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oe THE PHYLOGENY OF CERTAIN CERITHIDA in

Ons. FROM THE GEOLOGICAL ‘DEPARTMENT
ee EOF COLUMBIA. UNIVERSITY :
7 ae _ VOL. XXI. No.1

: : BY = am
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CONTRIBUTIONS FROM THE GEOLOGICAL DEPARTMENT
OF COLUMBIA UNIVERSITY
VOU XA. NOwst

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‘

THE PHYLOGENY OF CERTAIN CERITHIIDE

BY

ELVIRA WOOD, A. M.

Submitted in partial fulfillment of the requirements for the degree of Doctor of
Philosophy in the Faculty of Pure Science, Columbia University

[Reprinted from the ANNats of the New York Academy of Sciences, Vol. xX,
No. 1, Part I, pp. 1-92, Pll. I-IX. Published 14 May, 1910]

[ANNALS N. Y. ACADEMY OF SCIENCES, VoL. XX, No. 1, Part I, pp. 1-92,
Pll. I-IX. 14 May, 1910]

THE PHYLOGENY OF CERTAIN CERITHIIDA
By Etvira Woop

(Presented in abstract before the Academy, February 7, 1910)

CONTENTS

Page
SRPMPESU NEG LCVCA TLCS UL CHINE Sec Pees oy coher olay eset che fates senate fot als cavare/lcy oFie-e erici os “ao eveu avatars: civics ist ntarcia 2
Gamal Tories) hos Go aoocauoototoco une codon cH dusomccet om. 2
ANC OT ES CaTVeTIGN eee aoa ceee pe csn > pooeoanoamonnouet ooo panor: 6
Il. Selection of a genotype for Cerithiwm sensu stricto....... SEMA diner 6
Mile GCmUSMO CIE RIINi= COMME. © racic. oalervere' cies wlee eo es sieve se ee eis wie vivilell 10
V. Ontogenetic description of species........... 2. eee eee eee eee tenes 14
PAMPIREC CII SPECIES ay sects) eye toler euc’ Suese les eels ele, =) alsey/ay ora leve/el susie ele (Slate oaks 14
A GCILERUUT Ue VULOCTOSUNY LLOUP siete ieicie alei~ oleate «i <1es0/e) ool ee 14
(ADOC KNAXSIES Ges tenohmnc Soon ccatonocbamcad- 14
GaeAIMERI GATES ECIOSI cerece cparena<l-e cisbereneretiatere gaia) aete 30

2. Genera and species related to the Cerithiwmn pueerosie
ARNON eo oes anoedu Oba gonn Doc obo orcccp ac coehante.s <- 33
LCT OCC RAHUL DES CO GIOETOD COTO COORDS DOOMIOD.C 6. 33
B. Pleistocenie species of Vulgocerithiwm. .........6.ccecceesace 39
MOM AGENIEG PSMPEClESs Of \OOHUGUUMNU 05 tolelel «) <iois Sil =)eho) ole sa ae -ladalorateens 39
Tt) SAVIO COMIC SPECIES etecie 4 it cis} 16 = cil aclete tela) issue ste iat ote) efcNelralalal op epeteieha 43
Tie OEFAUINCUIIDS. (6 on Re OCOD EIA SCRE DIO ODOO ae 15h aeieers 43
DY AVAGO ECAC TLOL SEC e PRECIOnORICIE HOODIA IS cia cicicvcidr a ben cicrs <1 46
By Olizocemic’ and WOCeMIE SPECIES < 2.5. = aes e1e1« scien w «wl eleatal 47
102 COLEGIO AL AIO entice CED ORG RCO OOO dons Gn ndecn 47
PP AVAGILOGETULIUVUNIU. Gm aid aye'e.e\e'a, diss 0/9 ails eats oisasve mi che) dapanarateintaee 57
MEM PAOLLIIUILE Sok oie a oe vis ey ss hela oa 0: &: rane sien oles alee pete eer Ree 59
AM E OEUITUULOD SIS: Pack shales Oss 5 siz,4. ale! cia ielalat=fajeerageyeraioeterteiees 65
FMM ULC OCCTLENANENTE | stefocs.te clahevs d/scc) 0) ss [oid 8.4) slencd tele otal tapers 77
MeL @retacie: SPECIES! Of. COnUEntins .:5< salen =. @ 0 0lselnicle) sie ste letsislateraiaie 79
Geurassicaspecies Of Ceritniuinie as. << 00 ocleelaniciseinia este sieeyeaine 80
Wi, Shininiiigy “ge diewd bis.o Dats CREOIE eI To eIC Or cinIeromo Ucoecoric i ncene brit Ar 81
Wise hvlozenetic. table of certain Cerithiide. .. 0.0.00. 66a e vcs ce vewses 85

Not. The author alone is responsible for the terminology used throughout this
article. EDITOR.

ANNALS NEW YORK ACADEMY OF SCIENCES

wo

Il. INTRODUCTION

The literature of the genus Cerithium is already extensive, including
papers which treat the subject from both the paleontological and the
zoological point of view. The genus is treated to a greater or less extent
in all general works on conchology, but such treatment is confined to
descriptions of the genus and of the different species referred to it,
without any attempt to trace phylogenetic relationships, and the same is
true, with few exceptions, of paleontological papers on the subject.

Recently M. Cossmann [1906] has published a monograph on the
Cerithiide, in which he takes account of the relationship between differ-
ent forms and presents an elaborate classification of the various genera
and sub-genera included within the family.

M. Cossmann’s conclusions are largely based on characters appearing
late in the life history of the individual, and he lays especial stress upon
the various features of the aperture. The present paper, being founded
upon a different method of work, as explained below, necessarily reaches
conclusions somewhat different from those of M. Cossmann.

A complete bibliography of the works consulted in the preparation of
this paper is given on pages 86 to 91.

The principles of phylogenetic development discovered and formulated
by Hackel, Hyatt, Cope and others have been successfully applied in
studies of the phylogeny of several groups of greater or less extent, such
as Hyatt’s studies on the Cephalopoda, Jackson’s on the Echinodermata
and Grabau’s on the Fusidae. The present paper is an attempt to apply
these principles in working out the relationships of such species of
Cerithium as could be obtained.

The fundamental law upon which all the work is based is the law of
morphogenesis, which has been stated by Hyatt! as follows:

A natural classification may be made by means of a system of analysis in
which the individual is the unit of comparison, because its life in all its
phases, morphological and physiological, healthy or pathological, embryo,
larva, adolescent, adult and old (ontogeny), correlates with the morphological
and physiological history of the group to which it belongs (phylogeny).

According to this principle, a study of the life history of individuals
furnishes a ready and most reliable means of tracing the development of
the group to which they belong. Hence, in the present investigation,
the starting point has been the study of individual development and a
comparison of the records thus obtained. Similarity in the character

1A, HyaTT; ‘Genesis of the Arietide,”’ p. viii. 1889,

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 2}

and order of introduction of the various features of the shell are indica-
tions of relationship, and the comparison of a sufficient number of life
histories will furnish a phylogenetic tree whose completeness depends
upon the abundance and perfection of the material available for study.
In making such comparisons, it is important to take account of paral-
lelism in development, in consequence of which similar characteristics
may appear for a greater or less portion of the life history in individuals
belonging to divergent groups. An illustration of this is to be found in
Vieinocerithium bouei Desu. and V. parallelum sp. nov. of the Hocenic
of the Paris basin. hese shells are closely similar in the adult and have
been referred to the same species, but they differ in developmental his-
tory. Both have, in the adult, one extremely prominent spiral around
the middle of the whorl, with strong ribs crossing it and a less prominent
spiral below. The remainder of the surface is covered with spirals of
secondary, tertiary, and higher orders. In the young, Vicinocerithiwm
bowet has three spirals, the lowest of which is the most prominent (plate
vil, fig. 6). Later, in the growth of the shell, finer spirals are inter-
ealated, and all are crossed by ribs. At a still later stage, the upper
spiral of the three primary ones becomes the most prominent and finally
develops into the strong carina of the adult (plate vin, fig. 6, and plate
1x, figs. 5, 6). Vicinocerithium parallelum also begins with three spirals,
of which the lowest one is the most prominent, but ribs are present as
soon as the third spiral appears (plate vit, figs. 4,5). Later, the median
spiral becomes as prominent as the lower, and for several volutions the
two are equally prominent, while the upper spiral diminishes in propor-
tion, and additional fine spirals are introduced on the shoulder thus
formed (plate vit, figs. 4, 5). The median spiral continues to increase
until it forms the carina of the adult (plate rx, figs. 3, 4), a feature
which was formed in the preceding species by increase in the upper spiral
of the three primary ones. These shells are parallel in the adult, but
differ in development and are to be traced to different ancestors.

The phylogenetic record is obscured by the fact that not all of the
history of a group is expressed in the ontogeny of a single species. As
new characters are introduced in the evolution of the group the record
becomes too long to be repeated during the lifetime of a single individ-
ual, and each of the ancestral stages occupies a shorter and shorter por-
tion of the length of the shell, until some stages disappear altogether.
An individual thus shows the adult characteristics of its ancestors at-an
early period of its life history. These facts are expressed as follows in
Hyatt’s law of acceleration :*

2A, Hyatt: “Genesis of the Arietide,” p. ix. 1889,

4 ANNALS NEW YORK ACADEMY OF SCIENCES

All modifications and variations in progressive series tend to appear first in
the adolescent or adult stages of growth, and then to be inherited in successive
descendants at earlier and earlier stages according to the law of acceleration,
until they either become embryonic, or are crowded out of the organization,
and replaced in the development by characteristics of later origin.

This law is well illustrated in the development of two Paris Basin
shells, Potamidopsis tricarinata LAMARCK of the Calcaire Grossier and
Potamidopsis roissyi DESH. of the Sables Moyens. In the young, the
surface ornamentation of the latter species consists of two rows of nodes,
the lower being the more prominent. The same is true of the young P.
tricarinata, but this stage lasts much longer in the latter than in the
former species. The stage with two rows of nodes is followed by one in
which there is an additional row of fine nodes intercalated between the
two, and the lowest row is still the most prominent. At about the ninth
volution of P. roissyi this ornamentation is fully developed, and it repre-
sents the adult ornamentation of P. tricarinata, which is found at a lower
geological horizon. The adult characteristics of P. tricarinata last for
hardly more than one volution on P. roissyi, which soon develops its own
characteristic adult ornamentation of three rows of nodes, the uppermost
of which are largest and transversely elongated. (See Deshayes, 1824,
plate L, fig. 13.) P. tricarinata is the ancestor from which P. roissyi
developed, and the latter records this fact in its ontogeny.

Two individuals belonging to the same phyletic series and living dur-
ing the same time period frequently do not reach the same degree of
complexity in structure. One may retain its primitive characteristics
until late in its life history, only diverging from the ancestral type on
becoming fully adult, while another may pass through its ancestral stages
early in life and show a long succession of characteristics of later origin.
The former is retarded in its development in comparison with the latter.
Cerithvum tuberosum is an illustration of a retarded shell, retaining, as
it does, the two equally strong spirals until the tenth volution, the whorls
only acquiring their acute angled outline on the twelfth volution. Ce-
rithium adansoni passes through the same ancestral stages as C. tuber-
osum, but loses the obtuse angled outline of the whorls at about the sixth
volution and after that acquires nodes, blunt spines and numerous addi-
tional spirals. It is a highly accelerated recent shell.

Acceleration and retardation are expressed not only in the ontogeny
of the individual as a whole, but each character may be independently
accelerated or retarded. Cerithium graciliforme (Tryon, 1887, plate
xxi, fig. 77) retains the obtuse angled outline of the whorls to the
ninth volution, while C. echinatum (Kobelt, 1898, plate xx, fig. 6) loses

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 5

this type of outline at about the seventh volution. C. graciliforme is
therefore a more retarded shell than C. echinatum in this respect. In
the acquisition of nodes, however, it is accelerated, for it acquires nodes
on the ninth volution, while C. echinatum does not develop them until
the thirteenth volution. This differential acceleration and retardation
often produces a wide difference in the appearance of adult shells, with-
out the introduction of any new character.

Individuals having the same development for a greater or less portion
of their life history, but differing in the adolescent or adult stages, may
be regarded as divergent descendants from the same ancestral stock. A
striking illustration of such divergence is found among recent species of
Cerithium in the group of which C. tuberosum may be taken as a type.

In addition to the types of variation already noted, there is a kind of
individual variation which seems to differ from all, and that is in the
slight accentuation of the characters of the shell from their earliest ap-
pearance to the last volution. This is seen in individuals of Cerithium
lamellosum, some of which show secondary spirals distinctly on all the
whorls, while on others these spirals are but faintly indicated. This may
be due to some condition in the environment, possibly to more lime in
the water or to better food supply in the case of the well-marked indi-
viduals, or it may be due only to an inherent tendency to variation.

