other
specimen, No. 40508, has a height of 1.8 mm, a width of 1.8 mm,
and a pleural angle of 109 degrees.

Occurrence. — Locality A—two specimens.

Figured specimens. — Nos. 40405, 40508.

Suborder doubtful (TROCHINA? )
Superfamily PSEUDOPHORACEA S. A. Miller, 1889
Family PSEUDOPHORIDAE S. A. Miller, 1889
Scalaetrochus Etheridge, Jr., 1890, p. 66.

Type species. — Trochus (Scalaetrochus) lindstromi Etheridge,

Jr., 1890, p. 66, by monotypy.

Scalaetrochus fragosus Linsley, n. sp. Pl. 37, figs. la-g
Descritpion. — Large trochiform, anomphalous, (cryptompha-

lous?) gastropods with a flat to slightly concave base and sharply
angular periphery; outer lip sloping downward with a strong back-
ward obliquity and moderate forward convexity; whorl profile
slightly convex just below upper suture, gradually turning to slight-
ly concave, ending in a short frill overhanging the lower suture;
whorl face sloping outward at an angle of about 45 degrees from the
vertical; sutures distinct, deeply incised beneath short overhanging
frill; nucleus unknown; base of shell flat to slightly concave with
angular periphery; anomphalous (cryptomphalous? ); columellar
lip poorly known, apparently slightly thickened, forming an in-
ductura on the base that may be continuous with a thin parietal
inductura; columellar inductura covering umbilicus (if present);
parietal lip unknown; outer lip unknown, apparently leaving upper
suture with moderate backward obliquity gradually changing to a
strong backward obliquity at the periphery, resulting in a moderate
forward convexity; form of lip on base unknown; no selenizone;
of a short flange at the periphery and

ornamentation consisting

414 BuLeTin 244

erowth lines, varying from fine to rugose in intensity; shell material
unknown. Holotype consisting of eight or more whorls, is 58 mm
in height, 65 mm in estimated maximum width, and a pleural angle
of 69 degrees.

Remarks.— This species greatly resembles the type species
Scalaetrochus lindstrémi Etheridge, Jr. (1890, p. 66) in general
form, size, and ornamentation. It differs from S. lindstromi in having
the growth lines more irregular, in having a short, simple flange
which overhangs the sutures and in having the whorl face convex at
the top leading to a sharply incised suture underlying the flange
of the preceding whorl. S. fragosus, n. sp. is known from 18 speci-
mens collected from the Brunner, Mond Canada Company Limited
quarry. Most of the specimens are fragmentary and the molds of
this genus appear to have been especially susceptible, perhaps due to
its large size, to subsequent growth of calcite crystals in the molds,
and this factor combined with the fusion of the large steinkern with
the mold causes the preservation to be poor in most instances.
These are the largest gastropods so far uncovered in the Anderdon
fauna.

The trivial name of this species, fragosus, is Latin meaning
“rough or uneven” and refers to the roughened growth lines.

Occurrence. — Locality D—18 specimens.

Types. — Holotype, No. 40430; paratypes, Nos. 40353, 40363,
40431, 40432, 40433.

Suborder NERITOPSINA Cox and Knight

Superfamily NERITACEA Lamarck, 1809
Family NERITOPSIDAE Gray, 1847
Subfamily NATICOPSINAE §S. A. Miller, 1889
Genus NATICOPSIS M’Coy, 1844
Subgenus N. (NATICOPSIS) M’Coy, 1844
Naticopsis McCoy, 1844, p. 33.
Type species. — Naticopsis phillips: M’Coy, 1844, p. 33, by
subsequent designation of Meek and Worthen, 1866A, p. 364,
footnote.

Naticopsis (N.) pegmihumerosa Linsiey, n. sp. P38; oticseaase

Description. — Medium-sized, naticiform gastropods without a

ANDERDON GastTrRopPops: LINSLEY 415

sinus in the outer lip; whorl profile with a flattened, narrow shoulder
next to the upper suture, then proceeding outward and downward
flatly to the periphery which is rounded and situated high on the
whorl; whorl profile continuing with a gentle rounding to the base;
spire low; base extended, anomphalous; columellar lip gently flaring
in mature individuals; parietal inductura thickened, confluent with
outer and columellar lips with no interruptions; outer lip flaring at
the base, thin at the periphery and thickened at the top; the inner
surface of the upper part of the outer lip with a broad groovelike
area next to the suture which slants downward into the aperture
causing the upper part of the upper lip to be sharp; nucleus un-
known; ornamentation consisting of fine growth lines with a moder-
ate backward obliquity of about 30 degrees; operculum unknown.
Holotype consisting of about four whorls, 20 mm in height, 16 mm in
width, and having a pleural angle of 94 degrees.

Remarks. — This species resembles the type species Naticopsts
phillipsi M’Coy in general form and ornamentation. It differs from
the type species in having a narrower shoulder and in having the
columellar, parietal, and outer lips confluent with each other, and
in having a higher spire.

The trivial name for this species pegmthumerosa is derived from
the Latin pegma meaning “shelf” and humerus meaning “shoulder”
and refers to the flattened shoulder of this species.

The three species of Naticopsis from the Anderdon Limestone
can be distinguished from each other by the following characteris-
tics. N. (N.) opimavoluta Linsley, n. sp. and N. (N.) planifrons
Linsley, n. sp. are both higher spired than NV. (N.) pegmthwmerosa
Linsley, n. sp. NV. (N.) opimavoluta is by far the more robust of the
three species, its whorl height to whorl width ratio being on the order
of 1/1.5, whereas the same ratio for NV. (N.) planifrons is closer to
1/1 and for N. (N.) pegmihumerosa is 1/0.85. N. (N.) pegmi-
humerosa’s main distinguishing structures are the flattened, narrow,
shelflike shoulder and the low spire.

The robust species NV (N.) opimavoluta conforms well with group
1 (“the group of Naticopsis subovatus Worthen”), as suggested by
Knight, (1933B, p 363). NV. (N.) planifrons seems to best fit with

ephebic stages of group 3 (“the group of N. ventricosa,’ Knight

416 BuL_eTIn 244

op. cit.). whereas N. (N.) pegmihumerosa does not fit any of the
three groups of the Pennsylvanian naticopsids suggested by Knight
and probably represents a stock which did not live to Pennsylvanian
time. One specimen of N. (N.) pegmihumerosa has a faint sugges-
tion of nodes and could conceivably represent a descendant of the
form which gave rise to the T'urbonitella-Trachydoma lineage or
more probably represents convergence on the line of N. (Jedria)
Yochelson.

Both N. (N.) opimavoluta and N. (N.) pegmihumerosa [and
presumably N. (N.) planifrons] differ from typical naticopsids in
that the outer lip is completely confluent with the parietal inductura
and columellar lip. They lack the typical “excurrent notch” at the
upper suture, though this may be foreshadowed by the broad,
groove-like area in the uppermost part of the outer lip.

Occurrence. — Locality D — three specimens.

Types. — Holotype, No. 40350; figured paratypes, Nos. 40352,
40360.

Naticopsis (N.) opimavoluta Linsley, n. sp. Pl. 38, figs. 3a-c

Description. — Moderately large, naticiform gastropods with-
out a sinus in the outer lip; whorl profile except for a flat, narrow
shoulder next to the suture; uniformly arched and subcircular in
outline; sutures sharp, moderately incised, situated at or just be-
neath the periphery of the previous whorl; spire relatively high;
base rounded, anomphalous; columellar lip broadly flaring in mature
individuals; parietal inductura thickend, slightly arcurate and com-
pletely confluent with outer and columellar lips; outer lip flaring at
the base, thin at the periphery and slightly reflected at the top
where it becomes confluent with the parietal inductura; nucleus un-
known; ornamentation consisting only of fine growth lines; growth
lines nearly perpendicular to the upper suture with a slight forward
convexity; operculum unknown; shell thick, its structure unknown
but apparently consisting of two distinct layers. Holotype, consist-
ing of four (+) whorls, 21 mm in height and 18 mm in width, and
having a pleural angle of 97 degrees.

Remarks. — This species resembles the type species Naticopsis
phillipsi M’Coy in general form and ornamentation but differs from

ANDERDON GastTrRopops: LINSLEY 417

it in being higher spired, in having a more acute pleural angle, and
in having the columellar lap and the basal and upper portions of the
outer lip flaring. The diagnostic features of NV. (N.) opimavoluta, n.
sp. are the sub-circularity of the whorl profile, the narrowness of the
shoulder and its relatively high spire.

Two specimens of NV. (N.) opimavoluta were collected whose
shells had been replaced by coarsely crystalline calcite. These reveal
the shell to be thick and apparently composed of two layers. One
of these shells was broken approximately on an axial cross-section;
it was ground down and photographed to show what little can be
learned from neritacean cross-sections.

The trivial name of this species, opimavoluta, is derived from
the Latin opimus meaning “well-fed or fat” and voluta meaning
“spiral” and alludes to the rotundity of this species.

Occurrence. — Locality D — eight specimens.

Types. — Holotype, No. 40354; figured paratype, No. 40365;
unfigured paratypes, Nos. 40351, 40357, 40364.

Naticopsis (N.) planifrons Linsley, n. sp. Pl. 38, figs. 4a-d

Description. — Medium-sized, naticiform gastropods without a
sinus in the outer lip; whorl profile flattened between a sharply
rounded shoulder and rounded subangular periphery, continuing
with gentle curvature below the periphery; sutures sharp, deeply
incised, located just above the periphery of the preceding whorl;
spire high; base extended, anomphalous; columellar lip unknown,
presumably flaring in mature individuals; parietal inductura un-
known; outer lip unknown, probably flaring at the base and thin at
the periphery; nucleus unknown; ornamentation consisting of
growth lines, having a slight forward concavity and a backward
obliquity of about 30 degrees; operculum unknown. Holotype con-
sisting of about four whorls, 15 mm in height and 11 mm in width,
with a pleural angle of 86 degrees.

Remarks. — This species resembles the type species Naticopsis
phillipst M’Coy in general form and ernamentation but differs from
it in being higher spired, and having a more acute pleural angle
and the upper whorl face somewhat flattened. It differs from JN.
(N.) opimavoluta, n. sp. in having the whorl height slightly greater

than the whorl width and in having a smaller shell. Its simple, un-

418 BULLETIN 244

ornamented appearance suggests that the species may be more
primitive than N. (N.) subcostata (Goldfuss, 1844) from the De-
vonian of Germany which in turn suggests that N.(N.) plantfrons,
n. sp. is ancestral to the Mississippian naticopsids.

The trivial name of this species planifrons is derived from the
Latin planus meaning “flat or level” and frons meaning “brow or
or forehead” and refers to the flattened upper whorl face of this
species.

Occurrence. — Locality D— seven specimens.

Types. — Holotype, No. 40359; figured paratype, No. 40355;
unfigured paratypes, Nos. 40362, 40366.

Subfamily NERITOPSINAE Gray, 1847
Genus TURBONITELLA de Koninck, 1881
Turbonitella de Koninck, 1881, p. 72.

Type species. — Turbo biserialts Phillips, 1836, p. 226, by sub-
sequent designation, Cossmann, VOUS oe 27s
Turbonitella trunculinoda Linsley, n. sp. Pl. 38, figs. 6a-c

Description. — Small, turbiniform gastropods with a spire of
moderate height; whorl profile sharply shouldered high up on the
whorl and slightly arched on the whorl face below the shoulder;
sutures moderately deep and nearly vertical to form a narrow sutural
probably anomphalous; collumelar lip unknown; parietal lip un-
known; outer lip unknown; growth lines nearly straight with a
slight backward obliquity; other ornamentation consisting of tran-
verse ribs, having strongly developed nodes on the shoulder and
becoming indistinct about halfway down the whorl face. Holotype
consisting of about seven whorls, 5.75 mm in height and 3 mm in
width, with a pleural angle of 66 degrees.

Remarks. — This species is known from three specimens, two
collected in the Solvay Process Company quarry at Sibley, Michi-
gan, and a third poorly preserved specimen from the Brunner,
Mond Canada Company Ltd. quarry. The mode of preservation of
all three spce:mens is unusual and rare as far as the gastropods of
the Anderdon Limestone are concerned. Like the other gastropods,
these specimens are preserved as natural external molds, which are
coated over with a thin lamina of calcite crystals so arranged as
to give the appearance of revolving ornamentation. The lamina is
so thin and evenly applied to the mold that the fine nodes and even

ANDERDON GastTROPODS: LINSLEY 419

the growth lines can be seen. After careful examination of the spect-
mens I am convinced that the only ornamentation of this species
are the nodes and the growth lines.

The crystalline structure of this thin calcite lamina on first
observation appears to be erratically arranged; on further examina-
tion, the crystalline pattern was found to be the same on all three
specimens. This fact leads the author to the conclusion that the
crystalline pattern is that of the original shell material rather than
a haphazard crystal growth; it probably represents the actual crystal
structure at the contact of the inner and outer shell layers of this
species of Turbonitella. The outer shell layer is apparently cemented
to the rock matrix and the mold mentioned above is, therefore,
that of the surface of contact between the inner and outer shell
layers. This hypothesis is supported by the fact that only this
species exhibits this unusual crystal growth.