Acceleration and retardation and the introduction of new characters
may cause divergence sufficient to serve as a basis for the separation of
species, or they may appear to a less degree in individuals referred to the
same species. Where many individuals are present, we find gradations
in the various characters compelling us to establish varieties, and the
more extensive the material the more insensible the gradations become,
so that 1f our collections were sufficiently extensive, it would doubtless be
possible to establish a perfect gradational series among various species of
Cerithium, as in the classic example of the Planorbis of Steinheim.*

As might be expected, the greatest difficulty encountered in determin-
ing the phylogeny of Cerithiwm has been due to the scarcity of material.
It has been impossible to secure specimens of shells from the early Meso-
zoic horizons which might be expected to furnish the ancestors of the
forms occurring in such abundance in the Eocenic. A similar difficulty
arises in connection with late Tertiary and early Quaternary material in
which we should expect to find the connecting links between Eocenic and
recent species. In the absence of specimens of shells, figures and de-
scriptions have been freely used, but the figures of the early portions of

2A. Hyatt: Mem. Boston Soe. Nat. Hist. 1880.

6 ANNALS NEW YORK ACADEMY OF SCIENCES

the shell are unreliable, and in all the older works they were considered
too unimportant even to be mentioned in the descriptions. In most later
works, also, insufficient attention has been given to the character of the
protoconch and early conch stages of the shell. For this reason all sug-
gestions concerning phylogeny which are based on figures and descrip-
tions alone are to be considered as merely theoretical and as subject to
revision, if actual specimens become available.

Acknowledgments and thanks are extended with pleasure to those who
have rendered assistance during the preparation of this paper; to Dr.
Carlotta J. Maury for the loan of Oligocenic shells from the Paris Basin,
and to Dr. Amadeus W. Grabau for many helpful suggestions The writer
desires especially to express her appreciation of the very liberal manner
in which Mr. Samuel Henshaw, Director of the Museum of Comparative
Zoology, has placed at her disposal the resources of the collection in his
care. The following officers of the American Museum of Natural His-
tory have also been most generous in providing opportunities for the
study of the material in that museum: Dr. Hermon C. Bumpus, Director,
and Prof. R. P. Whitfield and Dr. E. O. Hovey, Curators of the Depart-
ment of Geology and Invertebrate Paleontology. Valuable assistance in
collecting the literature of the subject has also been given by the libra-
rians of both the above mentioned institutions.

II. SELECTION OF A GENOTYPE FOR CERITHIUM SENSU STRICTO

The selection of a type of the genus Cerithium has given rise to much
difference of opinion, and the determination of the proper species to be
used as a standard of comparison for other species of the genus has led
to a revision of the literature on the subject.

The name Cerithiwm was first used by Fabii Columne [1616] in his
treatise, “De aquatilibus aliisque nonnulis animalibus.” He figures a
shell under the name of Buccinum tuberosum, which in his description
he says should be referred to “Cerithia.” On the margin of the page op-
posite this reference are the two names Buccinum tuberosum and Ceri-
thium parvum. No description or figure accompanies the latter name, and
it is possible that Columnz intended to substitute this name for that of
Buccinum tuberosum, for the shell figured on page 53 of his work; but
since this is not definitely stated, the specific name tuberosum is retained
for the shell figured and referred to Cerithiwm. Columne gives no de-
scription of the genus Cerithiwm, and his description of the species tuber-
osum is meager, but his figure of the latter is sufficiently good clearly to
identify his shell with the one described by Lamarck [1843, p. 292]

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA v

under the name of Cerithium erythrwonense and by Sowerby [1855]
and Reeve [1866] as Certthiwm tuberosum.

Adanson [1757] described and figured a shell from Senegal which he
believed to be identical with that of Columne. His figure closely re-
sembles Cerithium tuberosum, except in the aperture, which is more like
that of the shell from Senegal described by Bruguiére as Cerithiwm adan-
sont. Adanson was describing a shell collected by himself at Senegal,
and his description seems to indicate quite definitely that his shell is
really C. adansoni BRUGUIERE, since it mentions the strongly spinose
tubercles not found on C. tuberosum and gives the size as two inches, or
about 50 mm. ‘The youngest specimen of C’. tuberosum seen in the col-
lections studied was 57 mm. long, and full-grown individuals are 64 mm.
or more in length. ‘The similarity in the figures may perhaps be ac-
counted for by a tendency on the part of the artist to imitate a figure
already published and believed to be of the same species. Adanson named
his shell simply “‘Le Cerite,” and this name would not stand, since it does
not conform to the binomial nomenclature.

The first published description of the genus Cerithium is by Bruguiére
[1792]. He divides the genus into three groups, the first of which corre-
sponds to Vertagus KLEIN and the second to Cerithium sensu stricto.
The first species of this second group is Cerithiwm nodulosum, which the
author believed to be of the same species as C. tuberosum CoLUMNA:,
since he cites the latter species in his synonymy. ‘The description, how-
ever, corresponds with C. nodulosum, as the name is now applied. The
second species of this group is C. adansont, the description of which cor-
responds closely with that of “Le Cerite” by Adanson, and Bruguiére
states definitely that he is describing a shell of the same species as Adan-
son’s shell.

At a still earlier date Martyn [1784] figured under the generic name
of Clava four species which Dall [1907, p. 366] now refers to Cerithium,
as follows:

1. Clava rugata Martyn = Murex asper LINNE.

2. Clava herculea Martyn = Cerithiwm ebeninum BRUGUIERE.
3. Clava maculata Martyn = Cerithiwm clava BRUGUIERE.

4. Clava rubus Martyn = Cerithiuwm echinatum LAMARCK.

On the strength of these figures, Dall [ibid., p. 368] claims for Martyn
the first recognition of the genus Certthiwm, but Martyn published no
descriptions either generic or specific, and it hardly seems that these fig-
ures alone furnish a valid reason for changing the name of the genus
from Cerithium to Clava Martyn. Clava has long been established as

8 ANNALS NEW YORK ACADEMY OF SCIENCES

the name of a genus of hydroids, and the confusion that would arise in
the literature furnishes another reason for avoiding such a change.

In the first published description of the genus Cerithium by Bruguiére
no genotype was designated, and the first to make a definite selection was
Lamarck [1799]. He chose Murex aluco Linn&, which was described
by Bruguiére with the name of Cerite chenille. This shell belongs to
the first of the three groups described by Bruguiére, and it might well
remain the type of that group to which the name Pseudovertagus has
since been applied. It does not belong in the same group with the shell
to which Columne gave the name of Cerithiwm, as will be seen by com-
paring the life histories of the two species as given on plate 111, figs. 2,
3, 4; plate Iv, figs. 2, 3; plate v, figs. 1, 2; plate 111, fig. 6; plate Iv, figs.
6, 7; plate v, figs. 5, 6, and plate v1, figs. 4, 5. Lamarck himself seems
to have been dissatisfied with his own choice of a genotype, for two years
later [1801, p. 85] he redescribed the genus and mentioned Cerithium
nodulosum as an example of it.

Later authors have adjusted the claims of their predecessors in various
ways. Most credit the genus to Bruguiére, but others refer it to La-
marck or Adanson. A few of these may be mentioned: thus Montfort
[1810] credits the genus to Lamarck, choosing the genotype selected by
him in 1799. Link [1807] and Schumacher [1817] solve the difficulty
by dividing the genus into two groups, the former following Lamarck, in
1799, for his first group, and Bruguiére, with Cerithium adansoni as an
example of his second group, to which he gives the name Aluco. Schu-
macher retains the name Certthiwm for both his groups, crediting them
to Lamarck, with C. aluco as genotype for one and C. nodulosum for the
other. Among the authors who refer the genus to Adanson are Deshayes
[1824], d@Orbigny [1842-1843], Sowerby [1855], Fischer [1887] and
Tryon [1887]. Bruguiere, being the first to describe the genus as such,
is still more widely recognized, and a few of the authors who have fol-
lowed him are Swainson [1840], Reeve [1866], Cossmann [1906] and
Dall [1907].

In the choice of a genotype equal diversity is shown, for Fischer, while
he refers the genus to Adanson, chooses C. nodulosum as the genotype.
Deshayes is consistent in choosing for the type of the genus C. adansoni.
Of those who refer the genus to Bruguiére, Swainson and Cossmann
choose C. nodulosum, and Dall and Dautzenberg and Dollfus [1882-

1885] choose Murex aluco LINN® as the type of the genus.
Summarizing the facts already given, it appears that Columnez was

4The author has been unable to see this work, and is indebted to Dall [1907, p. 364]
for the reference.

————

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 9

the first to propose the name Certthium, which he did in connection with
a description and an easily determinable figure of a well-known species.
He gave it a name which conforms to the Linnean system of nomencla-
ture, and it appears to the writer that these facts are sufficient ground _
for referring the genus to Columne. Apparently the only reason for
discrediting his work and referring the genus to a later author is found
in the rule of the International Congress of Zodlogists, according to which
the date 1758 is taken as the starting point of the binomial nomenclature.
This rule is useful, but to enforce it indiscriminately would do great in-
justice to the pioneers in science whose work conforms with the standards
at present in use. This is especially true when, as in the present case,
there are additional reasons for recognizing the earlier work. In actual
practice the rule is not closely followed, since many genera described pre-
vious to the year 1758 are still retained under the name of the original
author. For example, among the Cephalopoda we have Belemnites Lis-
TER, 1678; Orthoceras BrryNn, 1732; Intuites Breyn, 1732, and among
Gastropoda Planorbis GuETTaRD, 1756, and Haliotis LinN&, 1735. Fur-
thermore, the reference of the genus to Columne would have the great
practical advantage of settling at once the vexed question of a genotype,
and this type is of such a character that it would, on the basis of phy-
logenetic studies, retain within the genus Cerithiwm a large number of
the species known by that name throughout the literature of the subject.

The work of Adanson, like that of Column, is pre-Linnean, and it
furthermore fails to conform to the binomial nomenclature.

If the rule of discrediting pre-Linnezan descriptions be rigidly adhered
to, the genus would be referred to Bruguiére, and the choice of Cerithiwm
nodulosum as genotype seems to come nearest to that author’s own con-
ception of the genus. The choice of Murex aluco for a genotype, as at
first suggested by Lamarck [1799], would result in substituting the name
Cerithium for Pseudovertagus and the use of a new name for the group
to which the former was originally applied. This would cause great
confusion in the literature and make the genus a different one from
what was intended by the early writers on the subject, since Bruguiére
was obviously trying to follow both Columne and Adanson in describing
first, C. nodulosum, which he believed to be identical with Columne’s
shell, and second, (. adansoni, which was “Le Cerite” of Adanson. He
merely fell into the common error of including under one name groups
of shells which he himself recognized to be different.

Cerithium nodulosum bears a superficial resemblance to C. tuberosum
and has been considered by some authors to be of the same species. It
is, however, quite distinct. According to the youngest specimens of

10 ANNALS NEW YORK ACADEMY OF SCIENCES

C. nodulosum at first obtainable, it seemed that the two species belonged
to the same phyletic series, but the absence of ribs on a somewhat younger
individual, received later, throws some doubt upon this supposed relation-
ship. The point can only be determined by a study of younger stages of
C’. nodulosum than are now available, and in case the latter shell proves
to be different in its development from C. tuberosum, it must represent
a very restricted group, for among species now referred to Cerithium
the absence of ribs on individuals having a well developed shoulder is an
extremely rare feature. In this case also, with C. nodulosum as geno-
type, the name Cerithiwm would be used in a very restricted sense, and a
new name would have to be given to the genus as understood by Column
and Bruguiére.

For the purposes of this paper, Cerithium tuberosum CoLUMN# will
be used as a standard of comparison for other species of the genus.

III. Genus CEerirHium Columnze

1616. Cerithiwn Fait CoLuMN2, De Aquatilibus, pp. 53, 57.

1784. Clava Martyn, The Universal Conchologist, London.

1792. Cerithium BRuGuUIERE, Hist. Nat. des Vers., Encye. Méth., I, pt. 2, 467.

1799. Cerithium LAMARCK, Prodrome nouy. Class., p. 73 (not seen).

1801. Cerithium LAMARCK, Syst. des animaux sans vert., p. 85.

1898. Cerithiwn Koper, Syst. Conch.-Cabinet von Martini u. Chemnitz, Bd. I,
Abth. 26, 2.

1906. Cerithium CossMANN, Hssais de Paléoconch. Comp., VII, 65.

Fic. 1.—Cerithium tuberosum. Copy of Columne’s original figure x 1.

After the description of Buccinum maximum and mention of other
species of Buccinum, Columne refers to this species as follows:

Sed rariorem hance parui Buccini tuberosi candidi, ad Cerithia referendam,
oris margine supra tubulum elata, et incumbens non inuersa ut in alijs magnis

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE sla |

effigiem omittere noluimus, quanimus huiusmodi alias differentias habeamus,
colore cinero orbitas depressioribus, magis densis minutisque tuberculis asperas.