This species resembles the type species of the genus Turbonitella
biserialis (Phillips) in general form and ornamentation and differs
from the latter in being one-half as high, in having a more acute
pleural angle and more deeply incised sutures, and in Jacking a collar
at the suture line which laps upon the previous whorl. It gives indi-
cation of being more primitive than T'urbonitella biserialis ( Phillips )
in having less conspicuous nodes that are almost vertical, rather
than inclined obliquely backward nodes like those of type species.

This species must represent one of the earliest forms of the
Neritopsinae and presumably is closely related to Naticopsis pegmi-
humerosa, n. sp. Turbonitella trunculinoda, n. sp. differs from Natt-
copsis pegmihumerosa, n. sp. in being considerably smaller, in hav-
ing the nodes much more well developed, and in having a more acute
pleural angle.

Occurrence. — Locality B—two specimens; Locality C— one
specimen.

Types. — Holotype, No. 40367; paratype, No. 40368.

Suborder MURCHISONIINA Cox and Knight
Superfamily MURCHISONIACEA Koken, 1896
Family MURCHISONIIDAE Koken, 1896
Genus MURCHISONIA d’Archiac and Verneuil, 1841
Murchisonia d’Archiac and Verneuil, 1841, p. 154.
Type species. — Muricites turbinatus Schlotheim, 1820. [Mur-

420 BuLLeETIN 244

chisonia bilineata (Dechen), 1832 (p. 533)], by subsequent desig-
nation, Woodward, 1856, p. 147.

Murchisonia (M.) akidota Linsley, n. sp. Pl. 32, figs. 3a-c
Murchisonia sp. Ehlers, Stumm, and Kesling, 1951, pl. 3, figs 22:

Description. — Small, high-spired gastropods with obtusely sub-
angular periphery bearing a selenizone between two revolving lirae;
whorl profile obtusely subangular at the periphery, the whorl face
having a flat to slightly concave surface between the upper suture
and the selenizone and a flat to slightly concave surface between
the selenizone to the lower suture; sutures shallow; nucleus un-
known; base poorly known, slightly flattened with angular revolv-
ing ridge falling at the line of the lower suture; anomphalous or
possibly with an exceedingiy small umbilicus covered by columellar
lip; columellar lip poorly known, apparently slightly reflected; parie-
tal lip unknown; outer lip unknown, but probably with a notch or
slit culminating at the periphery and giving rise to a selenizone,
growth lines indeterminable; selenizone concave between two strong
revolving bordering lirae, the lunulae indeterminable; no orna-
mentation other than lirae bordering selenizone and probably faint
growth lines. Holotype, No. 40322, consisting of 10 whorls (apical
whorls not preserved), 7:25 mm in height and 2.25 mm at greatest
width, with a pleural angle of 15 degrees. Paratype, No. 40319,
consisting of 14 whorls, 7.5 mm in height and 2.5 mm at greatest
width, with a pleural angle of 16 degrees. Paratype, No. 40321,
consists of 16 whorls, 9 mm in height and 2.25 mm at greatest width,
with a pleural angle of 14 degrees. p

Remarks. — This species is like Murchisonia bilineata (Dechen)
in general form and ornamentation but differs from it in being one-
half as large in height, having a slightly more acute whorl profile
at the periphery with the selenizone located nearer the center of
the whorl, and in having a more acute pleural angle. WV. akidota,
n. sp. differs from AZ. trepomena Whidborne (1892) and M. tricincta
Philips (1841) (not Miinster) in being about two-thirds as large,
having more prominent lirae bounding the selenizone, and in having
the sutures more nearly perpendicular to the axis of the shell.

Because of poor preservation, the growth lines are poorly shown,
so little can be deduced about the shape of the lip.

ANDERDON GastTROPoDs: LINSLEY 421

The trivial name akidota is derived from the Greek akidotos
meaning “pointed” and refers to the diagnostic feature of this
species, the pointed spire and small pleural angle.

Occurrence. — Locality C—15 specimens; Locality D— five
specimens.

Types. — Holotype, No. 40322; figured paratype, No. 40319;
unfigured paratype, No. 40320.

Murchisonia (M.) anderdoniae Linsley, n. sp. Pl. 32, figs. 4a-f
?Solenospira? extenuatum (Hall), Grabau, 1910, p. 176, pl. 16, fig. 7.

Description. — Small, high-spired gastropods with subangular
periphery bearing a selenizone between two revolving threads; whorl
profile subangular at the periphery with no shoulder; whorl face
gently convex or nearly flat between the upper suture and the
selenizone, in most specimens with a slight concavity just below
selenizone, and gently convex to the lower suture; suture medium to
deep; nucleus unknown; base rounded, anomphalous, and lacking a
keel at the location of the lower suture; columellar lip poorly
shown, in most specimens slightly thickened or reflexed; parietal lip
poorly shown, apparently with a thin parietal inductura; outer lip
unknown, but probably with a notch or slit culminating at or just
above the periphery and forming a well-marked selenizone; seleni-
zone a concave band situated between two strong, revolving threads;
lunulae unknown; ornamentation consisting only of the selenizone
and possibly faint growth lines too obscure to be of value in deter-
mining the nature of the outer lip.

Holotype, No. 40329, consists of eight whorls, 4.7 mm in height
and 2.5 mm in greatest width, with a pleural angle of 41 degrees.
Other specimens with greatest observed height of 6.5 mm, great-
est observed width of 3.7 mm, as many as eight whorls, and pleural
angles from 25 to 45 degrees.

Remarks. — This species resembles Murchisonia bilineata ( De-
chen) in general form and ornamentation but differs from it in be-
ing about one-half as tall, in having the selenizone located nearer to
a median position between the two sutures of the whorl face, and
in having the selenizone occupying a proportionately larger part
of the whorl face.

M. anderdoniae resembles M. minuta Hall, 1859 (p. 298, pl.

422 BuLLeTIN 244

54, fig. 17); it differs from that species in having a larger pleural
angle and in having fewer but larger whorls in a given space.

This species is apparently an exceedingly variable one. I had
the opportunity to study a population of over 150 specimens and
found the following variations: The pleural angle varies greatly,
ranging from 25 to 45 degrees, with most of thes specimens having
an aie between 30 to 35 degrees; the position of the selenizone
in most specimens is located at the periphery of the whorl, but in
others it is higher on the whorl face.

The upper whorl face of most specimens slopes sharply from
the selenizone toward the upper suture, thus forming a wide angle
(50-60 degrees) with the axis of the shell; in some specimens it
slopes inward less sharply, forming an angle with the axis of about
30 degrees. In the former case, the upper whorl face has a flat
surface and the upper suture is deep; in the latter case, involving a
more acute angle, the upper whorl face tends to be more convex
with a shallower upper suture. These differences have no specific
value; they are variations which are found in all conceivable com-
binations with no apparent tendency toward speciation.

The growth lines on this species are too indistinct to be of much
use in determining the form of the outer lip. From careful observa-
tion of many specimens there is some indication that the growth
lines are similar to those of Murchisonia bilineata (Dechen); the
lines seem to pass downward from the upper suture to the seleni-
zone in a straight line with a moderate backward obliquity, and
from the selenizone to the base in a straight line with a moderate
forward obliquity. Most of the specimens of this species were ob-
tained from the biostromes of the France Stone Company quarry
near Sylvania, Ohio, where the species is common; only a small
number of specimens occur at other localities.

An external mold of a small, high-spired gastropod from the
“Detroit salt shaft,” the first of two salt shafts sunk on the prop-
erty of the International Salt Company at Oakwood, greater Detroit,
Michigan, was identified by A. W. Grabau (1910, p. 176) with
Hall’s Murchisonia extenuata, a species which Grabau reclassified
as Solenospirat extenuatum (Hall). R. S. Bassler (1915, p. 472)

assigned the specimen of S.? extenuatum, described and illustrated

ANDERDON GastTrROpPODsS: LINSLEY 423

by Grabau (1910, p. 176, pl. 16, fig. 7), to Ectomaria? extenuata
(Hall).

The gastropod identified by Grabau as Solenospira? extenuatum
(Hall) is questionably conspecific with Murchisoma (Murchisona)
anderdomae, n. sp. Grabau’s specimen almost undoubtedly belongs
to the genus Murchisonia. Unfortunately casts made from the speci-
men, a natural external mold, show that the original structures of
the exterior of the shell are either so poorly preserved or are miss-
ing as the result of solution that a specific comparison is impossible.
The author suggests that the specimen should be identified as
Murchisonia? sp. (See illustration of specimen, PI. 33, fig. 6.)

It also may be impossible to determine whether Grabau’s speci-
men of Solenospira? extenuatum (Hall) is conspecific with Hall’s
types of Murchisonia extenuata, collected from the Upper Silurian
Manlius Limestone of New York State, because Hall’s types are
poorly preserved and lack definite specific characters.

The specimen of Grabau’s Solenospira? extenuatum (Hall) is
associated with the holoype of Pleurotrochus (—Microdoma) tri-
carinata Grabau in a block of dolomitic-limestone taken from the
“Detroit salt shaft.” Grabau (1910, p. 176) was in error in stating
that this specimen came from the Lucas Dolomite. The fact that
the specimen is associated with P. (=Microdoma) tricarinata Gra-

bau, an excellent guide fossil for the Anderdon Limestone, proves
that this specimen is of Anderdon instead of Lucas age.

The trivial name of this species anderdoniae was chosen be-
cause this is the most abundant species of Murchisonia found in
the Anderdon Limestone.

Occurrence. — Locality A— 159 specimens; locality B— three
specimens; locality C — three specimens.

Types. — Holotype, No. 40329; figured paratypes, Nos. 40323,
40325, 40330, 40331, 40503; unfigured paratypes, Nos. 40326, 40327,
40328.

Murchisonia ? cf. M. (M.) anderdoniae, n. sp. Ply 325nie. 5

Remarks. — Ten specimens were collected from the quarries of
the France Stone Company near Silica, Ohio, and the Solvay Process
Company at Sibley, Michigan, which, by themselves, appear to
belong to a species distinct from 7. anderdoniae, n. sp. However,

424 BULLETIN 244

three or four of these specimens appear to be intermediate between
typical M. anderdoniae, n. sp. and the most robust specimens of
the form under discussion. At present there is an insufficient quan-
tity of well enough preserved material to determine whether this
is a valid species or just a more robust variation of MW. anderdomae.

The shell is small and high-spired, with a subangular periphery
bearing a wide selenizone between two revolving lirae. The whorl
profile is subangular at the periphery and lacks a shoulder. The up-
per whorl face has a flat to slightly concave surface between the
upper suture and the selenizone, Just below the selenizone is a
slight concavity about equal to or slightly greater in width than the
selenizone. Below this concavity the lower whorl face has a gentle
convexity to the lower suture. The sutures are deep, and the nucleus
is unknown. The base is gently rounded and anomphalous. The col-
umellar lip is arcuate and only slightly reflexed. The parietal and
outer lips are unknown, though the outer lip presumably has a
sinus which culminates just above the periphery in a slit or notch
that gives rise to a wide, concave selenizone, bordered by two
moderately strong lirae. Figured specimen, No. 40324, consists of
only three later whorls, is 6 mm in height and 3.5 mm in greatest
width, and has a pleural angle of 38 degrees.

This provisionally identified gastropod is highly reminiscent
of Hormotoma tricarinata Grabau, 1910 (p. 175) (“Homotoma tri-
carinata” of pl. 25, figs. 3, 4). H. tricarinata occurs in the Lucas
Dolomite of the Gibraltar quarry. Neither Grabau’s specimens nor
the Anderdon material presently available to me warrants com-
parison; however, they appear to belong to the same species.

Occurrence. — Locality A—nine specimens; locality B— one
specimen.

Figured specimen. — No. 40324.

Murchisonia (M.) gracilicrista Linsley, n. sp. Pl. 33, figs: ‘5a-c

Description. — Moderately small, high-spired gastropods with
a subangular periphery carrying a selenizone on a slightly raised,
narrow keel; upper whorl face flat to slightly convex between upper
suture and the selenizone and convex between the selenizone and

the base; sutures moderately deep, with whorl faces above and below
the suture intersecting at an angle of about 90 degrees; nucleus

ANDERDON GastTRopops: LINSLEY 425

unknown; base rounded, seemingly but not certainly minutely
phaneromphalous; columellar lip thin, arcuate; parietal inductura
and outer lip unknown; based on configuration of the growth lines,
the outer lip probably with a moderately deep V-shaped sinus, cul-
minating at the periphery in a short notch that generates a seleni-
zone at the periphery of the whorl; the outer lip leaving the upper
suture with marked backward obliquity and moderate forward con-
vexity and continuing below the selenizone with a fairly strong for-
ward obliquity and moderate forward convexity and becoming al-
most subradial at the umbilical shoulder; selenizone of neanic
whorls concave, bounded by two strong revolving lirae which are
raised above the general level of the whorl; selenizone of ephebic
whorls raised above the level of the whorl on a conspicuous keel,
with the two lirae forming indistinct upper and lower boundaries
of the keel: lunulae indistinct; ornamentation other than mentioned
above consisting of irregular, intermittently coarse growth lines.
Holotype, consisting of five later whorls, 38.0 mm in height and
15.5 mm in diameter, with a pleural angle of 21 degrees.