While this description is meager, it is sufficient, with the aid of the
figure, for the identification of the species designated. The character-
ization of the shell as a small one excludes Cerithium nodulosum, with
which it has been confused. The reference to the margin of the mouth
as raised above the canal and resting upon it is like C. tuberosum and
unlike C. adansont. ‘The figure also resembles C. tuberosum in its high
spire, in the character of the aperture and of the ornamentation, so far as
this is indicated by the imperfect figure.

Description of Certthium by Bruguiére:

~

Genre de coquilles univalves, uniloculaire, 4 spire reguliére, qui a pour
caractére,

Une coquille turriculée, ouverture oblique, terminée 4 la base par un canal
étroit, totalement recourbé, ou moyennement recourbé, ou droit et trés-court,
mais jamais échancré.

Genotype selected by Lamarck, 1799, Murex aluco LinNf&; 1801,
Cerithium nodulosum BRUGUIERE.

The protoconch of the genus Cerithiwm has been observed in many
species and is found to be uniform in character. It forms a low, regu-
lar spiral of usually about one and one-half volutions. The limits of the
protoconch are not sharply defined, as the ornament begins faintly at
first and becomes gradually stronger, but for convenience the protoconch
has been assumed to end where the first traces of ornament appear. Prac-
tically the only difference found in the earliest whorls of the species
studied is in the extent of the smooth portion of the shell, which varies
from one and one-fourth to one and one-half volutions. This is due to
difference in degree of acceleration, the more accelerated forms having
the ornamentation crowded back to an early stage in shell growth.

The surface ornamentation of Cerithiwm consists of spirals, ribs and
nodes, the great diversity observable in the ornamentation of the different
species being due to the relative development which each of these feat-
ures attains. In forms sufficiently retarded to show the order of intro-
duction of the various features of the ornamentation, it appears to begin
as one spiral, or in accelerated forms as more than one, additional spirals
coming in above the first. Ribs next appear and nodes are formed by
the concentration of material where the ribs and spirals cross. In a few
cases ribs appear after the first and before the formation of a second
spiral, but in no case have ribs been observed before the appearance of at
least one spiral. Intercalated spirals may come in either before or after

12 ANNALS NEW YORK ACADEMY OF SCIENCES

the introduction of ribs, and they often become extremely numerous.
While the order of introduction of the types of surface ornamentation is
fairly constant, the precise volution at which a new feature will appear
is dependent on the degree of acceleration which the shell has attained
and often shows considerable variation within the same Linnean species.
In highly accelerated forms, both spirals and ribs may appear together
at the close of the protoconch stage. This is seen in Cerithium adan-
sont, plate 111, fig. 3.

The amount of embracing of the whorls in shells of this genus varies
within considerable limits, but as a rule the body volution is shorter than
the remainder of the spire.

The aperture is oval, with an oblique, more or less widely open an-
terior canal. Primitive forms have no posterior tooth, but in some
Kocenic and later forms a projection of the callus of the inner lip forms
a distinct tooth which defines a short canal between itself and the outer
lip.

In the earlier literature of the subject, the name Cerithiwm was applied
to all forms having in common the characters of a high spire, a short
body whorl and a short anterior canal, although Bruguiére himself recog-
nized the heterogeneous character of the genus, for he separated it into
three groups which are now properly recognized as distinct genera. Fur-
ther subdivision has been found necessary from time to time, until in
M. Cossmann’s Hssais de Paléoconchologie, volume 7, after the separa-
tion of several groups of family rank, we find seventeen genera, thirty-
one subgenera and forty-five sections.

Choosing Cerithium nodulosum BruguIBRE as the genotype, M. Coss-
mann lays especial stress upon the projecting tooth on the anterior por-
tion of the outer lip, and he restricts the genus so as to include those
forms in which this tooth crosses the opening of the canal. This ena-
bles him to place only two species within the genus, the genotype and
Cerithium erythreonense (= C. tuberosum), but a close study of the
anterior tooth seems to indicate that its importance as a basis for classifi-
cation has been greatly overestimated. It appears on the last portion of
the body whorl, a position in which the highest degree of variation in the
shell is to be expected, and features appearing at this stage should serve
as reasons for separating end members of evolutionary series, but not for
uniting species as genera, if the classification is to be a natural one—
that is, based on community of descent. The tooth is formed by the
more rapid growth of the anterior part of the outer lip, and when a
spiral is present on this part of the shell, it often determines the point
at which an extra amount of calcareous material is deposited. The de-

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 13

velopment of this tooth is extremely variable among individuals undoubt-
edly of the same species; for example, among six adult individuals of
C. ? nodulosum showing no trace of fracture, two develop this feature
to a very slight extent and do not form a tooth which crosses the aperture.

C. echinatum is referred to a different section on account of the less
development of this tooth, but certain individuals have the tooth devel-
oped to a greater extent than some specimens of C. nodulosum.

Not only is the tooth variously developed in species which are shown
by their ontogeny to be related, such as C. tuberosum and C. echinatum,
but it is strongly developed in species undoubtedly of different descent ;
for example, Pseudovertagus aluco and related species have such a tooth
very strongly developed, yet the wide difference between the ontogeny of
Pseudovertagus aluco and Cerithiwm tuberosum will, be readily appre-
ciated by comparing the figures of C. tuberosum in the first column of
plates 111 to vi with those of Pseudovertagus aluco in the fourth column
of the same plates.

Of the genera and subgenera of Cerithiide already established, there
will be considered in this paper only the Cerithiwm tuberosum group and
others closely related to it.

In the description of species which follow no attempt has been made
to give a complete synonymy. In each case the original description or a
reference to it is given, and also a reference to a good modern description.
Where necessary to make the identification of the species clearer, addi-
tional references are given. Descriptions are based on one individual
which may be considered typical of the species, but where variations such
as differences in color, in the number of varices and the like are charac-
teristic features, other individuals are considered. Measurements are
also from one individual, usually the largest of those referred to the
species. The method of taking measurements of the apical angle is sim-
ilar to that described by d’Orbigny [1842-1843, pp. 10-14], with the ex-
ception that in the case of convex or concave shells two measurements are
given representing the extreme angles obtained, and, as nearly as possi-
ble, the volution at which the change takes place. The sutural angle is
measured as described by d’Orbigny, holding the aperture of the shell
downward and taking the upper angle made by the suture with the right
side of the shell in dextral forms and the left side in sinistral forms.

14 ANNALS NEW YORK ACADEMY OF SCIENCES

IV. ONTOGENETIC DESCRIPTION OF SPECIES
A. RECENT SPECIES
1. Cerithium tuberosum Group
a. Kuropean Species
Cerithium tuberosum Columne
Plate 1; plate 1, fig. 4; plate 111, fig. 4; plate 1v, fig. 1; plate v1, figs. 1, 2.

1616. Cerithium [Buccinum] tuberosum Fasu CoLuMN&, De aquatilibus, pp.
Ty Bie

1843. Cerithium erythreonense LAMARCK, Animaux sans vertébres, éd. 2, IX,
292.

1855. Cerithium tuberosum Sowrrsy, Thesaurus Conch., II, 855, pl. 178, fig. 49.

1866. Cerithium tuberosum REEVE, Conch. Iconica, XV, pl. 1, fig. 5, No. 5.

1898. Cerithiwm erythrwonense Kospetr, Syst. Conch.-Cabinet von Martini u.
Chemnitz, Bd. I, Abth. 26, 78, pl. 15, figs. 2, 3.

1887. Cerithium erythreonense Tryon, Manual of Conch., IX, 123, pl. 20, fig. 16.

1906. Cerithiwm erythrewonense CoSSMANN, Essais de Paléoconch., VII, 67.

The original description by Fabii Columne is given under the discus-
sion of the genus.

MEASUREMENTS: Length, 64 mm.; greatest diameter, 29 mm.; apical angle,
34°, changing on the 9th volution to 29.5°; sutural angle, 91°.
Cotor: Pale brown or brownish yellow.

The protoconch is not preserved on any of the specimens obtainable.
The first volution retained is .?7 mm. in diameter, and this corresponds
in size with the first volution beyond the protoconch of Cerithium adan-
som. The surface features are entirely obliterated on this volution, but
the next shows traces of the ornamentation, which is apparently the same
as that of C. adansoni at the same age. The fourth volution has two
strong spirals, the upper of which defines the shoulder, with one spiral
intercalated between them. ‘There are also four equal spirals above and
two below the primary ones. All the spirals are crossed by ribs, of which
there are nine on this volution. On the succeeding volutions more
spirals are added on the shoulder and the lower slope of the whorls, and
their number is also increased by intercalation between those already ex-
isting. At about the eighth volution the spirals become much crowded,
and are raised into a strong ridge just below the suture. The same type
of ornamentation persists for eleven volutions, but on the twelfth the
lower of the two equal spirals becomes weaker, and the outline of the

WOOD, PHYLOGENY OF CERTAIN CERITHIIDEA 15

whorl changes from an obtuse angle to one both of whose sides stand at
angles of about 45° with the axis of the shell. This tendency increases
until, on the body whorl, the lower primary spiral is inconspicuous, and
the upper forms the most projecting portion of the strong nodes into
which the ribs have become contracted. The sub-sutural ridge above
described is, on this volution, raised at short intervals into a row of
smaller nodes, and on the lower portion of the body whorl there are three
strong nodose ridges formed, like the sub-sutural ridge, of groups of fine
spirals. On the under side of the body whorl ribs and nodes are nearly
obliterated along the surface upon which the animal rested when with-
drawn into its shell; but just beyond this area, on the side of the volution
opposite the outer lip, the surface is raised into a strong varix.

The aperture is oval, with a strong posterior tooth. The outer lip is
slightly flaring, with its margin crenulated by the spirals of the outer
surface. The lower portion of the outer lip grows more rapidly than the
upper portion, and the lowest of the nodose ridges is produced into a
toothlike process which, in some individuals, crosses the opening of the
anterior canal. The length of this process varies considerably in differ-
ent specimens of the species. The inner lip has a strong callus. The
anterior canal is long and comparatively narrow.

HORIZON AND LOCALITIES: Recent. Red Sea and Indian Ocean.
No. 20124, Columbia University collection.

REMARKS: Cerithium tuberosum is especially well adapted to serve as
a type of the group of shells to which it belongs, since it is a retarded
form passing through the various stages in its development slowly and
retaining primitive characteristics until a late period of its life.

Cerithium ? nodulosum Bruguiére
Plate 111, fig. 5; plate tv, figs. 4, 5.

1792. Cerithium nodulosum BrueuteRe, Hist. naturelle des Vers, Encycl. Méth.,
I, pt. 2, 478.

1887. Cerithium nodulosum Tryon, Manual of Conch., IX, 122, pl. 19, figs. 13,
ifs pk 20; te. 15.

1898. Cerithium nodulosum Kopett, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 76, pl. 15, fig. 1.

1906. Cerithium nodulosum CosSSMANN, Essais de Paléoconch. Comp., VII, 66,

MEASUREMENTS: Length, 95 mm.; greatest diameter, 47 mm.; apical angle,
37°; sutural angle, 84°.

Cotor: Grayish white, more or less closely covered with interrupted bands
and patches of dark brown,

16 ANNALS NEW YORK ACADEMY OF SCIENCES

The youngest volution available for study is 1.9 mm. in diameter, and
it is probable that several volutions have been broken away above this.
It has a sharply angled outline, with the most projecting portion slightly
above the middle of the whorl. It is ornamented with three strong, con-
tinuous spirals, the uppermost of which is stronger than the others. Two
finer spirals are present on the shoulder, and one is visible just above the
suture. The entire surface is roughened by exceedingly fine, thread-like
coste crossing the spirals at right angles. They are too fine and too
closely set to appear like ribs, and ribs of the usual kind are entirely
absent at this stage. The ornamentation remains similar in type, with
the intercalation of finer spirals between those already existing, until the
sixth volution, on which widely spaced ribs appear. At this stage the
volution is about 6 mm. in diameter. The fine spirals increase rapidly
in number, and on the later volutions the primary spirals seem to be
made up of clusters of finer spirals with the clusters separated by deep,
smooth grooves. At about the ninth volution the median of the three
spirals becomes almost as strong as the uppermost spiral, so that for two
or three volutions the obtuse angled outline of the whorl characteristic
of Cerithium is suggested. The upper spiral, however, soon becomes
again the most prominent one, and this tendency increases until, on the
body volution, this spiral forms the margin of very large, blunt, flat-
topped nodes, with the ribs nearly obsolete above and below them. On
the late whorls the finer spirals are sometimes confluent and the former
cluster becomes a broad, flattened ridge defined by a narrow groove on
either side. The body volution below the nodes bears three broad nodose
spirals.

The aperture is oval, with the outer lip flaring and thrown into strong
folds by the coarse spirals of the outer surface. The lowest of the spirals
on the body whorl is sometimes produced to such an extent that it forms
a projecting tooth which crosses the opening of the canal. The inner
lip hears a strong callus with a prominent tooth near the posterior portion
of the aperture. The siphonal canal is broad and deep and slightly bent
backward. :

HORIZON AND LOCALITIES: Recent. Moluccas, Philippines, Indian Ocean.