Remarks. — This species somewhat resembles Murchisonia an-
derdonmiae, n. sp. in the configuration of its younger whorls and
differs from this species in having a more rounded whorl profile
and in being at least one and one-half times as large for the same
number of whorls. The adults are distinct from MM. anderdoniae in
the elevation of the selenizone, the roundness of the whorl face, and
larger size of the shell. M. gracilicrista has about the same size as
the type species of Murchisonia, M. bilineata (Dechen) but differs
from the latter in having the selenizone raised on a keel, located
at mid-whorl instead of low on the whorl. The species is known from
10 specimens, only four of which are well preserved.

The trivial name gracilicrista is derived from the Latin gracilis
meaning “slender,” and crista meaning “crest or ridge” and refers
to the raised selenizone.

Occurrence. — Locality A—seven specimens; locality B—
three specimens.

Types. — Holotype, No. 40500; paratype, No. 40501.

Murchisonia (M.) sibleyensis Linsley, n. sp. PIes2higse vac

Description. — Small, high-spired gastropods with rounded peri-

426 BuL_eTin 244

phery, at or just below which is a selemizone between two revolving
lirae; whorl profile rounded; sutures moderately shallow, base round-
ed, anomphalous; columellar lip arcuate, apparently slightly re-
flexed; parietal inductura thin; outer lip unknown, probably with a
moderately deep angular sinus culminating at the periphery in a
short slit that gives rise to a selenizone at mid-whorl or slightly below
mid-whorl; selenizone concave between two faint revolving lirae;
lunulae unknown; ornamentation, in addition to selenizone, pre-
sumably consisting of very fine growth lines. Holotype, No. 40499,
consisting of eight whorls, is 6.2 mm in height and 2.5 mm in width,
with a pleural angle of 21 degrees.

Remarks. — This species resembles the type species Murchi-
sonia bilineata (Dechen) in general form and ornamentation but
differs from it in being about one-third as large, in having a much
narrower selenizone which is located at or slightly beneath mid-
whorl. It also differs from the type species in having a completely
rounded whorl face with no flattened or concave areas other than
the selenizone. This species differs from A/. akidota Linsley, n. sp.
in having fewer whorls, a wider pleural angle, a narrower selenizone,
and a rounded whorl face. It differs from M. anderdoniae Linsley,
n. sp. in having a rounded whorl face and a narrower selenizone
whose bordering costae are much finer. It differs from M/. desiderata
Hall of the Middle Devonian Onondaga Limestone in being much
smaller and in lacking the slightly concave areas below the upper
suture and below the selenizone.

This species is fairly common in the France Stone Company
and Sibley quarries. The preservation of many of the specimens is
relatively good; none of them, however, show the growth lines which
must have been fine. All information concerning the form of the
outer lip is highly speculative and based on the study of other
murchisonids.

This species was given the trivial name sibleyensis because
the best-preserved specimens are from the Sibley quarry and speci-
mens are most abundant at that locality.

Occurrence. — Locality A—17 specimens; locality B—26
specimens; locality C — one specimen.

Types. — Holotype, No. 40499; figured paratype, No. 40496;
unfigured paratypes, Nos. 40334, 40344.

ANDERDON GastTROPODS: LINSLEY 427

Murchisonia ? sp. cf. M. (M.) sibleyensis Linsley, n. sp. Pis2atigws

Remarks. — Many external molds of specimens were collected
that are poorly preserved and lack well-defined structures essential
for specitic identification. The specimens are questionably assigned
to the genus Murchisonia. Though free of an excessive layer of
calcite, the molds show no trace of growth lines nor even a well-
demarcated selenizone. The whorls are rounded much as in JM.
stbleyensis, n. sp. Casts made from some molds show a rounded keel
at the periphery of the whorl that corresponds in position to that
of the selenizone of M. sibleyensis. If better preserved specimens
should be found with growth lines and no selenizone, it is probable
that this form would then be assigned to a loxonematid group; at
present it seems best to regard the molds as poorly preserved speci-
mens of VW. sibleyents.

Occurrence. — Locality A—30 specimens; locality B— one
specimen; locality C — three specimens.

Figured specimen. — No. 40333.

Murchisonia (M.) deludisubzona Linsley, n. sp. Plo 33, figs. 3a,b
Description. — Small, high-spired gastropods with rounded

whorls bearing a selenizone located just below the periphery; whorl
profile arched; whorl cross-section subelliptical, impressed above by
preceding whorl; sutures shallow, inclined to the axis of the shell
at an angle of over 80 degrees; nucleus unknown; base rounded,
anomphalous; columellar lip poorly known, apparently reflexed;
parietal lip with thin inductura; outer lip unknown, probably with
a broad, shallow sinus culminating at the periphery in a notch or
slit, which gives rise to a selenizone; based on the configuration of
the growth lines the margin of the outer lip passing downward from
the upper suture with moderate backward obliquity and little or
no forward convexity, and presumably continuing below the seleni-
zone with moderate forward obliquity; selenizone concave between
two weak bordering lirae; lunulae unknown; ornamentation consist-
ing of selenizone and very faint growth lines: Holotype, No. 40497,
consisting of nine whorls, 8.5 mm in height and 2.8 mm in width,
with a pleural angle of 21 degrees.

Remarks. — ‘This species is known from three specimens from
the Solvay Process Company quarry at Sibley, Michigan. This

428 BuLLeTIN 244

gastropod is primarily interesting because of the light it may throw
on the relationship of Mesocoelia Perner, 1907, to Murchtsonta
d’Archiac and Verneuil, 1841. Mesocoelia is distinguished from Mur-
chisonia by the low position of the selenizone in Mesocoelia, whereas
in Murchisonia the selenizone is located at the periphery about
midway between the upper suture and the base of the whorl. On the
penultimate whorl of Murchisonia deludisubzona, n. sp. the dis-
tance from the upper suture to the selenizone is 1 mm and that from
the selenizone to the lower suture is about 0.25 mm. This low posi-
tion of the selenizone suggests that this species belongs in the genus
Mesocoeha. However, this apparent low position of the selenizone on
the penultimate whorl is due to overlapping of this whorl by the
succeeding ultimate whorl; on the ultimate whorl] of this species the
actual distances are | mm for the upper whorl face and 0.75 mm
from the lower border of the selenizone to the base of the whorl.
Thus it would seem that only consideration of the location of the
selenizone on the ultimate whorl would be a valid criterion for dis-
tinguishing Mesocoelia from Murchisonia and that forms with over-
lapping whorls should be placed with Murchtisonia.

Murchisoma deludisubzona, n. sp. can be distinguished from
other species of Murchisonia by the apparent low position of the
selenizone on the spire whorls and the rounded whorl profile. It
can be distinguished from Mesocoelia obstipisutura Linsley, n. sp.
by the shallowness of the sutures of Murchisonta deludisubzona,
n. sp. by the mid-whorl location of the selenizone on the ultimate
whorl, by its larger pleural angle, and that the sutures are more
nearly perpendicular to the axis than those of Mesocoelia obsti-
pistura, N. sp.

The trivial name of this species deludisubzona is derived from
the Latin deludo meaning “false,” swb meaning “under” and zona
meaning “belt or girdle” and refers to the apparent, but not real,
low position of the selenizone that characterizes this species.

Occurrence. — Locality B—three specimens.

Types. — Holotype, No. 40497; paratype, No. 40498.

Subgenus HORMOTOMINA Grabau and Shimer, 1909

Hormotomina Grabau and Shimer, 1909, p. 651.
Murchisonia (in part) in Knight and Bridges, 1944.

Type species. — Murchisoma maia, Hall, 1861 A, p. 103.

ANDERDON GastTROPODS: LINSLEY 429

Murchisonia (Hormotomina) penduliobesa Linsley, n. sp.
Pl 33% figs) lace
Description. — Shel] moderately small, high-spired, with 11 to
12 whorls; probably with a V-shaped sinus in the outer lip, cul-
minating just below mid-whorl in a notch that gives rise to a seleni-
zone; neanic whorls flattened above and below the selenizone, periph-
ery bluntly angular; early ephebic whorls rounded, somewhat
pendent, profile interrupted only by the selenizone; later ephebic
whorls swollen, not pendent, selenizone no longer breaking up whorl
profile; sutures deep; nucleus unknown; base rounded, anomphalous;
parietal, columellar, and outer lips unknown; based on the configu-
ration of the growth lines, margin of the outer lip probably passing
gentle backward

5
obliquity and gentle forward convexity and below the selenizone

from the upper suture to the selenizone with a

passing onto the base with gentle forward obliquity and gentle
forward convexity; base not well known; selenizone a wide band just
below mid-whorl, on the periphery of the whorl; selenizone bound-
ed by two revolving lirae, with an equally strong median lira mid-
way between the two outer lirae; lunulae rather prominent with
slight curvature; ornamentation consisting of well-defined slightly
raised growth lines. Height of holotype, 13 mm; width of holotype,
5.2 mm; pleural angle 25 degrees.

Remarks. — This species differs from the type species Hormo-
tomina, H. maia (Hall), in being one-fourth as large as the latter
and in having a pendent whorl profile and more prominent growth
lines that are not so oblique as those of Hormotomina maia (Hall).
Description of outer lip is based upon the configuration of the growth
lines.

In 1944, Knight and Bridge (p. 459) placed Hormotomina
Grabau and Shimer in snonymy with Murchtsonia d’Archiac and
Verneuil. After seeing examples of Hormotomina [Murchisonia
(Hormotomina) penduliobesa, n sp.) from the Anderdon Limestone,
Knight suggested (personal communication to G. M, Ehlers) that
Homotomina be recognized as a valid subgenus of Murchisonia. In
the Treatise on Paleozoic Gastropoda (Knight, e¢ al., 1960), this
suggestion was followed.

Although I feel that this interpretation is conservative, [ have

430 BuLLETIN 244

followed the suggestion of considering Hormotomina as a subgenus
of Murchisonia.

From the present limited knowledge of this subgenus it would
seem that the subgenus Hormotomina is an excellent stratigraphic
marker. As previously indicated, one species of the subgenus oc-
curs in the Anderdon Limestone. Murchisonia (Hormotomina) mata
(Hall) is from the Columbus Limestone of Ohio, which rests on
strata of the Detroit River Group in northern Ohio. A third species
[M. (H.) linsleyi Fagerstrom] has been described from the Formosa
Reef Limestone of southwestern Ontario (Fagerstrom, 1961). The
age of the Formosa Reef bioherms is not precisely known though
they appear to be definitely of Detroit River age, presumably of
pre-Anderdon time, (op. cit. p. 45).

Occurrence. — Locality B—two specimens; locality C —two
specimens.

Types. — Holotype, No. 30678; paratype, No. 40495.

Genus CRENULAZONA Linsley, n. genus

Type species. — Here designated as Crenulazona angulata Lins-
ley, n. sp.
Description. — High-spired gastropods of medium size, with

many angular whorls and a V-shaped sinus culminating at the periph-
ery in a slit or notch that gives rise to a crenulated, finely nodose
selenizone; upper whorl profile of ephebic whorls flat to slightly con-
cave; lower whorl face with a broad, markedly concave area just
beneath selenizone in adult whorls; base rounded, narrowly phaner-
omphalous; aperture poorly known; columellar lip slightly thickened
in adult whorls; parietal and outer lips unknown, probably with a
shallow V-shaped sinus culminating at the periphery in a slit or
notch that gives rise to a selenizone; selenizone of neanic whorls
bounded by two fine revolving lirae with a third lira of equal size
situated in the middle of the selenizone of immature specimens; the
middle lira of the selenizone becoming more prominent as mature
whorls are reached until it becomes a large, convexly angular,
raised area between the two, now insignificant, bordering lirae;
intersection of coarse lunulae with thick central lira resulting in
strong crenulated nodes on selenizone of adult whorls; ornamenta-
tion consisting only of selenizone and faint growth lines,

ANDERDON GastrRopops: LINSLEY 431

Remarks.— This genus is characterized by its many angular
whorls and the unusual progressive change in the structure of the
selenizone. The earliest form of the selenizone is not certainly
known; possibly it is bordered by two strong lirae, resembling those
of Murchtsonia anderdomae, n. sp. but differing from the latter in
being more angular and having a more or less pendent whorl profile
so that the ratio of the upper whorl face to the lower whorl face 1s
about two to one. Nevertheless, it would seem that a murchisonid
was ancestral to this genus.

The second phase of the selenizone which begins with the de-
velopment of the third, intermediate lira, brings to mind the genus
Hormotomina Grabau and Shimer although the adult whorl profile
of Hormotomina is decidedly rounded rather than bluntly anguluar
as in Crenulazona. It seems probable that the resemblance between
these two is indicative of their close relationship; however, I hesi-
tate to propose that the highly angular Crenulazona evolved from
a form with as rotund a whorl face as is shown in Hormotomina.
Nevertheless, Murchisonia, Hormotomina, and Crenulazona must
be closely related, presumably with Murchisomia ancestral to the
other two.

The genus Crenulazona resembles Lodonaria Dahmer, 1925
in its general form but differs from this genus in lacking the re-
volving ornamentation characteristic of the latter and apparently 1s
especially distinct in the structure of its selenizone. Unfortunately,
the holotype of Lodonaria is lost (Knight, 1941, p. 176); judging
from a study of a paratype (ibid., pl. 43, fig. 26), the selenizone is
depressed between two strong revolving lirae as contrasted to the
highly raised, crenulated selenizone of Crenulazona. It also differs
from Lodonaria by possessing a definite though shallow sinus.

The generic name Crenulazona is derived from the Latin Cren-
ula meaning “notch” and zona meaning “belt or girdle” and refers
to the crenulated selenizone of this genus.

Crenulazona angulata Linsley, n. sp. Pl. 33, fig. 6;
Pl. 34, figs. la-m; Pl. 35, fig. 2

Description. — Shell medium-sized, high-spired, with numerous
angular whorls and shallow V-shaped sinus culminating at the periph-
ery in a slit or notch of unknown depth that gives rise to a crenu-

432 BuLLETIN 244

lated, finely nodose selenizone;, upper whorl face flat sloping gently
downward towards selenizone at an angle of about 45 degrees with
the vertical: selenizone raised above the projected surface of the
whorl profile; lower whorl face with a broad, markedly concave area
immediately below selenizone, then continuing roundly onto the
base: base rounded, narrowly phaneromphalous; sutures sharp, mod-
erately deep; nucleus unknown; aperture poorly known with no in-
dication of a flaring expansion; columellar lip thin, arcuate, pos-
sibly slightly thickened on final whorl; parietal inductura unknown,
probably thin; outer lip unknown, but judging from configura-
tion of the growth lines leaving upper suture with gentle backward
obliquity and slight forward convexity and continuing below the
selenizone with a forward obliquity of nearly 45 degrees, thus
creating a shallow sinus in the outer lip which probably culminates
at the periphery in a shallow notch or slit that gives rise to a
selenizone; selenizone of immature whorls (approximately the first
five or six) poorly known, possibly forming a broad, flat area at
the periphery bounded by two fairly strong revolving lirae; a third
revolving lirae appearing in the mid-region of the selenizone of the
fifth or sixth whorl and continuing on for three or four succeeding
whorls; lunulae appearing on the eighth whorl, becoming progres-
sively stronger with increase in size of whorl and causing the forma-
tion of fine nodes where they intersect the median lira; with addi-
tion of more mature whorls, flat selenizone becoming progressively
more and more raised to form an angularly convex area between the
two now insignificant bordering lirae; selenizone of adult whorls
angular, rising to a sharp revolving keel; Junulae chevron-like form-
ing small nodes at center of selenizone; ornamentation consisting
only of selenizone and fine lies of growth; shell structure unknown,
shell with septae in early whorls. Holotype, consisting of last nine
whorls, 51 mm in height and 22 mm in diameter, with a pleural angle
of 40 degrees.

Remarks. — This species is especially well represented in unit
15 (‘“back-reef zone”) of the Brunner, Mond Canada Ltd. quarry
where many adult specimens are found. The young specimens of
this species are found predominantly in the biostromal beds of the
Anderdon Limestone at all three localities visited by the author.

ANDERDON GastTROPODS: LINSLEY 433

Apparently the young individuals took refuge among the stromato-
poroids and corals of the biostromes and ventured out onto the
back-reef, lime mud flats only when they reached maturity.

The entire development of the selenizone in this species is not
shown on any single specimen, but is made evident from an examina-
tion of the whorls of a small number of well-preserved specimens.

The trivial name of this species angulata is derived from the
Latin angulatus meaning “with angles” and refers to the angular
adult whorl profile.

Occurrence. — Locality A —three specimens; locality B— six
specimens; locality C—one specimen; locality D— 47 specimens.

Types. — Holotype, No. 30675; figured paratypes, Nos. 30674,
30676, 30677, 40489, 40490, 40491, 40492, 40493, 40494, 40507,
40554; unfigured paratypes, Nos. 40358, 40488.

Genus MESOCOELIA Perner, 1907

Mesocoelia, Perner, 1907, p. 113.
Hormotoma (in part) im Knight and Bridges, 1944, p. 457.
Murchisonia (in part) im Knight, ef al., 1960, p. 1291.

Type species. — Murchisonia (Mesocoelia) janus Perner, 1907,

p. 114.
Mesocoelia obstipisutura Linsley, n. sp. Pl. 35, figs. la-d
Description. — Small, high-spired, many whorled gastropods

with an acute pleural angle; whorls rounded, bearing a selenizone
between two lirae, and situated below the periphery; whorl profile
rounded, sutures deep, inclined to the axis of the shell at an angle
of 65 to 70 degrees; nucleus unknown; base rounded, probably anom-
phalous; columellar lip unknown, probably thin, arcuate; parietal
lip unknown, probably with a thin inductura; outer lip unknown,
apparently with a broad, moderately shallow sinus culminating be-
low the periphery in a notch or slit that gives rise to a selenizone;
the margin of the outer lip passing downward from the upper suture
to the selenizone with a moderate backward obliquity; continuing
below the selenizone with a slight forward convexity; selenizone
very slightly concave between two weak bordering lirae; Junulae un-
known; ornamentation consisting only of selenizone and faint growth
lines. Holotype, No, 40341, consisting of 11 whorls, 11.3 mm in
height and 1.8 mm in width, with a pleural angle of 16 degrees.

434 BuLLeTINn 244

Remarks. — This species is fairly rare in the Anderdon Lime-
stone and the selenizone is often not preserved or only poorly pre-
served so that specimens may easily be confused with Streptacts
Meek, 1872 (p. 173) or with Donaldina Knight, 1933A (p. 57).
Close observation has shown evidence of a selenizone on all except
one specimen; it is presumed that neither of the latter genera are
present and that all of the high-spired forms with rounded whorl
profiles and whose suture is markedly inclined to the axis are speci-
mens of M. obstipisutura.

This species is easily distinguishable from the species of Mur-
chisonia by its rounded whorls, narrow pleural angle, and low posi-
tion of the selenizone.

Mesocoelia may be distinguished from Michela F. A. Roemer
(1854, p. 73) by its distinct selenizone; Michelia has a deep sinus
which does not culminate in a selenizone-generating slit.

The inclination of the sutures to the axis gives the impression
that the shell had been pulled apart and stretched in an axial direc-
tion. The inclination of the sutures is the source of the trivial name
obstipisutura from the Latin obstipus meaning “inclined or oblique”
and sutura meaning “seam.”

Occurrence. — Locality A—nine specimens; locality B— two
specimens.

Types. — Holotype, No. 40341; figured paratypes, No. 40345,
40348; unfigured paratypes, Nos. 40343, 40344, 40346. Figured speci-
men referred provisionally to this species, No. 40347.

Genus CERITHIOIDES Haughton, 1859
Cerithioides Haughton, 1859, p. 282.

Type species. — Cerithioides telescopium Haughton, 1859, p.
282, by monotypy.

Cerithioides incomptum Linsley, n. sp. Pl. 33, figs. 2a-f

Description. — Small, high-spired gastropods with a shallow
sinus in the outer lip probably culminating in a slit that gives rise
to a selenizone; whorl profile only slightly arched; sutures shallow;
base rounded, smooth, anomphalous; parietal and columellar lips
unknown; outer lip unknown but probably with a shallow sinus and
a shallow slit giving rise to a selenizone at the periphery; seleni-

On

ANDERDON GastTrRopoDs: LINSLEY 43

zone fairly low on the whorl; nucleus unknown; ornamentation con-
sisting only of selenizone and exceedingly fine growth lines on neanic
whorls; selenizone bounded by two exceedingly fine lirae, which are
indistinct or absent on adult whorls of many specimens; lunulae
unknown. Holotype consisting of 9 or 10 whorls, 6.25 mm in height
and 2.50 mm in width, with a pleural angle of 29 degrees.

Remarks. — Most of the specimens of this small gastropod were
found in the quarry at Sibley, Michigan; a few were collected from
the Bruner, Mond Canada Ltd. quarry. The selenizone is visible
on the adult whorls of well-preserved specimens; almost all speci-
mens show the selenizone on the earlier whorls. Poorly preserved
specimens, having no visible selenizone and resembling Anematina
Knight (1933A, p. 36), have been assigned to this species. It is
assumed that all similar forms from the Anderdon possessed a seleni-
zone and that its absence is due only to poor preservation.

This species resembles the type species Cerithtoides telescopium
Haughton in general form and character of the selenizone but dif-
fers from it in being about one-tenth as large and in lacking the
revolving ornamentation on the base. C. incomptum, n. sp. is a
variable species with a pleural angle ranging from 25 to 49 degrees.
This variation seems to be primarily due to age, the pleural angle
generally becoming smaller as each successive whorl is added.

The trivial name of this species, incomptum, is from the Latin
meaning “unadorned” referring to the simplicity of the shell.

Occurrence. — Locality B—33 specimens; locality C— five
specimens.

Types. — Holotype, No. 40335; figured paratypes, Nos. 40337,
40338, 40339, 40340; unfigured paratype, No. 40336.

Order CAENOGASTROPODA Cox

Superfamily LOXONEMATACEA Koken, 1889
Family PALAEOZYGOPLEURIDAE Horny, 1955
Subfamily PALAEOZYGOPLEURINAE Horny, 1955
Genus PALAEOZYGOPLEURA Horny, 1955
Palaeozygopleura Horny, 1955, p. 11.
Type species. — Zygopleura alinae Perner, 1907, p. 352, by sub-
sequent designation, Horny, 1955, p. 11.

436 BuLLeTIN 244

Palaeozygopleura sibleyense Linsley, n. sp. Pl. 39, figs. 4a-g
Loxonema sp. Ehlers, Stumm and Kesling, 1951, pl. 3, fig. 24.

Description. — Small, high-spired gastropods consisting of about
nine whorls, with a broad, shallow sinus in the outer lip; whorl] pro-
file rounded: base rounded, anomphalous; columellar lip reflexed,
arcuate; parietal inductura absent; outer lip as shown by growth
lines with a broad, shallow U-shaped sinus, culminating slightly
below mid-whorl; no notch, slit or selenizone; ornamentation prom-
inent, consisting of wide, raised, transverse costae sloping back from
the upper suture at an angle of 15 degrees to the vertical and cury-
ing gently toward the aperture; nucleus consisting of smooth, nor-
mally dextral whorls. Holotype consists of nine whorls measuring 11
mm in height; 3.25 mm in width, with a pleural angle of 17 degrees.

Remarks. — This species resembles the type species Palaeoxy-
gopleura alinae (Perner) in general form and ornamentation but
differs from the type species in that P. sibleyense, n. sp. has round-
ed costae, rather than the sharply ridged costae of the type species.
The interspaces between the costae of the Anderdon form are broader
than those of P. alinae. The sinus occurs lower on the whorl face in
P. stbleyense and its whorls are more inflated.

P. sibleyense most strongly resembles P. vesna Horny and dif-
fers from the latter in that the costae of this new species have a
slight backward slope from the upper suture rather than the forward
slope found in the Czechoslovakian species. Also the costae of
P. vesna appear to be conjoined at the top of the whorl; the costae
of the Michigan form do not show this. P. sibleyense differs from
“Loxonema” (Palaeozygopleura? ) hamiltoniae Hall in being about
one-half as large, in having coarser ornamentation, and a less pro-
nounced sinus.

Paratype, No. 40347 (Pl. 39, fig. 4b) shows a constriction just
below the upper suture similar to that found in some of the sub-
species of Palaeoygopleura alinae (Perner). (Horny, 1955.)

Occurrence. — Locality A—five specimens; locality B— 145
specimens.

Types. — Holotype, No. 30686; figured paratypes, Nos. 40347,
40467, 40468, 40469, 40470, 40471; unfigured paratype, No. 40472.
Palaeozygopleura joanni Linsley, n. sp. Pl. 39}. figs! sack

Description. — Small, high-spired gastropods consisting of about

ANDERDON GastTROPODS: LINSLEY 437

nine whorls, with a broad, shallow to moderately deep sinus in the
outer lip; whorl profile rounded to slightly pendent, occasionally
with slight revolving depression slightly below the upper suture;
base rounded, anomphalous; columellar lip reflexed, arcuate; parietal
inductura absent; outer lip as shown by growth lines with a broad,
shallow to moderately deep U-shaped sinus, culminating at or slight-
ly above mid-whorl; no notch, slit or selenizone; ornamentation
prominent, consisting of many, closely spaced, sharp, raised, trans-
verse costae sloping back from the upper suture at an angle of
about 30 degrees to the vertical and curving back towards the
aperture with a marked convexity; costae extending onto the base;
nucleus consisting of smocth, normally dextral whorls. Holotype,
consists of six adult whorls measuring 11 mm in height, 3.75 mm
in width, with a pleural angle of 15 degrees.