No. 40203, Columbia University collection.

The young individual figured is from the exhibition collection of the Museum
of Comparative Zodlogy.

Remarks: Although the adult of this species bears some resemblance
to Cerithium tuberosum, its development is unlike that of any species of
Cerithiide studied. The formation of a distinct shoulder so long before
the appearance of ribs and the presence of the fine coste crossing the

WOOD, PHYLOGENY OF CERTAIN CERITHIIDH 17

spirals are features which have not been observed elsewhere. So far as
the information at present available goes, it would appear that C. ? nodu-
losum is the sole representative known of a distinct genus, but it is left
for the present in the genus Cerithium, awaiting an opportunity to study
still younger stages of the shell and to obtain other shells which will
throw light upon this peculiar type of development.

Cerithium adansoni Bruguiére

Plate 1; plate 11, fig. 3; plate 111, figs. 2, 3, 4; plate rv, figs. 2, 3; plate v,
figs. 1, 2.

1757. “Le Cerite” Apanson, Histoire Naturelle du Sénégal, 152, pl. 10, fig. 2.

1792. Cerithium adansoni Brucutbre, Hist. Nat. des Vers, Ency. Méthod.,
I, pt. 2, 479.

1855. Cerithium adansoni Sowrersy, Thesaurus Conch., II, pl. 178, fig. 45.

1898. Cerithiimn adansoni Koseit, Syst. Conch.-Cabinet von Martini.u. Chem-
nitz, Bd. i, Abth. 26, 142, pl. 27, figs. 4, 5.

The following is Adanson’s description of “Le Cerite”:

Fabius Columna s’est servi du mot grec latinisé Cerithium pour defigurer
une espece du genre des coquillages que je vais décrire sous le nom commun
de Cerite.

La coquille de cette espéce n’a guéres que deux pouces de longueur et une
fois moins de largeur.

On n'y compte que douze spires, renflies dans leur milieu, qui est garni d’un
rang de boussettes assez grosses, élevées sur une cote parallel a sa longueur.
Le reste de leur surface est entouré de dix 4 douze petit filets peu élevés. La
seconde spire porte quelquefois un gros bourrelet sur la gauche.

La longueur du sommet surpasse presque une fois sa largeur et la premiére
spire.

L’ouverture est exactement ronde, et paroit beaucoup plus evasée que la
précédente, parce qu'elle se porte presqu’ entiérement hors de la coquille, sur
sa droite. Son canal inférieur est creusé en demi-cylindre, recouvert en partie
par une cdte assez grosse, elevée sur la base de la lévre gauche. Le canal
supérieur est reserré, et de moitié plus profond que large.

La lévre droit n’est pas sensiblement prolongée dans sa partie supérieure,
et elle ne forme pas l’auvent comme dans la premiére espéce.

La lévre gauche n’est pas non plus repliée comme la sienne; elle est recou-
verte seulement par une lame courte, mais @épaisse, et relevée en bas d’un filet
assez gros qui tourne en dedans de la coquille.

Sa couleur est blanche, sans melange dans les jeunes, et légérement tachée
de brun dans les vieilles.

Je n’ai remarqué dans cette coquille qu’ une légére variété, qui consiste en
ce que les boussettes des spires sont quelquefois assez longues et pointues:
cela se rencontre ordinairement dans les jeunes; et c’est vraisemblablement
le frottement qui les use et les arrondit dans les vieilles.

Cette espéce yit aussi dans la vase mais on ne la voit qu’en petite quantité
dans le fleuve Gambie, vis-A-vis le comptoir d’Albreda.

18 ANNALS NEW YORK ACADEMY OF SCIENCES

The description of this species given by Bruguiére is closely similar to
that of Adanson, and much of it is even worded in the same way. Prac-
tically the only addition made by Bruguiére was in giving the species a
binomial name.

MEASUREMENTS: Length, 48 mm.; greatest diameter, 3 mm.; apical angle,
50° to the eighth volution, changing to 31.5°; sutural angle, 72.5°.
Coton: White, sparingly dotted with pale brown.

The protoconch of Cerithiwm adansoni consists of about one and one-
fourth volutions. The ornamentation begins as two spirals crossed by
distant ribs on the first volution beyond the protoconch (plate 11, fig. 2).
The second volution bears three fine spirals on the shoulder. These
are increased by a fourth fine spiral on the third volution, and an
intercalated spiral appears between the two primary ones. Tertiary
spirals and those of higher order are soon developed, and these fine spirals
do not increase greatly in size, but they become extremely numerous, so
that the entire surface of the adult is covered with thread-like coste. On
the fourth volution, just below the upper suture, there is an elevation of
the surface to form a coarse spiral which carries with it the fine spirals
already existing. Later in the life of the shell other coarse spirals arise
in a similar manner on the shoulder and below the two primary spirals.
The lower of the primary spirals becomes gradually weaker and the upper
more prominent, until at about the sixth volution the outline of the
whorl has lost its vertical element formed by the two equal spirals and
has become an acute angle. On the next volution the center of the rib
becomes so prominent that it might almost be called a spine, and on this
volution also rows of large nodes are formed by the breaking un of the
coarse spirals just below the upper suture and ahove the lower one. On
the eleventh volution there are three coarse spirals above and three below
the central extremely prominent one, all of which are irregularly nodose.

The median spiral of the body volution is spinose on the dorsal side,
but on the ventral side the spines are represented by low nodes onlv.
Below the prominent spiral on the bodv volution there are six or more
coarse spirals with finer intercalated ones, and the whole is covered, like
the rest of the surface, with the fine costs described above.

The aperture is a broad oval in outline. The outer lip is thick, some-
what flaring, and crenulated by the snirals of the outer surface. The
inner lip has a thick callus. raised into a strong blunt tooth which, with
the outer lin, forms a short canal at the posterior end of the aperture.
The anterior canal is short and slightlv eurved. and its onening is nar-
rowed hy the rapid growth of the lower portion of the outer lip. This

WOOD, PHYLOGENY OF CERTAIN CERITHUDA 19

growth does not, however, form a distinct tooth as in Cerithiwm tuber-
osum and some forms of C. echinatum.

HoRIZON AND LOCALITIES: Recent. Senegal, west coast of Africa and spar-
ingly near the mouth of the Gambia River. M. Cossmann [1906, p. 66] as-
sumes that this shell is a fresh-water form, but this is hardly borne out by
the statement of Adanson, who collected the animals in their native locality.
According to his account of the habitat quoted above, it seems that the animal
is typically marine, and comparatively few individuals have migrated up the
Gambia River.

No. 20125, Columbia University collection.

Museum of Comparative Zodlogy, museum collection.

Remarks: This shell, from the protoconch to the seventh volution,
corresponds exactly in development with Cerithiwm tuberosum. It is,
however, a more accelerated shell, since the stage with two equal spirals
persists in C. tuberosum for ten volutions, while in C. adansoni this
feature is lost on the sixth volution. The adult of C. tuberosum cor-
responds approximately to the seventh volution of C. adansoni, but the
correspondence is not exact, for at this stage C. adansoni has not ac-
quired a sub-sutural row of fine nodes, while its ribs have become even
more spinose than those of C. tuberosum. C. adansoni is not to be re-
garded as a descendant of C. tuberosum, but rather the two are descended
from a common ancestor, (. adansoni passing through its ancestral stages
rapidly and adding new characters, while C. tuberosum is retarded in its
development and never attains the high degree of ornamentation charac-
teristic of the adult C. adansoni.

Be A

Cerithium echinatum Lamarck

1843. Cerithium echinatum Lamarck, Animaux sans vert., 6d. IT, TX, 291.

1887. Cerithium echinatum Tryon, Manual of Conch., IX, 123, pl. 20, figs. 25-27.

1898. Cerithium echinatum Koper, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 100, pl. 20. figs. 5-8.

1906. Gourmyia echinatum CossMANN, Essais de Paléoconch., VII, 69.

MEASUREMENTS: Length, 49.4 mm.; greatest diameter, 27.8 mm.; apical

angle to the ninth volution, 45°, changing to 37.5°; sutural angle, 82.5°.
Cotor: Grayish white, sometimes marked with transverse patches of brown,

which is deepest on the spirals.

The protoconch of Cerithium echinatum is much worn on the only
available specimen showing that feature, but so far as can be determined,
it is precisely like that of C. adansoni, and the first four volutions are
indistinguishable on the two shells. On the fifth volution there is less
contrast between the primary spirals and those of higher order than on

20, ANNALS NEW YORK ACADEMY OF SCIENCES

C. adansoni. In other words, the primary spirals are not so highly de-
veloped, and spirals of higher order are coarser. This difference persists
throughout the remainder of the shell growth. On the sixth volution,
beyond the protoconch, the upper of the two primary spirals becomes
more prominent. This tendency increases until, on the body volution,
the ribs have become contracted into spines, of which the upper primary
spiral forms the most projecting portion. The spirals of higher order
increase rapidly in number until they become so crowded that they
coalesce, forming broad, flattened ridges which are in places finely striated,
indicating the original spirals of which they are composed. On the body
whorl the uppermost spiral breaks up into fine nodes, and just before the
end of this volution three spirals on the shoulder become similarly no-
dose. On the lower slope of the volution there are also three strong
spirals which become nodose toward the end of the whorl. Spines are
absent from the under side of the body volution, as in C. adansona.

The aperture is broadly oval. The inner lip bears a strong callus,
with a well-developed tooth forming, with the outer lip, a short canal at
the posterior portion of the aperture. The anterior canal is short and
slightly curved. The outer lip is flaring, its margin being crenulated by
the spirals of the outer surface. The lower margin of the outer lip
grows more rapidly than the upper, forming a projection somewhat as in
Cerithium tuberosum, but not so strongly developed as in the latter
species. There is considerable difference in the degree to which this
feature is developed on several individuals of C. echinatum.

HorIzoN AND LOCALITY: Recent. Zanzibar.
No. 40181, Columbia University collection.

Remarks: This shell bears a strong resemblance to C. adansoni, but
differs in the coalescence of the fine spirals, which on C. adansoni remain
distinct throughout the life of the shell, covering all the coarser features
with fine thread-like lines. On (©. echinatum also nodes are developed
to a less degree, appearing only on the latest portion of the body volution.
The more rapid growth of the lower portion of the outer lip on C. echina-
tum is an important distinguishing feature, since it does not occur on
C. adansoni.

C. echinatum, as shown by its early development, is closely related to
C. tuberosum, but it is a more accelerated shell, since it loses the vertical
element from its outline on the sixth volution, instead of the tenth,
as in CO. tuberosum. While more accelerated than C. tuberosum, it is
more retarded than ©. adansoni, since it does not acquire nodes until
near the end of its life history.

(nPSaee

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 21
Cerithium menkei Deshayes
Plate vu, figs. 2, 3; plate vu, fig. 3; plate rx, fig. 2.

1865. Cerithium menkei DeESHAYES, Moll. Réunion, p. 97, pl. 9, fig. 15.
SST. Cerithiwn columna Tryon, Manual of Conch., 1X, 123, pl. 20, fig. 19.
1898. Cerithium menkei Kosreir, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 208, pl. 37, fig. 1.

MEASUREMENTS: Length, 29 mm.; greatest diameter, 16.5 mm.; apical angle
to the eighth volution, 47°, changing to 35°; sutural angle, 76.5°.

CoLtoR: Uniformly cream-colored, or occasionally having a few pale brownish
spots scattered irregularly over the surface.

This shell is thin and delicately sculptured, with all the features of
the surface ornamentation distinctly shown.

The protoconch is not preserved, but the first volution remaining,
which is probably the first beyond the protoconch, is ornamented by two
spirals and faint ribs only. ‘This volution has a diameter of .6 mm. On
the next volution three fine spirals appear on the shoulder. Intercalated
spirals are first developed on the third volution, and they increase rapidly
during subsequent growth until, on the body whorl, those of the fifth
order may be counted. ‘The two primary spirals remain of equal strength
for eight volutions, but on the later volutions the lower spiral becomes
weaker, until it is reduced to the size of a secondary spiral, and the out-
line of the whorl is changed from an obtuse angle to approximately a
right angle. At intervals on the later volutions of the shell one rib is
slightly stronger than the others, and on the body whorl there is one
strong varix. A sub-sutural band, as in C. tuberosum, is developed on
the ninth and later volutions. Toward the end of the body whorl this
band becomes tuberculate, and on the lower slope of this whorl two strong
spirals are developed.

The aperture is elongate oval, with a posterior tooth on the narrow
callus of the inner lip. The outer lip is flaring, crenulated by the spirals
of the outer surface. The anterior canal is comparatively long.

HORIZON AND LOCALITY: Recent. Indian Ocean.
No. 20126, Columbia University collection.

REMARKS: Cerithium menkei differs from C. columna in having a
thinner shell, finer and more delicate sculpture, broader and less widely
spaced ribs.