Remarks. — This species differs greatly from the type species
Palaeozygopleura alinae (Perner) by having finer costae that are
considerably more numerous than those of the type species, Also
the costae of P. joanni, n. sp. possess a relatively deep loxonematid
sinus which is lacking in P. alinae.

P. joann, n. sp. most closely resembles P. parallela Horny [P.
(Bojozyga) parallela, Horny in Horny’s 1955 paper] in that P.
parallela has fine, closely spaced costae with a moderately deep
sinus. P. joanni, n. sp. differs from the above mentioned species by
having a wider pleural angle, by having the whorls far more in-
flated, by having deep sutures rather than adpressed whorls, and by
having the sinus occur lower on the whorl face.

P. joann, n. sp. resembles “Loxonema’ (Palaeozygopleurat )
hamultoniae Hall strongly but differs from the latter in having finer,
more numerous costae, and a moderate to strongly concave sinus.
P. joann, n. sp. differs from P. sibleyense, n. sp. by having more
numerous costae which are finer and have a deeper sinus, In gen-
eral the costae of P. joanni, n. sp. extend all of the way onto the
base, whereas the costae of P. sibleyense, n. sp. fade out before the
base is reached.

This species is named in honor of my wife, JoAnn Hoehler
Linsley, in appreciation for the constant encouragement and aid
in writing this paper.

438 BuLLeTin 244

Occurrence. — Locality A—68 specimens; locality B— nine
specimens.

Types. — Holotype, No. 40478; paratypes, Nos. 40473, 40474,
40475, 40476, 40477, 40479, 40480, 40481, 40482.

Subclass OPISTHOBRANCHIA Milne Edwards
Superfamily PYRAMIDELLACEA Phillips, 1875
Family STREPTACIDIDAE Knight, 1931
Genus STREPTACIS Meek, 1872
Streptacis Meek, 1872, p. 173.

Type species. —Streptacis whitfieldi Meek, 1872, p. 173, by
monotypy.
Streptacis (?) sp. Pl. 39, fig. 2

Remarks. — One specimen was found in the France Stone Com-
pany quarry which has been assigned to the genus Streptacis. This
specimen is a small, high-spired, many-whorled anomphalous gastro-
pod with a wide, shallow sinus in the outer lip. The whorl profile is
moderately arched, the sutures shallow. The nucleus is unknown.
The base is rounded, anomphalous. Columellar and parietal lips are
unknown. The outer lip had either an exceedingly shallow sinus or
lacked a sinus. The outer lip must have been almost parallel to the
axis and had only the slightest backward obliquity. On account of
limited knowledge of the nature of the sinus, I question the assign-
ment of this specimen to Streptacis. It could well be a paleozygo-
pleurid, but the establishment of a more definite taxon will have
to await attainment of better specimens. The ornamentation con-
sists of fine costae-like growth lines.

The specimen is 9.5 mm in height, and 2.5 mm in width, and
has a pleural angle of 15 degrees.

Occurrence. — Locality A —one specimen.

Figured specimen. — No. 40544.

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ANDERDON GastTRopops: LINSLEY 439

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442 BuLLeTIN 244

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444 BuLteTIn 244

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PLATES

446 BULLETIN 244

EXPLANATION OF PLATE 25
Figures 1-4 of latex casts

Figs. la-d X 1; figs. le-f K 2; figs. 2-5 X 4

Figure Page

Ll

Tylozone commensurata Linsley, n. gen., N. SP. ees 389
a. Basal view, paratype, UMMP 40434, showing excellent preservation
of circumumbilical ridge suggestive of siphonal notch. b,c,d. Adaper-
tural, oblique apical, and apertural views of holotype, UMMP 40361,
showing moderately thick parietal inductura and pronounced thicken-
ing of columellar lip which forms rough circumumbilical ridge. Ap-
parent absence of nodes on selenizone of body whorl interpreted as a
result of wear, presumably during lifetime of animal. e,f. Oblique
basal view and basal view of paratype, UMMP 40436. Note um-
bilicus, circumumbilical ridge and groove, and moderate development
of a row of nodes at juncture of base and outer whorl face.

Bellerophonstummi-LInsley. M. SPicis scsstee sce kcreeete es a eee oul
a,b. Side view and dorsal view otf holotype, UMMP 40512. c. Dorsal view
of paratype, UMMP 40511.

Tropidodiscus cultricarinatus Linsley, n. sp. ; .... 369
a. Dorsal view of paratype, UMMP 40487. b. Side view of holotype,
UMMP 40485, showing fine, sharp ornamentation,

Tropidodiscus vesculilineatus Linsley, n. Sp. ee 365
a. Side view of holotype, UMMP 30667, showing two surface of the
shell, the lower with strong, broad costae near the umbilicus, the
upper acting as a cover hiding the stronger ornamentation. b, Side
view of paratype, UMMP 30670 with outer shell layer complete, show-

ing only fine growth lines. c. Dorsal view of paratype, UMMP 40483.

Tropidodiscus compticarinatus Linsley, n. sp. OOS
Left side view of holotype, UMMP 30671, one of the few specimens
from the Anderdon Limestone that was not preserved as a natural
mold. Note the small remnant of the high dorsal keel in the lower
right hand of the illustration.

BULL. AMER. PALEONT., VOL. 54 PLATE 25

BuLL. AMER. PALEONT., VOL. 54 PLATE 26

ANDERDON GAsSTROPODS: [INSLEY 447

EXPLANATION OF PLATE 26
All figures of latex casts X 1 except Ie-d and 2a X 2
Figure Page

1. Tylozone commensurata Linsley, n. gen., n. sp. 389
a. Oblique apical view of paratype UMMP 40440, showing lunulae on
selenizone of body whorl which indicate depth of slit. b. Oblique
apical view of paratype, UMMP 40439, showing broken and _ partly
obliterated selenizone of the body whorl and absence of selenizonal
nodes. c,d. Apical and oblique apical views of paratype, UMMP
40438, showing progressive development of selenizone from simple,
parallel-sided early phase, to gradual development of nodes with ac-
companying selenizonal expansion, to a later stage with large nodes
on the ultimate whorl (which represents approximately the anti-
penultimate whorl of the holotype).

2. Zalozone lacunata Linsley, n. gen., n. SDae: 386
a,b,c. Side, oblique apical and apical views of paratype, UMMP 40389.
Note the simplicity of the selenizone on the ephebic whorls as con-

trasted with that of the ultimate whorl.

3. Zalozone cf. Z. lacunata Linsley, n. gen., n. sp. 388
Apertural view of steinkern of UMMP 40391.

4. Tylozone cf. T. turricula Linsley, n. gen., n. sp. 393
Oblique basal view of UMMP 40441.

5. Tylozone turricula Linsley, n. gen., n. sp. 392

a,c. Basal view and side view of holotype, UMMP. 40443, showing high,

turreted spire profile and rounded base. b. Side view of high-spired
paratype, UMMP 40444.

448 BuLvetin 244

EXPLANATION OF PLATE 27
All figures of latex casts
Figure Page

1. Zalozone lacunata Linsley, n. gen., n. Sp. ...... a) Eee SER eee OO
a,b. Oblique basal and apertural views (X2) of paratype, UMMP
40390. Note the circumumbilical groove. c,d,e. Reconstruction of Z.
lacunata (by John R. Chapin). f,g. Side (X2) and apical (X1) of
holotype, UMMP 40388. h. Side view (X4) of paratype, UMMP 40392,
showing two heavy bands bordering selenizone.

2. Zalozone cf. Z. lacunata Linsley, n. gen., n. sp. Seu hte ee OOS
Side view (X2) of UMMP 40391. Note difference in whorl profile
from holotype.

BULL. AMER. PALEONT., VOL. 54 PLATE 27

BULL. AMER. PALEONT., VOL. 54 PLATE 28

Figure

ANDERDON GastTrROpPoDs: LINSLEY 449

EXPLANATION OF PLATE 28
All figures of latex casts X 4 except lg and 2 (X 2) and 3m (X 8)

Page

1. Euryzone petilitornata Linsley, n. sp.................. 398

a,

b,c. Side, apical, and oblique apical views of immature. paraty pe, UMMP
40321. The nucleus is smooth. The selenizone is tilted at a smaller
angle to the axis of the shell than is the case in adult whorls. d.
Apical view of paratype, UMMP 30672, with pleural angle of 180°
and no tendency towards uncoiling. e. Side view of paratype, UMMP
40464, showing considerable outward deflection of the ultimate whorl
with only slight downward depression. f. Apical view of paratype,
UMMP 40458 with slightly depressed ultimate whorl. g. Basal view
of shell interior of paratype, UMMP 40463, showing two-layered shell
and unevenly spaced septa.

2. Zalozone cf. Z. lacunata Linsley, n. gen., n. sp. . 388
Apical view of UMMP 40391.

3. Nodonema granulatum Linsley, n. gen., n. sp. .... ; 395

a. Side view of paratype, UMMP 40378, largest specimen in the collec-

tion. b. Side view of paratype, UMMP 40373. c. Side view of holo-
type, UMMP 40369. Selenizone occupies two inter-liral bands im-
mediately below the heavy lira at juncture of outer whorl face and
base. d. Side view of paratype, UMMP 40375, showing round whorl
profile and coarse nodes. e. Apertural view of paratype, UMMP
40376, showing subcircular whorl profile (contrasted to the pendant
profile of horizontally oriented specimen). f. Side view of paratype,
UMMP 40370, with flattened whorl face. g. Basal view of paratype,
UMMP 40375, showing selenizone. h. Side view of paratype, UMMP
40372, showing fine nodular ornamentation on penultimate whorl, but
with body whorl] almost devoid of nodes. i. Oblique basal view of
paratype, UMMP 40380, showing lunulae and central lira of the
selenizone. j. Side view of paratype, UMMP 40371, an immature
specimen with well-developed nodes on the revolving lirae. k. Side
view of paratype, UMMP 40377, showing revolving lirae without
nodes. m. Side view ot paratype, UMMP 40374, a young specimen
showing the unadorned, normally dextral nucleus and the ephebic
whorl with nodose threads.

450 BuLLeETIN 244

EXPLANATION OF PLATE 29

All figures of latex casts

Figs. 1a,b,c,2a,b,c,3a,e, X 2; figs. 3b,c,d,f,g,h,4a,b, X 4
Figure Page
1. Euryzone pharkidopyndax Linsley, n. sp. . 400
a,b,c. Apical, basal, and side views of holotype, UMMP 40509.

2. Euryzone latitornata Linsley, n. sp. i O99

a,b,c. Side, apical, and basal views of holoty pe, UMMP 40466, showing

width and depth of whorls, rounded upper whorl face, smooth base
and inclination of selenizone.

3. Euryzone petilitornata Linsley, n. sp. ; 398

a.

Oblique apical view of paratype, UMMP 40382, showing ultimate
whorl slightly disengaged and raised above the normal plane of
coiling. b. Oblique apical view of paratype, UMMP 40459, showing
ultimate whorl greatly depressed but not deflected outward. c,e. Apical
and basal views of paratype, UMMP 40356, the largest specimen in
the collection. Its pleural angle approaches 180°, and the shell shows
no tendency toward uncoiling. d,f. Side and apical views of holotype,
UMMP 40462, showing inclination of the selenizone, lunulae, and
uncoiling of last two whorls with the final whorl being. slightly
raised above the plane of the spire. g. Apical view of paratype,
UMMP 30673, showing marked uncoiling of ultimate whorl. h. Oblique
apical view of paratype, UMMP 30689, showing uncoiling and de-
pression of body whorl.

4. Coelozone fasciata Linsley, n. sp. a COO
a,b. Side view and apical view of holotype, UMMP 40386.

BULL. AMER. PALEONT., VOL. 54 PLATE 29

PLATE 30

BULL. AMER. PALEONT., VOL. 54

ANDERDON GASTROPODS: LINSLEY 451

EXPLANATION OF PLATE 30

Figure Page

1G

Cataschisma Sp. ................ , : sre 404
a,b. Side view and apical view (X2) of latex cast of specimen, UMMP
40506, showing bread, shallow, ill-defined selenizone just above periph-

ery of the whorl.

Euryzone latitornata, n. sp. . : ames ae 2 . 399
a,b. Side view and apical view (X4) of latex cast of paratype, UMMP
30687. c. Oblique apical view (X+4) of latex cast of paratype, UMMP
40461. This is a cast of the outer face of the inner shell layer show-

ing incised lirae bordering selenizone.

EUV ZONe ans Dieter tes carrer) ee 2 SRE fc Sie acca: Senctsesecetiien aan e ene 402

a,b. Apical view and basal view (X1) of natural sandstone cast of
UMMP 40406.

Ehlersina ? sp... La ahes:

Oblique apical view (X1) of UMMP 40428, showing concave spire

profile and thick ribs that extend completely across the outer whorl
face.

BuLLETIN 244

EXPLANATION OF PLATE 31

Figs. 2a,b,d,e,3,4, of latex casts; figs. 1a,b,c,d,2a,4, X 1; figs. 2b,c,d,e, X 2;

Figure

fig. 3, X 4

1. Euryzone ? sp. A Be eR Oth RS ee ee eR a be i ee <ce 402
a,b. Oblique apical and oblique basal views of UMMP 40409, showing

a moderately deep sinus at the upper boundary of the outer whorl
face and a shallower sinus at the lower boundary of the outer whorl
face. c. Side view of UMMP 40407. d. Apical view of the interior
of UMMP 40413, showing thickness of shell and irregularly distrib-
uted septae.

2. Ehlersina abditinoda Linsley, n. gen., n. Sp. 0c . 380

a.

Oblique apical view of paratype UMMP 40418. b. Side » view of. para-
type, UMMP 40423, showing narrow selenizone with faint lunulae.
c. Oblique basal view of paratype, UMMP 40426, showing septa in
apical region of shell. d. Basal view of immature specimen, paratype,
UMMP 40419, showing small umbilicus. e. Oblique apical view of
paratype, UMMP 40421, showing upper row of nodes wrapped about
the basal nodes of the previous whorl.

3. Mourlonia ? sp. 378

Side view of UMMP 40513.

4. Euryzone 7eSDs ba , 2403
Side view of UMMP 40408.

BULL. AMER. PALEONT., VOL. 54 PLATE 381

54 PLATE 382

BULL. AMER. PALEONT., VOL.

ANDERDON GastTRoPoDs: LINSLEY 453

EXPLANATION OF PLATE 32
All figures of latex casts
Figs. 1a,b,c,2a,b,c, X 1; fig. 2d X 2; all other figures K 4
Figure Page

1. Ehlersina abditinoda Linsley, n. gen., n. sp. 380
a,c. Side view and oblique basal view of holotype, UMMP 40417. b.
Basal view of paratype, UMMP 40429, showing slight extension of

nodes onto base and callus covering umbilicus.

2. Ehlersina paucinodesa Linsley, n. gen., n. sp. 382
a. Side view of holotype, UMMP 40424, showing the arched outer whorl
face and relative sparseness of nodes. b. Side view of paratype,
UMMP 40427. c. Oblique basal view of paratype, UMMP 40425. d.
Oblique apical view of paratype, UMMP 40422. Note narrow seleni-

zone immediately above adpressed nodes.

3. Murchisonia (Murchisonia) akidota Linsley, n. sp. 420
a. Side view of holotype, UMMP 40322. b,c. Opposing side views of
paratype, UMMP 40319.

4. Murchisonia (Murchisonia) anderdoniae Linsley, n. sp. . 421
a. Side view of paratype, UMMP 40331, a slender specimen. b. Side
view of paratype, UMMP 40330. c. Side view of holotype, UMMP
40329. d. Side view of paratype, UMMP 40325, showing deep sutures
of this specimen. e. Apertural view of paratype, UMMP 40323, show-
ing deep base and slight concavity immediately beneath selenizone. f.

Side view of largest paratype, UMMP 40503.

5. Murchisonia cf. M. (M.) anderdoniae, Linsley, n. sp. 423
Apertural view of UMMP 40324, showing large pleural angle and broad
concave area below selenizone.

6. “Solenospira ? extenuatum” (Hall), Grabau 422

Side view of Grabau’s holotype, UMMP 12175B. This specimen may be

conspecific with Murchisonia (M.) anderdoniae, n. sp. but it is too
imperfectly preserved for generic or specific identification.

7. Murchisonia (Murchisonia) sibleyensis, Linsley, n. sp. . 426

a. Side view of holotype, UMMP 40449, showing round whorl profile

and narrowness of selenizone. b,c. Oblique basal and side views of
paratype, UMMP 40496, showing smooth, rounded base.

8. Murchisonia cf. M. (M.) sibleyensis, Linsley, n. sp. on Oe
Side view of UMMP 40333.

454 BULLETIN 244

EXPLANATION OF PLATE 33
All figures of latex casts
Fig. 6 X 2; all other figures X 4
Figure Page

1. Murchisonia (Hormotomina) penduliobesa Linsley, n. Sp. ...... ... 429

a,b. Opposing side views of holotype, UMMP 30678, showing lunulae

with intermediate lira bisecting them. c. Side view of paratype,
UMMP 40495, a badly worn, but mature and robust specimen.

2. Cerithioides incomptum Linsley, OEIOS ae sic theo
a,f. Side and oblique apical views of paratype, UMMP 40340. b. Side
view of paratype, UMMP 40339. c. Side view of paratype, UMMP
40337. d. Side view of paratype, UMMP 40338, showing faint seleni-
zone on body whorl. e. Side view of holotype, UMMP 40335. Seleni-

zone is barely visible on all whorls.

3. Murchisonia (Murchisonia) deludisubzona Linsley, n. sp. .... 427
a. Side view of holotype, UMMP 40497. Note the rounded, relatively
broad whorls. b. Side view of paratype, UMMP 40498.

4. Loxoplocus (Donaldiella) ? 1 a oeacatee . 384
Side view of UMMP 40342.

5. Murchisonia (Murchisonia) gracilicrista Linsley, n. sp. yeeee . 424
a. Side view of paratype, UMMP 40591. b,c. Side view and oblique basal
views of holotype, UMMP 40500, showing pronounced keel on which

the selenizone is located in the adult whorls.

6. Crenulazona angulata Linsley. n. gen., n. sp. ....... SR SS AOC,
Side view of holotype, UMMP 30675.

BULL. AMER. PALEONT., VOL. 54 PLATE 33

PLATE 34

BULL. AMER. PALEONT., VOL. 54

ANDERDON GastTropPops: LINSLEY 455
EXPLANATION OF PLATE 34
All figures of latex casts
Figs. 1a,b,i,k,m, X 2; figs. 1c,d,e,f,g,h,j, X 4
Figure Page
1. Crenulazona angulata Linsley, n. gen., n. sp. ...... EB
a. Side view of paratype, UMMP 30676. b. Side view of paratype,

UMMP 30674, well-preserved specimen showing the character of the
selenizone in early ephebic whorls. Note that the central lira has broken
nodes. c. Side view of paratype, UMMP 40507, showing the central lira
of the selenizone of neanic whorls. d. Side view of paratype, UMMP
40493, showing structure of the selenizone of a middle or late ephebic
whorl. Note how the central selenizonal lira has become a raised,
angular central area, with long crenulations derived from thickened
lunulae. e. Side view of paratype, UMMP 40491, provisionally as-
signed to this species as representative of the earliest whorls of this
species. f. Side view of paratype, UMMP 40492, showing progressive
development of the selenizone from three-banded late neanic stage
to early ephebic stage with crenulated central lira. g. Side view of
paratype, UMMP 40554, showing change in selenizone from neanic
to ephebic whorls. h. Side view of paratype, UMMP 40494, showing
three-banded neanic selenizone. i. Side view of paratype, UMMP
30677. j. Side view of paratype, UMMP 40490, showing development
of the selenizone from three-banded neanic stage to a relatively mature
ephebic stage having a well-crenulated selenizone. k,m. Oblique basal
view and side view of paratype, UMMP 40489, showing narrow
umbilicus and reflected inner lip.

456 BULLETIN 244

EXPLANATION OF PLATE 35
All figures of latex casts
Fig. 2X 2; all other figures X 4
Figure Page

1. Mesocoelia obstipisutura Linsley, n. sp. .... Ss ee 433
a. Side view of holotype, UMMP 40341, showing ty pical low position of
the selenizone and inclination of the sutures. b. Side view of para-
tvpe, UMMP 40347. This specimen has the selenizone in the low
position but lacks the inclination of the sutures. c. Side view of para-

type, UMMP 40348. d. Side view of paratype, UMMP 40345.

2. Crenulazona angulata, Linsley, n. gen., nN. SP. oo... eee 432
Basal view of holotype, UMMP 30675, showing ‘umbilicus and thickened
columellar lip.

3. Straparollus (Serpulospira) diversiformis eel n. Sp.
morphotype ‘A” ues ne I SOS
a,b. Apical view and basal view of paratype, -UMMP 30682, showing
uncoiling already present in this immature specimen. c,d. Apical view
and oblique apical view of paratype, UMMP 40445, showing con-
spicuous uncoiling in one plane. e. Basal view of paratype, UMMP
40446.

4. Straparollus (Serpulospira) diversiformis Linsley, n. sp.
morphotype “B” . 2 Pits. 33
a,b. Apical view and basal view of holotype, UMMP 30680, showing
little uncoiling. Note the strong resemblance to 8S. (Straparollus) in
regards to the lack of uncoiling. c. Basal view of paratype) UMMP
40448. d. Apical view of paratype, UMMP 40449, showing well-de-
fined growth lines.

5. Straparollus Serpuieee a) diversiformis Linsley, n. sp.
morphotype ‘‘C” ; Ste dt inh Oe eee 373
a,b. Oblique apical view and apical view of paratype, UMMP 40452.
cde. Apical view, oblique apical view, and basal view of paratype,
UMMP 30684, showing whorls that are strongly depressed but not de-
flected outward.

6. Straparollus (Serpulospira) diversiformis Linsley, n. sp.
morphotype “D” ..... See ee eee ee ee 373
a. Basal view of paratype, UMMP 40453. b,c. Apical view and ‘oblique
apical view of paratype, UMMP 40454, showing whorls that are
greatly deflected and depressed. d. Apical view of paratype, UMMP
30681.

PLATE 35

BuLL. AMER. PALEONT., VOL. 54

PLATE 36

BULL. AMER. PALEONT., VOL. 54

ANDERDON GASTROPODS: LINSLEY 457

EXPLANATION OF PLATE 36
All figures of latex casts

Figs. 1a,b,2,3, X 1; figs. +a,b,c,d,6b, X 8; all other figures X 4

Figure Page

1. Straparollus ? (Evomphalus) sp. Cok eee eee eee eee Sut
a,b. Apical view and basal view of UMMP. 40416.

2. Straparollus ? (Evomphalus) sp. A. yeas etc ee eee OO
Apical view of UMMP 40414.

3. Straparollus ? (Evomphalus) sp. B......, 376
Apical view of UMMP 40415.

4. ?Isonema ? corrugata (Stauffer) ..0..0000..ccccccccccccccccceccccceee eee ek ee 412
a,b. Apical view and side view of UMMP. 40405. c,d. Side view and

apical view of UMMP 40508.

5. Isonema ? corrugata (Stauffer) . ot Sa eee NY 411
a,b. Side view and apical view of UMMP 40518.

6. Microdoma tricarinata (Grabau) ........00000......cccccccceeeeceeeeeeneeeeeees 409

a. Oblique basal view of hypotype, UMMP_ 40484, a ~ specimen whose
lower row of nodes is slightly developed. Note the narrow umbilicus
and the thickened columellar and lower outer lip. b,c. Side views
of immature hypotype, UMMP 40400. d. Side view of hypotype,
UMMP 46401. e,k. Apertural view and oblique basal view of hypo-
type, UMMP 40402, showing subcircular whorl profile, small um-
bilicus, and wide shoulder formed by uppermost row of nodes. f. Side
view of hypotype UMMP 40399, a small specimen showing a rela-
tively large, smooth nucleus. g. Side view of hypotype, UMMP
40403. This immature specimen demonstrates well the transition from
a smooth nucleus to the varix-like costae of the neanic whorls and the
disintegration of these costae into rows of nodes. Note the elongated
lower row of nodes. h. Side view of Grabau’s holotype, UMMP
12175A, a specimen lacking the base. i. Side view of hypotype, UMMP
40404, a specimen lacking the lowest row of nodes. j. Side view of
hypotype, UMMP 40395. m,n. Side view and oblique basal view of
hypotype, UMMP 40394, a specimen with the lower row of nodes
greatly elongated and extended onto base. p. Side view of hypotype,
UMMP 40396. q. Oblique apical view of hypotype, UMMP 40393,
showing heavy growth lines near aperture. r. Side view of hypo-
type, UMMP 40502, a relatively large specimen with deep sutures.
The lowest row of nodes is missing on all whorls.

458 BULLETIN 244
EXPLANATION OF PLATE 37
All figures except 2a,b of latex casts
Figs. la,b,d\e,f,¢, X 1; figs. 1¢2ajb, X 2
Figure Page
J ‘Scalaetrochusafragosus. linsley sine Spe) tne eee 413

a. Side view of paratype, UMMP 40432, showing thick, irregularly
spaced growth lines. b. Side view of paratype, UMMP 40353. c.
Oblique basal view of paratype, UMMP 40363, a poorly preserved
specimen which nevertheless shows the characteristics of the flat base.
d. Side view of paratype, UMMP 40431, showing well-preserved
growth lines on the ultimate whorl. e. Side view of holotype, UMMP
40430, showing concave spire profile and overhanging base. f,g. Op-
posing side views of paratype, UMMP 40433, showing overhanging
frill and flat base.