The development of the ornamentation of this shell is so closely par-
allel to that of OC. tuberosum that, taken in connection with the similarity
in the form of body and aperture, it leaves no room for doubt that the

29 ANNALS NEW YORK ACADEMY OF SCIENCES

two are developed from a common ancestor. This is clearly brought out
by a comparison of the figures of young whorls on plate vil, figs. 2, 3,
and plate 111, fig. 4.

Cerithium columna Sowerby

1855. Cerithiwm columna SowErsy, Thesaurus Conch., II, 855, pl. 178, figs.
_ 55-58.
1866. Cerithium columna REEVE, Conch. Icon., No. 2, pl. 1, fig. 2.
1887. Cerithium colwmna '.RYoN, Manual of Conch., LX, 123, pl. 20, figs. 17, 18.
1898. Cerithium colwnne KoseLtr, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 85, pl. 16, figs. 7, 8.

MEASUREMENTS: Length, 29.2 mim.; greatest diameter, 17.1 mim.; apical
angle, 41°; sutural angle, 87°.

CoLor: Ground, white or cream white, with irregular patches of dark reddish
brown, the amount of brown on different individuals varying greatly.

The shell is thick and heavy, with relatively coarse spirals and narrow,
sharp ribs.

The youngest volution preserved is 2 mm. in diameter. It bears two
strong, equal spirals with intercalated spirals of two higher orders and
fine spirals on the shoulder. All are crossed by ribs, which on the later
volutions of the shell become narrow, with wide interspaces. The orna-
mentation retains the same character, with an increase in the number of
intercalated spirals for the three succeeding volutions, after which the
lower of the two primary spirals becomes weaker, changing the outline of
the volution, as described above, from an obtuse angle to a right angle.
Varices occur on the later whorls to the number of about two to the
volution. The spirals become closely crowded just below the suture, and
there is a tendency toward the formation of a sub-sutural band, but it
never becomes well developed. On the later portion of the body volution
small nodes are developed on the stronger spirals.

The aperture is broadly oval, with a well-developed posterior tooth
and short, oblique anterior canal. ‘The callus of the inner lip is thick and
rather narrow. ‘The outer lip is flaring and crenulated.

HorIZON AND LOCALITIES: Recent. Indian Ocean, Japan, Oceanica.
No. 20127, Columbia University collection.

Remarks: This species is a near relative of C. menkei, differing in the
characters enumerated above and, like that species, reveals in its devel-
opment its relationship to C. tuberosum.

—

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 93

Cerithium citrinum Sowerby
1805. Cerithiuiw citravuui SoweRBy, ‘Luesaurus Conch., 11, 855, pl. 179, fig. 66.
1866. Cerithium citrinwie Reeve, Conch. lcon., No. 1, pl. 1, fig. 1.
1887. Cerithium citrinum TRYON, Manual of Conch., LX, 123, pl. 20, fig. 21.
sys. Cerithivui citruiuit IWOBELT, Syst. Conch.-Cabinet yon Martini u. Chem-
nitz, bd. 1, Abtu. 26, 110, pl. 22, fig. 23.

MEASUREMENTS: Length, 0J.50 min.; greatest diameter, 15.5 mm.; apical
angle, 37°; sutural angle, 87°.
COLOR: Creal white, with streaks and patches of pale brown.

‘Lhe youngest voiution preserved on this shell is 2 mim. in diameter,
and its ornamentation is similar to that of the fourth volution on UC.
menker. it has two strong equal spirais, one intercalated spiral and
five fine spirals on the shoulder. One spiral is on the lower slope of the
whorl. ‘lhe ribs on this species are broad and, for the first tive volu-
tions, broader than the spaces between them. ‘I'he two primary spirals
remain equal in strength for seven volutions, after which the lower spiral
is weaker, but the outline of the volution never becomes sharply angular,
as in the preceding species. ‘The secondary spirals of the shoulder and
the lower slope of the whorl become as strong as the primary ones, and
the outline of the volution becomes regularly curved. Extremely fine
spirals of higher order are rapidly introduced, while the primary and
secondary spirals are raised into ridges carrying the finer spirals with
them, so that the whole surface appears to be covered with bundles of
fine spirals having deep grooves between them. ‘The ribs disappear on
the body volution, with the exception of one strong varix on the side op-
posite the aperture, as is usual in shells of this group. Nodes are absent
from the entire surface.

The aperture is broadly oval. The callus of the inner lip is thick and
narrow, with a prominent posterior tooth. The anterior canal is long
and the margin of the outer lip thick and crenulated.

HorIzoN AND LOCALITY: Recent. Bird Islands, Pacific Ocean.
No. 20128, Columbia University collection.

REMARKS: Cerithium citrinum differs from C. columna in the more
delicate surface ornamentation, the rounded outline of the volutions and,
with the exception of one varix, the absence of ribs and nodes on the
body volution. It also has a longer anterior canal. This species differs
from C. menkei in the absence of sharply angular volutions and in the
disappearance of ribs on the body whorl.

24 ANNALS NEW YORK ACADEMY OF SCIENCES

Cerithium citrinum mut. bicolor Hombron et Jacques
1842-1853. Cerithiwm bicolor HomMpBron et Jace. Voyage au Pole Sud., pl. 238,
figs. 14, 15.
1887. Cerithium citrinum Tryon, Manual of Conch., 123, pl. 2, fig. 22.
1898. Cerithiwn citrinum Woseit, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. i, Abth. 26, 11x

MEASUREMENTS: Length, 29.7 mm.; greatest diameter, 16.8 mm.; apical
angle, 44°, changing to 30° on the last three volutions; sutural angle, 86°.
CoLor: Cream white with patches of a slightly darker yellowish tone.

The first two of the volutions preserved are precisely similar to those
of Cerithium citrimum. On the third volution the ribs become con-
tracted, leaving broad interspaces, as in C’. columna, but the spirals retain
the characteristic development of C. citrinwm—that is, bundles of spirals
with deep grooves between them. ‘This type of ornamentation is carried
still farther on the mutation bicolor, until, as early as the seventh volu-
tion, the interspaces are smooth and nearly or quite ag wide as the groups
of spirals themselves. The upper of the two primary spirals becomes
slightly stronger than the lower as early as the fourth volution, and the
two retain the same relative strength for seven volutions. The eighth
volution attains the angular outline characteristic of C. columna. All
the spirals of this form are prominent and sharply defined, even more
so than on either C. citrinum or C. columna. On the body volution all
the strong spirals break up into fine nodes.

The aperture is broadly oval, with a posterior tooth and short, oblique
anterior canal. ‘The outer lip is strongly crenulated. The callus of the
inner lip is strong and not closely applied to the surface of the shell.

HORIZON AND LOCALITY: Recent. Philippines.
No. 20129, Columbia University collection.

REMARKS: This shell has the prominent shoulder of C. columna, while
retaining the thin shell, fine sculpture and development of spirals char-
acteristic of C. citrinum.

Cerithium scabridum Reeve

1866. Cerithium scabridum RerveE, Conch. Iconica, XV, No. 52, pl. 8, fig. 52.

1887. Cerithium columna mut. scabridum Tryon, Manual of Conch., IX, 123,
pl. 20, fig. 20.

1898. Cerithiwu scabridum Kosert, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth:.26, 210; pl. 37, fig. 6.

MEASUREMENTS: Length, 20.5 mm.; greatest diameter, 11.4 mm.; apical
angle, 34.5°; sutural angle, 82.5°.

Cotor: White with the more prominent spirals sparingly touched with
brown.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 25

The youngest volution preserved probably corresponds with the fourth
volution of C. menket, being 2 mim. in diameter. This volution has two
strong, equal spirals and three intercalated ones. The shoulder has five
and the lower slope of the whorl one additional spiral. Ribs are present
to the number of eleven on this volution. The ornamentation resembles
that of Cerithium citrinuwm in being made up of bundles of fine spirals,
but the depressions between the groups are less deeply carved than in
that species. The two primary spirals remain equal for five volutions,
after which the outline of the volution becomes angular, but not sharply
so as in C. menkev. On this shell, as usual in this group, it is the upper
of the primary spirals which is most prominent. The ribs become weaker
on the body volution and disappear on the later portion of it. On this
portion of the shell, also, all the coarser spirals break up into rows of
small nodes. A large varix is present on the side of the body volution
opposite the aperture.

The aperture is broadly ova!, with a well-developed posterior tooth,
narrow callus and short anterior canal. The outer lip is finely crenu-
lated by the spirals of the outer surface and not flaring.

HORIZON AND LOCALITY: Recent. Both Reeve and Kobelt report the locality
of the species as unknown. The specimens in the collection of Columbia Uni-
versity referred to this species are from the Bird Islands, Pacific Ocean.

No. 20130, Columbia University collection.

Remarks: This little shell is nearest to C. citrinum, but it differs in
its smaller size, white color, less deeply carved surface ornamentation,
the more angular outline of the volutions and the short anterior canal.
From the mutation bicolor, it differs in size and color and in the less
prominently developed shoulder.

Cerithium mediterraneum Lamarck

1848. Cerithium mediterranewm LAMARCK, Animaux sans vert., IX, 313.

1855. Cerithium mediterraneum SoweErsBy, Thesaurus Conch., II, 865, pl. 178,
fig. 50; pl. 101, figs. 128, 131-133.

1866. Cerithium mediterranewm REEVE, Conch. Iconica, XV, No. 53.

1887. Cerithium rupestre Tryon, Manual of Conch., IX, 126, pl. 21, fig. 48.

MEASUREMENTS: Length, 25 mm.; greatest diameter, 12.4 mm.; apical angle,
39.8°, changing to 25° on the seventh volution; sutural angle, 77.5°.

Cotor: Cream white, mottled with streaks of yellow or brown. Color bands
usually passing transversely across the spirals, but when parallel with them
seeming to occupy the depressions between the spirals rather than their more
convex portions.

The youngest volution preserved is .9 mm. in diameter. This volution

26 ANNALS NEW YORK ACADEMY OF SCIENCES

is ornamented by two strong, equal spirals, with two finer spirals on the
shoulder and all the spirals crossed by ribs. The succeeding volution
has a fine spiral intercalated between each two of the three already exist-
ing, and more spirals are rapidly introduced on the later volutions. ‘Ihe
spirals on the adolescent and adult whorls of this shell are all flattened,
their limits being defined only by the exceedingly fine grooves between
them. ‘Ihe lower primary spiral begins to decrease in strength on the
sixth volution, and the seventh has a sharply angled outline. On this
volution a row of fine nodes is formed just below the upper and above
the lower suture. On the body volution the shoulder is lost, and the
surface is ornamented by five or more rows of low nodes.

The aperture is oval. ‘The callus of the inner lip is thick and has a
strong posterior tooth. ‘The outer lip is thick and smooth. ‘The an-
terior canal is short and slightly bent backward.

HORIZON AND LOCALITY: Recent. Mediterranean Sea.
No. 20131, Columbia University collection.

REMARKS: Cerithiwm mediterraneum has its nearest relative in C. citri-
num mut. bicolor. 1t differs in having flattened spirals not grouped
in bundles, as in the latter species. On the whorls having an angular
outline the reduced primary spiral becomes so much flattened that the
outline of the lower as well as the upper slope of the volution is nearly
a straight line. In the preceding species, which are similar to C’. medi-
terraneum, the lower primary spiral is always stronger and easily distin-
guishable from the secondary ones. From C. columna this species differs
in having finer surface ornamentation, with flattened spirals and broader
ribs and in the loss of the shoulder on the body volution.

The last five species and one variety, namely, C. menkei, C. columna,
C. citrinum and its mutation bicolor, C. scabridum, C. mediterraneum,
constitute a group of closely related forms. ‘They are evidently all de-
veloped from a common ancestor and for the early portion of their life
history follow the same path of development. The divergence observed
in the neanic and ephebic stages of growth are all due to differences in
the degree of development or in the grouping of the various features of
the surface ornament. In C. menkei the development of the spirals and
the sharply angled outline of the whorls are emphasized; in C. columna
the development of the shoulder and of the ribs are distinctive, and in
C. citrinum and its variety the grouping of the spirals in clusters is no-
ticeable. They might all be regarded as varieties of one species, as sug-
gested by Tryon, or their divergence in the adult stage might be con-
sidered great enough to entitle them to rank as distinct species. The

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE ri

latter method seems to the writer best to represent the degree of devel-
opment which these shells have reached.

Cerithium dialeucum Piilippi
1851. Cerithium dialeucum Puitirei, Abbildungen, III, 14, pl. 1, fig. 5.
1866. Cerithium diadleucwn Rerrve, Conch. Iconica, XV, No. 18.
1887. Cerithium dialeucum TRYON, Manual of Conch., IX, 130, pl. 23, figs.
87, 88.
1898. Cerithiuwm dialeucum IWoBeir, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 167, pl. 31, figs. 8, 9.
MEASUREMENTS: Length, 51.4 min.; greatest diameter, 15 mm.; apical angle,
45°, changing to 25.2° on the last two volutions; sutural angle, 79°.
CoLor: Grayish white on the spirals with alternating bands of dark reddish
or purplish brown in the grooves between the spirals.