2. Platyceras (Platyceras) sp. ... stony ef ern se OD
a,b. Front view and side view of UMMP 40504.

BULL. AMER. PALEONT., VOL. 54 PEAT ERT

/

SETS

si

Buu. AMER. PALEONT., VOL. 54 PLATE 388

ANDERDON GASTROPODS: LINSLEY 459

EXPLANATION OF PLATE 38
All figures of latex casts except figure 3c
Figs. 3a,b,c,4a,b,c,5a,c, X 2; figs. 1a,2a,b,c,d,5b,6a,b,c, X 4; fig. lb, X 8
Figure Page

1. Pagodea falcatinoda Linsley, n. sp. . =i 9r 40G
a,b. Oblique basal view and side view of holoty pe, 6) MMP 4 40384, show-
ing thin apertural lip, absence of an umbilicus, and sickle-shaped
nodes at the periphery. The lighting on fig. 1b emphasizes the growth
lines, but fails to show the prominence of the middle, revolving lira.
Note carinate ornamentation of the neanic whorl.

2. Copidocatomus collarus Linsley, n. gen., n. sp. . 408
a,c,d. Opposing side views and oblkane basal view Saks holoty pe, UMMP
40381. The primary light of fig. 2a was placed at the lower right to
emphasize whorl profile and sharp revolving carinae bordering the
outer whorl face. The primary light of fig. 2c was placed at the lower
left to emphasize growth lines. b. Side view of paratype, UMMP
40383, showing sharp angulations bordering flattened outer whorl

face.

3. Naticopsis (Naticopsis) opimavoluta Linsley, n. sp. .... 416
a,b. Side view and apertural view of holotype, UMMP 40354. c. Cross-
section of paratype, UMMP 40365. Note how the two shell layers
thicken at the apertural shoulder and are separated from each other

(by solution ?).

4. Naticopsis (Naticopsis) planifrons Linsley, Nn: Sp: 417
a,c. Oblique apical view and side view of holotype, UMMP 40359, ‘show-
ing sharp, deeply incised sutures, and the absence of a pronounced
shoulder. b,d. Oblique apical view and side view of paratype, UMMP

40355,

5. Naticopsis (Naticopsis) pegmihumerosa Linsley, mn. sp. 414
a. Apertural view of holotype, UMMP 40350, showing wide shoulders,
deep body whorl, and thickened aperture. b. Oblique apical view of
paratype, UMMP 40360. c. Apertural view of paratype, UMMP 40352.

6. Turbonitella trunculinoda Linsley, n. sp. eels
a,b. Side views of holotype, UMMP 40367. c. Side view of paratype,
UMMP 40368.

460

Figure

BULLETIN 244

EXPLANATION OF PLATE 39
All figures of latex casts

Figs. la,b, X 2; figs. 4a,e,g, X 8; all other figures X 4

1, Omphalocirrus Sp... 0.0... cesee reer estes ees eneee eer aatenat eee 372
a,b. Basal view and slightly oblique basal view of UMMP 40385, show-

2: Streptacis 2? Sp:

ing the spines around the periphery and the bundling of the growth
lines.

se: 438

Side view of UMMP 40544. Note fine costae ‘and ‘inclination cot sutures.

3. ._Palaeozygopleura joanni,Linsley; n. Sp.0 ...2.2.cccccecce- ec es nse stenunesteons 436

a.

Side view of paratype, UMMP 40480, showing extreme backward
obliquity of the costae of the ultimate whorl of this rotund individual.
b. Side view of paratype, UMMP 40475. The ultimate whorl has been
broken back for about one-half of a volution. c. Side view of para-
type, UMMP 40476, showing smoothness of the nucleus and the erect-
ness of the earliest costae. d. Side view of paratype, UMMP 40473. e.
Side view of paratype, UMMP 40481. Note the much finer costae on
the ultimate whorl. f. Side view of paratype, UMMP 40479. g. Aper-
tural view of holotype, UMMP 40478. h. Side view of paratype,
UMMP 40482. i. Side view of paratype, UMMP 40477. j,k. Apertural
view and side view of paratype, UMMP 40474, showing an extreme
condition of crowding of costae.

4. Palaeozygopleura sibleyense Linsley, n. sp. SOR ts eee OG

a.

Apertural view of paratype, UMMP 40471, showing wide pleural
angle of this immature specimen. b. Side view of paratype, UMMP
40347, showing wide spacing of costae and slight constriction just
below suture. c. Side view of paratype, UMMP 40470. d. Side view
of holotype, UMMP 30686.

BULL. AMER. PALEONT., VOL. 54 PLATE 389

INDEX

Note: The left hand bold face figures refer to the plates. The right hand
light figures refer to the pages.

A
abditinoda,
Hhlersina ..... 31,32 353, 355, :379-
381, 382
Abitibi River Fm. 349, 350
Acanthonema 411
Agniesella 394
akidota, Mur-
chisonia 32/353;..30), 420:
421
alinae, Palaeozy-
gopleura ..... 435, 436, 437
Amherstburg Del. .... 336, 337, 338,
346-348
Amherstburg, Ont... 336, 338, 346,
352, 363
Amphipora 339
Anderdon Ls. 233-362
anderdonense, Stic-
tostoma ... 339
anderdoniae, Mur-
chisonia 32 344, 353, 355,
358, 421-426,
431
Anematina ... 435
argulata, Crenu-
lazone 33, 34, 35 354, 356, 358,
430-433
Aparchites 339
Arastra .... 385, 387
Arizonelia | 385
Atrypa ...

aurora, Syringo-
stroma . Pye tee

aurorella, Syringo-
stroma

Barychilina nee
Bass Island Ser. ....
Bassler Rs -S: :...:
Biattens Rises. ns.
Bellerophon .......
bicarinatus, Pleuro-
trochus et
bilineata, Mur-
chisonia

biserialis, Tur-
bonitella
Boggild, O. B.
Bois Blanc Fm.
Bojozyga ..

338, 339, 341,
351

339, 350
339, 350

3338
336
422
335, 394
365, 371

409

420-422, 425,
426

418, 419

368

337, 347-349
437

Brunner, Mond
Canada, Ltd.

Buechelia
Buffalo, N.Y.

carinatus,
Helix
Mourlonia

Carmen, J. E.

Cataschisma

Sp.
centrifuga, Ser-
pulospira
Cerithioides
Chiton
Coelozone
collarus, Copi-
docatomus

Columbus Is. .
commensurata,
Tylozone

compticarinatus,
Tropidodiscus

concomitans,
Pagodea

conicum, Micro-
doma

Conocardium

Copidocatomus
corrugata,
?Tsonema

corrugatus,
Straparollus
Crenulazone

cultricarinatus,
Tropidodiscus

curvilineatus,
Bellerophon
Tropidodiscus

Cystiphylloides

461

338-340, 346,
350-359, 361-
364, 370, 381,
382, 384, 388,
391, 402, 405,
406, 432, 434
385, 389

347

378

379

337, 347, 348
353, 355, 404-
405

30 404

373
434
367
396

38 354, 356, 407-
409
347-349, 411

25, 26 353, 355, 388-

393

25 353, 355, 368-
370

406, 407

409

339, 341, 351,
361

334, 407-409

36 354, 256, 411-
413

411
334, 338, 430-
433

25 339, 353, 355,
366, 369-371

365
365-370
339, 362

INDEX

D
delphinuloides,

Euryzone 398

Helicites 398
deludisubzona,

Murchisonia ERB BH ODE MATE

428
depressum, Isonema 411
desiderata,

Murchisonia 426
Detroit, Mich. 336, 348
Detroit River Gr. 333-350
Diodontopteria 341, 351, 361
dionysii, Straparollus 373
Disphylum 339

diversiformis, Stra-
parollus (Serpulo-

spira) 35 339, 341, 344,
S51 304500;
358, 359, 373-
376
Donaldiella ... 33 354, 356, 384
Donaldina ee 434
Donax 367
Dundee Ls. . 334-338, 341,
344, 346-350,
403, 404
=

Hetomavlalssee. ae. 423
Ehlersi= Gig Miew a. PaO OeOOlzOoOs
340-350, 380

ehlersi, Diodon-
topteria . 341, 351, 361
Hhlersinay =...) 333, 334, 338,
30300070095
380, 383
2-Sp: 30 383
eliana, Luciella 387
Emmonsia 339
Erie Co., Ohio 347, 348
Euconospira bs 380
Euomphalus .. 354, 356, 376-
378, 403
sp. A 236 376
sp. B 730 376
SpaaCae 36 Silt
Euryzone Boise Spe yy
355, 362, 397-
404
?sp. A 30, 31 402
SDs eee 3 403

Eversole Chart
Zone 411

extenuata,

Ectomaria 423
Murchisonia 422, 423

Solenospira 32 421-423

F

Fagerstrom, J. A.
faleatinoda,

349

Pagodea 38 354, 356, 406-
408

fasciata, Coelozone 29 353, 356, 397
Favosites Lo89, O41 oD
Fenner, Mrs. H. R. 335
filosa, GoniOspira . 384
Flat Rock Dol. 336, 338

fragosus, Scalae-

trochus 37 354, 356, 413-
414
France Stone Com-
pany Quarry 342-346, 351-
361, 363
Fritz, M. A. 350
G
Galloway, J. J. 350
Germany 351
goldfussi, Ompha-
locirrus 372
Goniospira 384
Grabau; A. We -.:. 335-337, 409-
411-, 422-423

gracilicrista, Mur-
chisonia nied ODasaD Daa
425
granulata, No-

donema 28 341, 344, 353,
355D3:398,.309:
394-396, 413
H
hamiltoniae,
Loxonema 436, 437
Palaeozygopleura 436, 437
Helicites 398
Helix 378
Heterophrentis ............ 339
Homotoma 424
Hormotoma 433
Hormotomina . 349, 428-431
1
imbricata, Mur-
chisonia ... x 411
incomptum, Ceri-
thioides |... ....33 354, 356, 434,
435
Ingersoll, Ont. 347
Tsochtlinia yee 339
Isonema 349, 411-413
J
James Bay, Canada .. 349, 350

462

INDEX

janus,

Mesocoelia 433

Murchisonia ............ 433
Jedriayesse.. ... 416
joanni, Palaeozygo-

JOIKETUURETA sas ceganseconiee 39 344, 354, 356,

436, 437
K
Kesling- RR. V: .... 334, 338, 340,
342-348
Kloedeniiay. ......... 338, 339
KMcht eI Be pe... . 335, 364, 384,
394, 395, 410,
411
Kwataboahegan
RIVET ee 350
E
lacunata,
Zalozone . 26, 27, 28 353, 355, 384-
388
jeanew A. Ca 336
latitornata,

Euryzone ..... 29, 30 353, 355, 358,

399-401
Leiorhynchus ...... pt 338
JGOROWaeINE Yin. heat 347
lindstromi,

Sealaetrochus . ; 413, 414

MrOCchUSi 2-6 AU 413
lemisleys Aue... 335
Linsley, JoAnn . 335
linsleyi, Murchi-

sonia (Hormotomina) 430
OdOMATIa ere... 431
Oxonema se. : 436, 437
Loxoplocus 33 354, 356, 383,

384
GUCaS SD Olea 336-338, 340,
342, 343, 345-
351
Guciella: 2... 385, 387
M
maia, Murchisonia

(Hormotomina) 428-430
manitobensis, Ompha-

LOCIEEUShe ee 372
Martinson, N. W. ........ 349, 350
Mesocoeliam ==... 428, 433
IMC eliaMe ease ee 434
Michigan. 10 .f...2:..:.. 333, 334, 337
Microdomia™ 2. ..3....).... 409-411
minuta, Murchisonia 421
Monroe Himes... 21... 336, 337
Mourlonia Mi ODO NOOO soo

OSD ete sorte. 31 378

Murchisonia -.. 044, 351, 409,
419-430, 433,
434

Murchisonia
(Hormotomina) 430

N
Naticopsis 338, 414-418
Natress, T. H. 336
nattressi,

Amphipora 338, 339
Nodonema 334, 394-396
fe)

obstipisutura,
Mesocoelia 35 354, 356, 428,
433-434
OOM ee eee Bao, o00, Oa;
342, 347, 348
Omphalocirrus 351, 354, 356,
372
sp. - eee) 372
Onondaga Le. ............ 337, 346, 347
Ontario, Canada 333N33D-300;
348
opimavoluta,
Naticopsis .... 304, 356, 415-
417
Ottawa Co., Ohio 347, 348
P
Pagodea eee 460-408
Palaeozygopleura .. 341, 359, 435-
438
parallela,
Bojozyga ........ 437
Palaeozygopleura 437
Rankss We Aten. 350
paucinodosa,
Bhilersina™ ...:2...:: KWishpy op yetsy
383
pegmihumerosa,
Naticopsis _........ 38 354, 356, 414-
416, 419
penduliobesa, Murchi-
sonia (Hormoto-
mina) 33 353, 355, 429,
430
Pentamerella ...... 338
pentangulatus,
Euomphalus ... 376
petilitornata,
Euryzone ..... 28, 29 353, 355, 358,
359, 398-401
pharkidopyndax,
Euryzone e829 300(00D.4002

402

463

phillipsii,

INDEX

Naticopsis 414-417
planifrons,
Naticopsis 38 354, 356, 415-
418
Platyceras 354, 356, 405,
406
sp. 37 405
Pleurotomaria verna 397
Pleurotrochus 409
Portlockiella 394
Prosser, C..S: 336
Punctoprimitia 339
Raisin River Dol. 348
Raphistoma 385, 389
Rhineoderma 394, 395
Sandusky Co., Ohio 347, 348
Scalaetrochus 413
Sealites .... 389
serpula, Euomphalus 374
Serpularia Sue
Serpulospira 373-376
Shansiella 394
Sherzer, W. H. 335, 336
Sibley Quarry 341, 342, 351-
361, 363, 368,
370, 372, 411

sibleyense,
Conocardium

Palaeozygo-
pleura

sibleyensis,

Murchisonia ......