The youngest volution preserved is 1.5 mm. in diameter, but it reveals
nothing of the development at this stage, for the ornamentation is nearly
obliterated on the first three volutions. The third volution, however,
indicates the presence of two strong spirals crossed by ribs. he fourth
volution has an oblique-angled outline formed by two primary spirals
and three intercalated ones. Spirals of the first, second and third orders
are present on the shoulder and all are crossed by prominent ribs, with
varices to the number of about three on a volution. ‘The different orders
of spirals on this shell are clearly indicated by a marked difference in
size. The two primary spirals remain of equal strength for about six
volutions, after which the lower becomes somewhat weaker and one of
the spirals on the shoulder becomes stronger, so that on the last two volu-
tions the shell has three strong spirals, of which the median one is the
most prominent, and intercalated spirals to the fourth order are also
present. ‘The whorls of the neanic shell are rounded in outline, and only
the later portion of the body volution becomes somewhat angular. The
lower slope of the body whorl bears six or more strong spirals with inter-
calated ones, all of which tend to become nodose toward the end of the
whorl.

The aperture is oval. The callus of the inner lip is narrow, with a
prominent posterior tooth. The anterior canal is oblique and of moder-
ate length. The interior of the outer lip is deeply grooved to correspond
with the spirals of the outer surface. The grooves of this surface are
white like the spirals, and the ridges are colored to correspond with the
depressions of the outer surface. A narrow margin of the outer lip is
thick, smooth and white.

HorRIZON AND LOCALITY: Recent. Philippines.
No. 20132, Columbia University collection.

s

ANNALS NEW YORK ACADEMY OF SCIENCES

ca)
10.0)

REMARKS: This shell is distinguished from all members of the Ceri-
thium columna group by the strong and regular variation in the width of
the spirals to correspond with their order of introduction. The regular
banding in color is also a distinguishing feature. The general form of
the shell, its early development and the form of the aperture all indicate
its relationship to the C. tuberosum group.

Cerithium album Hombron et Jacques

1642-1853. Cerithiwn album TompBron et Jacg., Voyage Pole Sud., V, 101, pl. 28,
figs. 22, 28.

1887. Cerithiwm echinatwn Tryon, Manual of Conch., IX, 124, pl. 20, fig. 26.

1898. Cerithium echinatwn KoBeLtT, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 102.

MEASUREMENTS: Length, 31.4 mm.; greatest diameter, 17.8 mm.; apical
angle, 52.5°, changing abruptly to 23° on the last two volutions; sutural angle,
AGids.

Cotor: White or cream white with occasional streaks of dark brown.

Youngest volution, 3 mm. in diameter, bearing the two strong spirals
always found in the young stages of this group, with three intercalated
spirals. Fine additional spirals are present on the shoulder and the lower
slopes of the whorl. The ribs are numerous and nearly as wide as the
spaces between them. Fine spirals are rapidly introduced, becoming so
crowded below the suture that they form a broad sub-sutural band which,
unlike that of Cerithium tuberosum, retains the slope of the remainder
of the shoulder. On the fifth volution preserved, which is probably the
ninth of a complete shell, this sub-sutural band breaks up into a row of
small nodes, and the ribs become ill-denfined, giving place to a row of
strong nodes on the upper of the two primary spirals. The angle of the
shoulder, except in the youngest stages, is very wide, and on the body
volution it disappears altogether, being replaced by strongly nodose
spirals, of which there are five on this volution with fine rows of nodes
between them.

The aperture is oval, with a well-developed posterior tooth and short,
oblique anterior canal. The outer lip is strongly fluted, and the callus of
the inner lip is narrow.

HORIZON AND LOCALITY: Recent. Baker’s Island, Pacific Ocean.
No. 20183, Columbia University collection.

Remarks: This species has been considered synonymous with Cerith-
tum echinatum, but it differs from the latter species in several important
respects. Beyond the young stages, the shoulder of C. album is never

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 29

well defined, and the neanic whorls lack altogether the strongly spinose
character of C’. echinatum at the same age. The apical angle of C. album
is much wider, and the abrupt change in the slope of the sides on the last -
two volutions is not found on C. echinatum. The youngest stages of this
shell are closely similar to those of the species already described, but in
the adult the ornamentation develops rows of small nodes instead of the
shoulder angle present on many species of the group.

Cerithium graciliforme Sowerby

1866. Cerithium graciliforme SowERBy, apud REEvE, Conch. Iconica, XV, No. 49.

1887. Cerithiwm eburneum Tryon, Manual of Conch., IX, 129, pl. 22, fig. 77.

1898. Cerithium graciliforme WKoseir, Syst. Conch.-Cabinet von Martini u.
Chemnitz, Bd. I, Abth. 26, 124, pl. 24, fig. 9.

MEASUREMENTS: Length, 24.2 mm.; greatest diameter, 9.7 mm.; apical angle,

90

35.3°, changing on the ninth volution to 26°; sutural angle, 86.7°.
CoLtor: White with occasional spots of. pale brown.

The youngest volution preserved is .5 mm. in diameter, but it is too
much corroded to show its form. The next volution is also much worn,
but shows that it has two equal spirals crossed by ribs. On the third
volution the same type of ornamentation continues, with three fine spirals
on the shoulder. A single spiral is intercalated between the two primary
ones on the fourth volution, and there are four fine spirals on the shoulder
and one on the lower slope of the whorl. On the fifth volution, three
varices are developed, while the ribs between them become much narrower.
Varices continue to be formed throughout the life of thé shell and con-
stitute a striking feature of its ornament. The shoulder becomes nearly
obsolete, and the ribs break up into nodes until, on the tenth volution,
the surface is marked by a strong varix and four rows of nodes, of which
the second below the suture is weaker than the others. This type of orna-
mentation continues for the remaining three volutions.

The aperture is broadly oval. A posterior tooth is present, but is not
strongly developed. The callus of the inner lip is thin, and the outer lip
is nearly smooth. The canal is short and slightly reflexed at the margin.

HORIZON AND LOCALITY: Recent. The locality of this species is not given in
any of the descriptions of it that have been published, and the specimen in
the Columbia University collection is also unlabeled.

No. 20134, Columbia University collection.

ReMARKS: This species resembles most closely Cerithium eburneum,
and is considered only a variety of that species by Tryon; but it differs
in its more slender form, nearly obsolete shoulder and in the great devel-

30 ANNALS NEW YORK ACADEMY OF SCIENCES

opment of varices. It differs also in color, being nearly white. The few
pale brown spots are visible only with a lens.

6. American Species

Cerithium eburneum Bruguiére

1792. Cerithium eburneum BruGuIPRE, Hist. Nat. des Vers, Encyclop. Méthod.,
I, pt. 2,,438.

1887. Cerithiwm eburneum Tryon, Manual of Conch., IX, 129, pl. 22, fig. 75.

1898. Cerithium eburnewm Koper, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 219, pl. 39, figs. 3-6.

MEASUREMENTS: Length, 25.7 mm.; greatest diameter, 11 mm.; apical angle,
34°, changing to 29.5° on the ninth volution; sutural angle, 85.5°.

Cotor: White, irregularly marked with patches of color which vary from
golden brown to dark reddish brown.

The youngest volution preserved, which is probably the first beyond the
protoconch, is .56 mm. in diameter. It has two equal spirals, which re-
main the only ornamentation of the shell for about one-fourth of a volu-
tion. Less accelerated individuals retain this ornamentation for a com-
plete volution. The next features to appear are ribs and two fine spirals
on the shoulder. Intercalated spirals are first introduced on the fourth
of the volutions preserved, and the same type of ornamentation continues,
with the addition of fine spirals for eight volutions. Beyond this the
ribs become ill defined and gradually break up into rows of nodes, which
are developed on all the strong spirals until, on the volution before the
last, there are five such rows. At about the ninth volution the lower of
the two primary spirals becomes weaker, while the upper remains strong
and defines a slight shoulder at about the middle of the volution. Varices
are irregularly developed with not more than two on a volution, and fre-
quently less than two.

The aperture is oval, and a posterior tooth is well developed. The
anterior canal is short and rather widely open. The outer lip is crenu-
lated, and the callus of the inner lip is thick and narrow.

HorIZON AND LOCALITIES: Recent. West Indies, Florida.
No. 20135, Columbia University collection.

REMARKS: The development of this species and its general form are so
closely similar to those of Cerithium tuberosum as to leave little doubt of
their descent from a common ancestor, in spite of the fact that the two
shells come from such widely separated localities as the West Indies and
the Red Sea. The American species of other genera, as well as Cerithium,

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 31
tall al =
show such strong evidence of relationship with European forms that we
must assume some at present unexplained means of intercommunication
between species of the east and west shores of the Atlantic. This connec-
tion probably existed at some earlier geological period, since Miocenic
species show the same similarity to European forms as do the recent
species.

Cerithium caudatum Sowerby

1855. Cerithium caudatwm. Sowrersy, Thesaurus Conch., II, 856, pl. 179, figs.
as 2:

1866. Cerithiwm caudatum ReEEveE, Conch. Iconica, XV, No. 16.

1898. Cerithiuwm caudatum Kosett, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 112, pl. 22, fig. 4.

MEASUREMENTS: Length, 31.5 mm.; greatest diameter, 14.2 mm.; apical
angle, 41°, changing to 29° on the last three volutions; sutural angle, 75°.

Cotor: Golden brown. Lighter in color at the apex and on the varices.
Margin of the outer lip white streaked with black.

The apex of the shell is much corroded. The youngest volution to
show the surface is 2 mm. in diameter, and has the ornamentation char-
acteristic of this group of ribs and two strong spirals. At this stage
intercalated spirals are already introduced between the two primary ones,
and spirals of at least two orders are present on the shoulder and on the
lower slope of the whorl. The surface ornamentation remains of the
same type, with the introduction of more spirals, until the eighth volu-
tion, after which the ribs become discontinuous and the stronger spirals
break up into nodes. On this volution there is a sub-sutural row of
nodes, and each of the two primary spirals also forms a row of nodes.
The outline of the volution is an obtuse angle, with a sloping or concave
upper surface and vertical sides. On the ninth volution preserved the
finest of the spirals have become obsolete, and between the rows of nodes
the spirals are comparatively few and coarse, with narrow interspaces.
On the body volution the nodes of the lower primary spiral hecome very
small, no larger than those of the secondary spirals. This volution has
one row of strong nodes—those of the first primary spiral—a row of sub-
sutural nodes somewhat smaller and three rows of fine nodose spirals on
the lower slope of the whorl. The intermediate spirals are crenulated,
but not distinctly nodose.

The aperture is oval and the callus of the inner lip is thin, with a well-
developed posterior tooth. The outer lip is distinctly flaring and finely
crenulated along its outer margin. The anterior canal is short and
widely open.

32 ANNALS NEW YORK ACADEMY OF SCIENCES

HorRIzoN AND LOCALITY: Recent. Island of Guadeloupe.
No. 20136, Columbia University collection.

The shells of the Cerithiuwm tuberosum group, although differing greatly
in size, have a general similarity in form and in the essential character-
istics of the aperture. Their variation is expressed most strongly in the
features of the surface ornamentation. These features consist of spirals
of the first and higher orders, ribs, nodes which may develop into spines,
and a shoulder varying in extent of development and in form. In order
to bring out more clearly the relation between these shells as expressed in
their surface ornamentation, they have been plotted in diagrammatic
form, arbitrary signs being chosen to represent certain features of the
ornamentation. On plate 1 the numbers at the left of the page indicate
the volutions, the protoconch being numbered one. The protoconch,
when present, is represented by a circle. The spirals are represented as
horizontal lines, for while they are actually longitudinal elements, on the
shell they appear horizontal, and the diagram being intended merely to
represent certain features in graphic form, it retains the line most readily
associated in the mind with what is seen on the shell. For a similar
reason ribs are represented as vertical lines. Secondary spirals and those
of higher order are represented by two horizontal lines. Nodes are indi-
cated by dots, and the outline of the volution is represented by the lines
which would be used in drawing its two upper slopes—that is, an obtuse
angle changing to a right angle to agree with the development of certain
shells. The diagram is intended to represent resemblances and differ-
ences in a general way only. It records the introduction of spirals, ribs
and nodes, but does not attempt to show the different kinds and degrees
of development which they attain or such features as size, degree of em-
bracing of the whorls, etcetera. More complete details are given in the
descriptions and figures of the different species.

The diagram brings out the fact that some species are more retarded
than others; for example, Cerithiwm menket is a more retarded shell than
C. adansont, as shown by the fact that on the former species the change
in the outline of the whorl does not take place until the ninth volution,
and nodes are not acquired until the last volution, while both these
changes occur much earlier on C. adansoni. A similar comparison has
already been made between C. tuberosum and C. adansoni.

The diagram also shows differential acceleration and retardation of re-
lated species as in (. echinatum and C. graciliforme. On the former the
oblique-angled outline is lost on the seventh volution, while retained until
the tenth on the latter. Nodes are, however, acquired on the ninth volu-
tion of C. graciliforme, and do not appear until the twelfth volution of

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 33

vo

C. echinatum. As compared with C. graciliforme, therefore, C. echina-
tum is accelerated in the acquisition of the sharply angled outline of the
volution, but retarded in the development of nodes.

A marked similarity in the early development of these species is well
illustrated by the diagram. If a card be placed over the lower part of it
the eye is at once struck by the uniformity of the figures; moving the
card downward, differences begin to appear, becoming wider as repre-
sentations of the adult stages are reached. The divergence would be even
more marked if all the features of the shell could be indicated, instead
of the mere presence or absence of the five features represented.

2. Genera and Species of Recent Shells closely related to the Cerithium
tuberosum Group

Genus Vulgocerithium Cossmann

1906. Vulgocerithium CosSMANN HEssais de Paléoconch. Comp., VII, 77.

Genotype Cerithium vulgatum BRUGUIERE:

This genus is closely related to Cerithium sens. str. The early stages
of the genotype Cerithium vulgatum are closely similar to those of C.
tuberosum. 'The adult differs in a number of rather constant features
and therefore may be considered distinct. ‘The surface ornamentation
of the adult shell is characterized by the development of ribs or large
nodes, a sub-sutural row of smaller nodes, and by the coalescence of the
fine spirals into flattened bands defined by extremely narrow grooves.
The margin of the anterior canal is usually slightly reflexed.

M. Cossmann’s main points of difference from Cerithiwm sens. str. are
not only the elongate form of the shell and characteristic surface orna-
ment, but especially the form of the aperture. The absence of the more
rapid growth on the anterior part of the outer lip, which forms a project-
ing tooth in some species of Cerithium, is considered of most importance,
and the shorter siphonal canal and less flaring outer lip are also men-
tioned.

Vulgocerithium vulgatum Bruguwiére

1757. Le Goumier ADANSON, Histoire Naturelle du Sénégal, 1757, p. 156, pl. 10,
fig. 3.

1792. Cerithium vulgatum Brueutére, Dictionaire, No. 13.

1855. Cerithium vulgatwn Sowersy. Thesaurus Conch., IT, 864, pl. 178, fig. 43 ;
pl. 179, fig. 67.

1898. Cerithium vulgatwn Kosert, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I; Abth. 26, 87, pl. 17, figs. 1-8; pl. 18, figs. 1-4.

1906. Vulgocerithium vulgatum CossMANN, Essais de Paléoconch. Comp., VII,

Wie

34 ANNALS NEW YORK ACADEMY OF SCIENCES

MEASUREMENTS: Length, 63.7 mm.; greatest diameter, 21.4 mm.; apical
angle, 26.5°, changing to 23° on the twelfth volution; sutural angle, 88°.

Cotor: Background of bluish white, marked by numerous spiral bands of
reddish brown, which on the young shell is deepest in the grooves between
the spirals, but on the later and adult whorls irregular patches of color cover
most of the surface.

The only specimen studied which retains the protoconch is somewhat
worn at the apex, but the protoconch appears to be like that of Cerithium
adansoni. The second and third volutions are so similar as to be well
illustrated by the drawings of these two whorls on C. adansoni (plate 111,
figs. 3, 4), but the shell at this age is about twice the size of C. adansom
at the same age. The fourth volution is like that of C. adansoni, except
that about every third rib is much larger, forming a strong varix. ‘These
varices occur at gradually wider intervals up to the eleventh volution,
when they disappear from the specimen described. The presence of
varices is a variable feature, since in a series of specimens otherwise sim-
ilar the varices are more prominent and persist for a longer time on some
specimens than on others. Except for the presence of varices, the surface
ornamentation is like that of Cerithium tuberosum to the seventh volu-
tion, when small nodes appear on the sub-sutural band, one at the end of
each rib. Beginning with the ninth volution, the lower of the two pri-
mary spirals becomes gradually less prominent and the ribs become less
well marked, until on the twelfth volution the upper of the two primary
spirals only is prominent, forming a row of nodes slightly above the mid-
dle of the volution. The ribs, as such, have disappeared, being replaced
by the two rows of nodes. Spirals of secondary and higher orders in-
crease rapidly in number, and on the later whorls the finest spirals become
confluent, producing broad, flattened bands, with extremely narrow de-
pressions between them. On the body volution below the lower row of
strong nodes from three to five large spirals are faintly nodose.

The aperture is elongate oval, with a distinct but not very prominent
tooth defining the posterior canal. The outer lip is slightly flaring and
shows faint crenulations. The callus of the inner lip is thin. The an-
terior canal is wide and short, with its margin slightly reflexed.

HORIZON AND LOCALITIES: Recent., Mediterranean Sea, west coast of Africa,
and southward to Senegal.
No. 201387, Columbia University collection.

REMARKS: Individuals of this species vary somewhat in the width of
the apical angle, in the strength and spacing of the nodes, and the extent
to which the fine spirals coalesce and become flattened. At present the

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 35

species is made to include many synonyms and a large number of varie-
. ties, some of which, with a more detailed study of the shells, may prove
to be distinct species.

The close similarity of the young stages of this shell to those of Cerith-
tum tuberosum has already been referred to, but the very considerable
divergence at an early period of the ontogeny entitles it to rank as a dis-
tinct, though closely related, genus.

Vulgocerithium breve sp. nov.

MEASUREMENTS: Length, 34.1 mm.; greatest diameter, 15 mm.; apical angle,
43°, changing to 25.5° on the last two volutions; sutural angle, 76.2°.

Coton: Grayish white, mottled with dark brown. Bands of dark brown
occupy the depressions between the spirals.

The apex of this shell is much worn. The youngest volution to show
the surface ornamentation is 2 mm. in diameter and has the two strong
spirals, as in the young of V. vulgatum. At this stage intercalated spirals
are present, both between the primary spirals, on the shoulder and on
the lower slopes of the volutions. On the sixth volution of those pre-
served the ribs become especially prominent at the level of the upper
primary spiral, and a sub-sutural row of nodes is also developed. On the
whorl before the last the center of the rib becomes very prominent, and
on its lower slope the spirals have a tendency to coalesce and become flat-
tened, but this tendency is never carried very far on this species. On the
body volution the ribs become weaker and the sub-sutural row of nodes
stronger, until the two are of about equal strength.

The aperture is broadly oval, and the callus of the inner lip is thin, with
a prominent posterior tooth. The outer lip is slightly flaring and faintly
crenulated. The anterior canal is short, with its margin slightly re-
curved.

HORIZON AND LOCALITY: Recent. The specimens in the collection of Colum-
bia University were collected by D. M. Sankey in deep water off the mouth of
Grand River, northwest Mauritius.

No. 20138, Columbia University collection.

Remarks: The species is distinguished from Vulgocerithium vulgatum
by its shorter form, wider apical angle and heavier and more prominent
nodes, which make the outline of the volutions sharply angular. The
shell is also thicker and the spirals are more rounded than is usual with
V. vulgatum,

36 ANNALS NEW YORK ACADEMY OF SCIENCES

Vulgocerithium plicatum Philippi

1836. Cerithium plicata PHiviepr, Enum. Moll. Sicil., p. 192.
1887. Cerithium vulgatum Tryon, Manual of Conch., p. 126.

MEASUREMENTS: Length, 25.1 mm.; greatest diameter, 1.4 mm.; apical angle,
42°, changing to 24° on the last three volutions; sutural angle, 78°.
Coton: Background white, thickly mottled with yellow and golden brown.

The apex of the shell is much corroded, but a volution 1 mm. in diam-
eter shows that it possesses ribs and two spirals. The fifth volution is
the first to show the ornamentation plainly, and on this the spirals are
broad, but not greatly flattened, and the oblique-angled outline is still
retained. The embracing of the whorls is so great as to nearly cover the
lower slope of the whorl. The succeeding volutions develop a sub-sutural
row of nodes and the ribs are strongly defined. The upper primary
spirals remain always the more prominent, and the vertical element in the
outline of the shell disappears at about the eighth volution. The adult
ornamentation consists of strong ribs, which are most prominent at the
level of the first primary spiral, and a sub-sutural row of nodes. The
spirals are broad and somewhat flattened, with narrow depressions be-
tween them. On the body volution the ribs become narrow, crowded
and so low as to be nearly obsolete. The sub-sutural row of nodes is here
the most prominent feature of the ornamentation.

The aperture is oval, and the callus of the inner lip is thick, with a
well-defined posterior tooth. The outer lip is thick and smooth, with an
entire margin. The anterior canal is short and widely open.

HorIzON AND LOCALITY: Recent. Locality unknown.
No. 40237, Columbia University collection.

Remarks: Vulgocerithium plicatum has been regarded by Tryon as a
variety of Vulgocerithium vulgatum, but it differs from that species in
its smaller size and in its more continuous and more prominent ribs, with
their most convex portion at the center of the volution instead of above
the center. It also has broader and more rounded spirals, and the ante-
rior canal is proportionally shorter.

This species is related to the V. vulgatum group in the development of
the young whorls and in the general form of the shell and of the aperture.
The sub-sutural row of nodes and the ribs are the most noticeable features
of the ornamentation.

3

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 37

Vulgocerithium gracile Philippi

1836. Cerithium gracilis Putrpr1, Hnum. Moll. Sicil., p. 193.
1887. Cerithium vulgatum Tryon, Manual of Conch., p. 126, pl. 21, fig. 43.

MEASUREMENTS: Length, 30.8 mim.; greatest diameter, 11 mm.; apical angle,
39.5°, changing to 17° on the last three volutions; sutural angle, 82.5°.

Cotor: Yellowish white, mottled with reddish brown, which usually passes
in sinuous lines across the spirals.

The ornamentation is entirely obliterated on four volutions of the best
specimen available. The fifth volution has the usual two strong spirals,
and there are at this stage three intercalated spirals, with at least four
on the shoulder and two on the lower slope of the volution. All the
spirals are crossed by ribs, and varices occur to the number of about three
to the volution. A similar type of ornamentation persists to the seventh
volution. At this stage the spirals are still distinct, and the embracing
of the whorls is loose enough to leave a well-marked slope below the lower
strong spiral. On the next two volutions the finer spirals gradually
coalesce with the coarser ones, which then become broad and flattened.
The ribs between the varices become very narrow, and a sub-sutural row
of nodes is developed. The adult ornamentation is characterized by
numerous narrow ribs projecting in a sharply pointed but not very promi-
nent node at the level of the first primary spiral. The slight shoulder is
concave and the lower slope of the whorl gently convex. A sub-sutural
row of nodes is present on the adult whorls, and a row of fine nodes ap-
pears just above the suture. The ribs become nearly obsolete on the body
volution, being represented by two rows of nodes.

The aperture is of the type usual in this group, with an oval outline, a
narrow callus and a posterior tooth. The outer lip is slightly flaring,
and the anterior canal is a little longer than in the last species, with a
narrow opening and slightly reflexed margin.

HorIZON AND LOCALITY: Recent. Locality unknown. '
No. 20139, Columbia University collection.

_ Remarks: The species has been referred to Vulgocerithium vulgatum,
but it is distinguished by its smaller size, proportionally coarser and more
rounded spirals and by the more sharply pointed form of the main row
of nodes. The spirals below the slight shoulder become rounded and
irregularly nodose, instead of flattened and inconspicuous, as in V. vul-
gatum.

The shell bears a close resemblance to the last species described, but it
differs in several important respects. The development is much more
retarded than that of V. plicatum, since the coalescence of the spirals does

38 ANNALS NEW YORK ACADEMY OF SCIENCES

not begin until the seventh volution, as compared with the fourth volu-
tion on the preceding species. The embracing of the whorls is not so
close as on V. plicatum. The adolescent and adult stages are distinguished
by the much smaller nodes of the present species and by the form of the
node, which is sharp and pointed at the apex in V. gracile, as compared
with the blunt but more prominent and more elongate nodes of V. plica-
tum. The anterior canal also differs in being longer, narrower and
slightly recurved.
Vulgocerithium adenense Sowerby

1866. Cerithium adenense SowERBY, apud REEVE, Conch. Iconica, XV, No. 89.
1887. Cerithium adenense Tryon, Manual of Conch., IX, 124, pl. 20, fig. 30.
1898. Cerithium adenense KosBeir, Syst. Conch.-Cabinet von Martini u. Chem-
nitz, Bd. I, Abth. 26, 196, pl. 35, fig. 12.
MEASUREMENTS: Length, 23.2 mm.; greatest diameter, 8.4 mm.; apical angle,
32.5°, changing to 21° on the last four volutions; sutural angle, 83.5°.
Cotor: Yellowish or grayish white, with ill-defined sinuous lines of reddish
brown crossing the spirals.