Silica Fm.
Silica, Ohio ,

Solenospira
extenuatum

Stauffer, C. R.

Stictostroma
anderdonense

Straparellay 2s.

Straparollus
Straparollus
(Euomphalus)

Straparollus
(Serpulospira)

339, 341, 351,
361

39 341, 354, 356,
358, 436, 437

32 341, 353, 355,
358, 359, 425-
427

aoe 346
342, 343, 346
348

421-423
337-339, 347

339

aes 412

.... 373-378, 126

354, 356, 376-
378, 403

.... 3389, 341, 344,
351, 373

Sterptacis 354, 356, 434,
438

SD: ee) 438
Stringocephalus Zone 351
Stumm, E. C. 334, 338, 340-

348, 371
stummi,

Bellerophon 25 358, 353, 359,

371
subcostata, Naticopsis 418
subovatus, Naticopsis 415
Sylvania Ss. 335-338, 345,

348
Syringostroma . 339, 350
Tapinotomaria | 394
telescopium,

Cerithioides 434, 435
Trachydoma 416
Trechmannia 380
trepomena,

Murchisonia 420
tricarinata

Homotoma 424

Hormotoma 424

Microdoma 36 344, 358, 354,

356, 423
tricarinatus,

Pleurotrochus 409, 423
tricincta,

Murchisonia 420
Trochus

(Scalaetrochus) 413
Tropidodiscus 358, 365-371
tropidophora,

Loxoplocus 354, 356, 383,

384

Murchisonia ............ 383
{runculinoda,

Turbonitella .......38 354, 356, 418,

419
turbinatus,

Murchisonia + 419
Turbonitella 416, 418, 419
turricula, Tylozone 26 353, 355, 392,

393

Tylozone ee BLE Shite GD)

355, 388-393

typa, Cataschisma ..... 404

Van der Schalie, H. 335

vasulites, Bellerophon Sel

ventricosa, Naticopsis 415
verna,

Coelozone . 397

464

INDEX

Pleurotomaria ........ 397
vesculilineatus,

Tropidodiscus 25 344, 353. 355,

365-370
vesna, Palaeozygo-

PIEUPA were es es 436
vetusta, Platyceras .... 405
vittatus, Donax .......... 367

WwW
Wiaines: Rashes 2... 350
Wien Ze Wis Sk sac aie 384

465

Whitfieldi,

Streptacis . 438
Wienert, H. 335
Williams, M. Y. Sul
Wilson, A. E. . 349

Mi
Yochelson, E. L. 335, 364
Z
Zalozone obs OOORODOs
355, 384-388

—
7
:
:
o
;

XLVII.

XLVIII.

XLIX.

Volume I.

II.

ITI.

IV.

VI.

Carte eG. DD Ted pla ccste ses cnssacesetvcccehontadssaocevicossavis acdeecesevezes 16.00
Type and Figured Specimens P.R.I.
GENO Sey Ek 9) a) SSA BP s9 9 35 DN a ices sos oka cochek csevesecerooeectasadeeoscucetovees 16.00

Australian Carpoid Echinoderms, Yap forams, Shell Bluff,
Ga. forams. Newcomb mollusks, Wisconsin mollusk faunas,
Camerina, Va. forams, Corry Sandstone.

CN EDS) 675g DD AS Dla tccs sae cei hed Sesostetteacn ton ctisaes ntbassioesecaesbichs 16.00
Venezuelan Cenozoic gastropods.
IN Geel 4-198 )5:4 27 ppie 39) Plas | (cin.0icieccacsesctessectscsnccetecssscascuasseotwos 16.00

Ordovician stromatoporoids, Indo-Pacific camerinids, Missis-
sippian forams, Cuban rudists.

CINGS199=203)FeS'65c pps Sap Sayer cercrc cece recat eoeeesc tetera 16.00

Puerto Rican, Antarctic, New Zealand forams, Lepidocyclina,
Eumalacostraca.

NGS 204) S64 ep p's. 1G3i up lsissessccsceesetecroes oroeeue asd iesovasadeveesvdeaneeteete 16.00
Venezuela Cenozoic pelecypods
(INoss9205=21E) a9 ppt, 20) piss ists csossceccct ccscesesoeescusststactosteceeeenet 16.00

Large Foraminifera, Texas Cretaceous crustacean, Antarctic
Devonian terebratuloid, Osgood and Paleocene Foramini-
fera, Recent molluscan types.
(NOs e212 2217 ee SAS pp 83) PSs yas cucscées esoussheosscodcccocssessarsonteeeeeess 16.00
Eocene and Devonian Foraminifera, Venezuelan fossil
scaphopods and polychaetes, Alaskan Jurassic ammonites,
Neogene mollusks.
(Nose AUS) SelOS Bin pisgiS spl Sen cccsccsccec=cvst.cdesstocccescestesseseceitvascasienssoctes 18.00
Catalogue of the Paleocene and Eocene Mollusca of the
Southern and Eastern United States.
CN ose2 19-224) E67 lip p83 oi DI Seuiecsceceseseccatsecstsnotessoccossetsseetiatcasseves 16.00
Peneroplid and Australian forams, North American carpoids,
South Dakota palynology, Venezuelan Miocene mollusks,
Voluta.
UINOS522252230) 2 SUS r pp 42 iPS, dencac-csserccencctecvcescuccecsceecectecssszeres 16.00
Venezuela and Florida cirripeds, Antarctic forams, Linnaean
Olives, Camerina, Ordovician conodonts, Niagaran forams.

(los eal=2a2)e AZO pp, LO. Plas, cosscsccececsncnccsvacwcss nstesccessscicvesseosazen 16.00
Antarctic bivalves, Bivalvia catalogue.
AUIMGS 255-250 aS 87 PDs 0 AS. DISs¢ i c.cseadconescescetipcsnedecssavascsesateosesers 16.00

New Zealand forams, Stromatoporoidea, Indo-Pacific, Mio-
cene--Pliocene California forams.

(Nos2p237=238) se 488 pps 45a DIS.) cesececscsseracsrateccassaiee cacevasscevccoareotes 16.00
Venezuelan Bryozoa, Kinderhookian Brachiopods
INO S56239°243))ee SAVE Ppa 24s DISs tere sscvstesczsctcstersveststessvecvarstsesctcostees 11.25

Dominican ostracodes, Texan pelecypods, Wisconsin mol-
lusks, Siphocypraea, Lepidocyclina.

PALAEONTOGRAPHICA AMERICANA

See Johnson Reprint Corporation, 111 Fifth Ave., New York,

N.Y. Monographs of Arcas, Lutetia, rudistids and venerids.

MINgg G02) 50551 pps, 37. PSs s.cccececcuscnsenescasveatonacoacoascdosbectoresscds 23.00

Heliophyllum halli, Tertiary turrids, Neocene Spondyli, Pale-
ozic cephalopods, Tertiary Fasciolarias and Paleozoic and
Recent Hexactinellida.

(ING d<25) o/ eS LSD Ps hOl DIG.) se ssccusecsstccscovasctuessintosaptcncesseasspns sabe 28.00

Paleozoic cephalopod structure and phylogeny, Paleozoic
siphonophores, Busycon, Devonian fish studies, gastropod
studies, Carboniferous crinoids, Cretaceous jellyfish, Platy-
strophia, and Venericardia.

MONG 2 2OSSB Ne AG 2 Pp TOM lay suse cussaccace cowacdicneceatinrslinie uaacasens 28.00

Rudist studies, Busycon, Dalmanellidae, Byssonychia, De-
vonian lycopods, Ordovician eurypterids, Pliocene mol-
lusks.

(Nos 3134-311) 2 mee 4-457 DD Olonp lar ucascuccssccvecevesevsesussceravascnsessssetbose 32.00

Tertiary Arcacea, Mississippian pelecypods, Ambonychiidae,
Cretaceous Gulf Coastal forams.

CINOS7 7588259) 5 e055 Pps, R29) pl Sacges cree tet oee ce een rec see esa cneee duct 8.75

Lycopsids and sphenopsids of Freeport Coal, Venericardia.

Vols.

XXIV.

XXV.
XXVI.

XXVII.
XXVIII.

XXIX.

XXX.

XXXII.

XXXII.

XXXIITI.

XXXIV.

XXXV.

XXXVI.

XXXVII.

XXXVIII.

XXXIX.

BULLETINS OF AMERICAN PALEONTOLOGY

I-XXIII. See Kraus Reprint Corp., 16 East 46th St., New York,
N.Y. 10017, U.S.A.
(Nos. 80:87).7 .) 334 DDs, 27 (plsiy occstecactactccceetaeeeceteeceeeeeessereneeeee 12.00
Mainly Paleozoic faunas and Tertiary Mollusca.
(INO8:788-94B)) S/S 06 pps SOND Sse nwcesse-seesescorssesccosecusesrassetocsssseeteetee 12.00
Paleozoic fossils of Ontario, Oklahoma and Colombia, Meso-
zoic echinoids, California Pleistocene and Maryland Mio-
cene mollusks.
(Nos595=100) 5 v4 20 pp cS 8iiplss cree csrese corcsreereeesceccsteeseoctoeestreeee 14.00
Florida Recent marine shells, Texas Cretaceous fossils, Cuban
and Peruvian Cretaceous, Peruvian Eogene corals, and
geology and paleontology of Ecuador.
(INos:#1O1=108) 1376 (pps SOmplste eee e ee eeee ce eee 14.00
Tertiary Mollusca, Paleozoic cephalopods, Devonian fish and
Paleozoic geology and fossils of Venezuela.
(Nos: 1092114) 5-412) ppt) S4iplaiieccinssectcscscccctstesteasscecoscsesestecostones 14.00
Paleozoic cephalopods, Devonian of Idaho, Cretaceous and
Eocene mollusks, Cuban and Venezuelan forams.
(Nos-115-116) 5; (738i ppiwoZuplasi ct ecccc eee etree ere ceeer ne 18.00
Bowden forams and Ordovician cephalopods.
(NOD) E9563" PpnOSmplatetcc cr vccce sree cece ctccrescreescere oes 16.00
Jackson Eocene mollusks.
(Nos 1'18-128) 458 ippie 7p Secccsscee cose coere eects 16.00
Venezuelan and California mollusks, Chemung and Pennsyl-
vanian crinoids, Cypraeidae, Cretaceous, Miocene and Re-
cent corals, Cuban and Floridian forams, and Cuban fossil
localities.
(Nos.\.129-133) 5: 294) ppice39 e plain cescsccccccsoocscscnvcdseneessnosteteteseess 16.00
Silurian cephalopods, crinoid studies, Tertiary forams, and
Mytilarca.
(INos.)'134-139))s: 1448 spp) (Si plas: ciccccosds cattvetcscosctiscess sere eecee 16.00
Devonian annelids, Tertiary mollusks, Ecuadoran strati-
graphy paleontology.
(Nos. 140-145); 2400 (pp.. 19% pls. .ccc..cc.ctscccscccesascsesctsecsessateoneres 16.00
Trinidad Globigerinidae, Ordovician Enopleura, Tasmanian
Ordovician cephalopods and Tennessee Ordovician ostra-
cods and conularid bibliography.
(Nos; 146-154)... 386" pp:,:31 iplsy oo. ccsesseete te cere cece 16.00
G. D. Harris memorial, camerinid and Georgia Paleocene
Foraminifera, South America Paleozoics, Australian Ordo-
vician cephalopods, California Pleistocene Eulimidae, Vol-
utidae, and Devonian ostracods from Iowa.
(Nosi3155-160) 04:12" ppsw53 tiple: ke ease ccesstencsee coast ee eee 16.00
Globotruncana in Colombia, Eocene fish, Canadian Chazyan
Antillean Cretaceous rudists, Canal Zone Foraminifera,
fossils, foraminiferal studies.
(Nos.} 161-164). 486° pp.. 37 poles) sie tee 16.00
Antillean Cretaceous Rudists, Canal Zone Foraminifera,
Stromatoporoidea.
(Noa; ;'165-176) 3.447 pp., 53: pla. seccscecicascsceicascsrecetatornsarnee eee ee 16.00
Venezuela geology, Oligocene Lepidocyclina, Miocene ostra-
cods, and Mississippian of Kentucky, turritellid from Vene-
zuela, larger forams, new mollusks, geology of Carriacou,
Pennsylvania plants.
(Nos; 177-183) <:448) pp, 36 ples, sscectecet orice fcoeacas tne eee 16.00

Panama Caribbean mollusks, Venezuelan Tertiary formations
and forams, Trinidad Cretaceous forams, American-Eur-
opean species, Puerto Rico forams.

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