The apex of the shell is broken away. The youngest volution studied
is 1.4 mm. in diameter and has the usual two strong spirals, with one
intercalated spiral and one or two spirals on the shoulder. Well-developed
ribs cross all the spirals. ‘The ornamentation remains of the same type,
with the addition of spirals for the next three volutions. On the fifth of
the volutions preserved a sub-sutural row of irregular, low nodes is devel-
oped, and the upper primary spiral forms sharp-pointed nodes where
crossed by ribs. On the later volutions the coarser spirals become broad
and flat, with fine grooves between them, and the finer spirals become
obsolete. The adult ornamentation is that of widely spaced ribs, which
are almost spinose where crossed by the upper primary spiral. The upper
slope of the rib is concave and the lower slope straight or slightly convex,
which gives the center of the rib the appearance of an upward-pointing,
blunt spine. There are three rows of finely nodose spirals on the lower
slope of the body volution.

The aperture is elongate oval. The callus of the inner lip is moder-
ately thick, with a well-developed posterior tooth, and the outer lip is
thin. The anterior canal is short and widely open.

HORIZON AND LOCALITIES: Recent. Island of Karak, Persian Gulf, Gulf of
Aden.
No. 20140, Columbia University collection.

Remarks: This little species is nearest to V. vulgatum but is distin-
guished by the great difference in the size of the shell and the size and

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 39

extreme sharpness of the principal row of nodes, which give the volution
a distinctly angular outline. The sub-sutural row of nodes is less well
defined than on V. vulgatum.

The species is distinguished from V. plicatum and V. gracile by its
sharp nodes and the greatly flattened spirals.

B. PLEISTOCENIC SPECIES OF VULGOCERITHIUM
Vulgocerithium vulgatum

M. Cossmann figures, on plate 3, fig. 14, of his Essais de Paléconcho-
logie, a specimen from the Pleistocenic of Saix, which he refers to this
species. It is smaller than the normal recent individuals, and the nodes
of the principal row are prominent and somewhat widely spaced.

C. PLIOCENIC SPECIES OF CERITHIUM

No specimens of the Cerithium tuberosum group from the Pliocenic of
the Eastern Hemisphere are available for study, and the information fur-
nished by the literature is meager.

Cerithium crenatum Broccut, figured in Quenstedt’s Petrefaktenkunde
Deutschlands, plate 204, fig. 46, is of a small specimen from the Pliocenic
of Asti, which may belong in this group. It has the oval aperture, pos-
terior tooth, and crenulated outer lip of Cerithiwm sens. str. It also has
in the young stages two rows of nodes which are stronger than the others,
but in the absence of specimens it is impossible to be sure that it is cor-
rectly placed here.

In the American Pliocenic several species occur which apparently be-
long in this group. Of these only two actual specimens were obtainable,
but good figures and descriptions aid in determining the relationaship of
others.

Cerithium callisoma Dall
Plate vil, fig. 1; plate vii, figs. 1, 2; plate rx, fig. 1.

1892. Cerithiwm callisoma Dati, Trans. Wagner Free Institute of Sci., III,
pt. 2, 282, pl. 14, fig. 8.

MEASUREMENTS: Length, 20.8 mm.; greatest diameter, 8 mm.; apical angle,
35°, changing to 26° on the last three volutions; sutural angle, 80°.

The youngest volution preserved on the specimens studied is .4 mm. in
diameter and has three spirals, of which the two lower are equal in size
and stronger than the upper one. Ribs are also present at this stage.

40 ANNALS NEW YORK ACADEMY OF SCIENCES

On the fourth of the volutions preserved one spiral is intercalated between
each pair of primaries and the upper primary spiral becomes weaker,
making the shoulder more pronounced. The sixth volution has three
fine spirals intercalated between the two strong primary ones, with one
above and one below the third primary spiral. The lower slope of the
volution has at this stage two spirals, one stronger than the other. The
same type of ornamentation persists throughout the growth of the shell,
with an increase in the number of spirals, which vary in strength accord-
ing to the order of their introduction. The third primary spiral on the
shoulder remains always stronger than any secondary spiral, but not so
strong as the other two primaries. The latter become very prominent
and produce the well-defined oblique-angled outline of the volution so
characteristic of Cerithium tuberosum.

The aperture has the usual oval form of the shells of this group, with
a narrow, thick callus and prominent posterior tooth. 'The anterior canal
is short and widely open.

HorIZON AND LOCALITY: Pliocenic of the Caloosahatchie beds, Florida.
No. 12569, American Museum collection.

Remarks: The first three volutions preserved on this shell recall the
seventh, eighth and ninth volutions of the Eocenic species, Cerithium
retardatum (plate Iv, fig. 10; plate v, fig. 9). On the latter shell three
spirals are developed, the two lower of which are stronger than the upper,
and the first intercalated spiral appears between the strong spirals. A
similar development is seen on C. callisoma, but it is more accelerated
than C. retardatum, since its shoulder is distinguishable from the first,
while C. retardatum never acquires a distinct shoulder, but retains the
primitive rounded outline of its volutions throughout life.

C. callisoma is most closely related to the recent species C. tuberosum,
but it is more primitive than the latter species, since it retains the oblique-
angled outline of the volutions throughout life without a trace of weaken-
ing of the lower spiral, while on C. tuberosum the lower primary spiral
becomes gradually less prominent, until on the body volution the outline
is sharply angular. The resemblance of the adult C. callisoma to the
young C. tuberosum is most striking, and if the latter species were from
a less distant locality, we might at once assume it to be the Pliocenic an-
cestor of C. tuberosum. As it is, we may suppose that (C. callisoma is
the American representative of this ancestor, which existed in the vicinity
of the Red Sea or the Indian Ocean, but has not yet been recorded from
that locality.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 41

Cerithium floridanum Mérch

1876. Cerithium floridanwn More, Malacologia Bliitter, XXIII, 114.
1892. Cerithium floridanum Day, Trans. Wagner Free Institute of Sci., Phila.,
III, pt. 2, Dee., 282, pl. 14, fig. 10.

MEASUREMENTS: Length, 34.2 min.; greatest diameter, 14 mm.; apical angle,
29°, changing to 22° on the twelfth volution; sutural angle, 86°.

The protoconch of the specimen studied is much worn, but is appar-
ently of the same form as that of Cerithiwm adansoni. The succeeding
three volutions are too much worn to show the ornamentation. The first
volution on which surface features appear distinctly is the fifth, which
has a diameter of 1.9 mm. It bears ribs and two strong spirals. The
shoulder is long and has three fine spirals, with a sub-sutural band com-
posed of two elevated spirals. A single spiral is intercalated between the
two strong ones, and the lower slope of the volution is very short. The
earlier whorls of the shell bear an irregular number of varices averaging
about two or three on a volution. On the sixth and seventh volutions the
sub-sutural band gradually breaks up into a row of nodes and the spirals
become larger, but do not increase rapidly in number. On the eighth and
ninth volutions the larger spirals become nodose where crossed by the ribs,
and on the next volution the nodes of the sub-sutural row and those of
the first primary spiral become larger than the others and of equal
strength. At the same time the nodes of the second primary spiral be-
come weaker. On the two succeeding volutions the large nodes just
below the suture and those of the upper primary spiral are in line verti-
cally, forming distinct ribs, while the nodes of the lower primary spiral
are small and twice as numerous as those of the upper row. ‘The spirals
on both the shoulder and lower slopes of the whorl alternate in strength
according to their order of introduction and are strongly defined by the
deep, narrow grooves between them. On the thirteenth and last volution
the nodes of the lower primary spiral become very small and numerous—
a mere line of beading around the shell.

The body volution and the aperture are much broken, but the inner lip
is preserved, showing that it has a thick callus with a blunt posterior
tooth, and the anterior canal is short and rather widely open.

HorIzoN AND LOCALITIES: Pliocenic. Caloosahatchie beds and Osprey, Man-
atee County, Florida.
No. 12568, American Museum collection.

ReMarKS: The adult ornamentation of this little shell shows some
variation from the figure given by Dall [1892, plate 14, fig. 10] in the

42 ANNALS NEW YORK ACADEMY OF SCIENCES

marked difference in the strength of the subordinate spirals and in the
more angular outline of the adult volutions, but the shell agrees with the
description and figure in essential respects. Its early development and
the general character of its adult features show it to belong undoubtedly
to the Cerithium tuberosum group.

Cerithium glaphyrea Dall

1892. Cerithiuwm glaphyrea Dawu, Trans. Wagner Free Institute of Sci., Phila.,
III, pt. 2, p. 283, pl. 14, fig. 4.

MEASUREMENTS (Dall): Length, 16 mm.; greatest diameter, 6 mm.; REMAIN-
ING MEASUREMENTS FROM FIGURE: Apical angle, 23°; sutural angle, 88°.

No specimen of this species has been obtainable, but from the original
description and figure the following features of interest in this connection
may be determined. From the figure it appears that the shell has two
spirals stronger than the others, with fine spirals between the two primary
ones and on the shoulder. A third strong spiral on the shoulder becomes
nodose, but is not so strong as the two main spirals. All the spirals are
crossed by numerous closely set ribs. The two strong spirals remain of
equal strength and continue to form an oblique angle for the whorl until
the body volution is reached, when the lower of the two becomes weaker.

The aperture is of the type usual in the Cerithiwm tuberosum group,
with a narrow callus and strong posterior tooth, flaring, crenulated outer
lip and short anterior canal.

HorIzON AND LOCALITY: Pliocenic of the Caloosahatchie beds, Florida.

REMARKS: This species has a strong fundamental resemblance to Ceri-
thiwm callisoma in the form of the body and of the aperture, and in the
persistence of the oblique-angled outline of the whorls formed by two
strong spirals with a weaker one on the shoulder. The most striking dif-
ference is in the very numerous ribs of C. glaphyrea, which are so closely
set as to appear like rows of nodes where crossed by the coarser spirals.
C. glaphyrea appears to have the essential characteristics of the 0. tuber-
osum group, but probably represents a lateral branch from the main line,
expressing its divergence in the development of numerous ribs.

Cerithium glaphyrea mut. litharium Dail

1892. Cerithiwm glaphyrea var. litharium Datu, Trans. Wagner Free Institute
of Sci., Phila., III, pt. 2, 284, pl. 14, fig. 9.

MEASUREMENTS (Dall): Length, 19 mm,; greatest diameter, 6.5 mm.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 43

v0

The mutation litharium evidently belongs to the same phyletic series
as the species to which it is related, differing only in minor features of
the ornamentation, such as more prominent nodes and additional rows of
fine beading.

Cerithium algicola ADAMS and C. muscarum Say, from the character
of their apertures and the general appearance of the shells, seem to be
related to this group, but in the absence of specimens and with very im-
perfect figures, it is impossible to be certain of their position.

D. MIOCENIC SPECIES
1. Cerithium.

So far as can be determined from the literature, the Miocenic of the
Eastern Hemisphere furnishes few specimens of the Cerithiwm tuberosum
group. This is due doubtless to lack of preservation, rather than to a
paucity of species existing during that period.

Cerithium bronni PartscH, of the Miocenic of the Vienna Basin, may
possibly belong here. [See Hérnes and Partscn, 1856, plate 42, figs.
12a, b.] The figure, which gives no clue to the ornamentation of the
young shell, is insufficient evidence for placing the shell definitely, but
the aperture corresponds with that of C. tuberosum, and the ornamenta-
tion of the adult is similar in type to that of other species of Cerithium
sens. str.

An unnamed variety of C. crenatum Broccut is mentioned by HérnEs
and PartscH [1856, p. 409] as occurring in the Miocenic of the Vienna
Basin. According to their figures [/oc. cit., plate 42, figs. 13, 14], the
shell has the adult characteristics of this group, but the features of the
young shell cannot be determined from the figures.

Cerithium mediterraneum, described with recent species of Cerithium,
is recorded by Hérnes and Partscu [1856, p. 393] from the Miocenic
of the Vienna Basin.

Cerithium calculosum Basterot

1825. Cerithium calculosum BastrrRotT, Mem. géol. sur les environs de Bor-
deaux, p. 58, pl. 3, fig. 5.

MEASUREMENTS: Length, 29.8 mm.; greatest diameter, 14.1 mm.; apical
angle, 37.2°; sutural angle, 79.3°.

The protoconch is absent from this shell, but the youngest volution
preserved is probably the first beyond the protoconch, and it is 1 mm. in
diameter. This volution is ornamented by ribs and two equal spirals.

44 ANNALS NEW YORK ACADEMY OF SCIENCES

The second volution is like the first, except that it has a third weaker
spiral just below the suture and numerous ribs are present at this stage.
On the sixth volution of those preserved the sub-sutural spiral becomes
nearly as ‘strong as the two primary spirals, and all three become strongly
nodose where crossed by the ribs. On the next two volutions the shoulder
practically disappears, and the volution seems to be ornamented by three
rows of strong nodes with intercalated spirals between them. Varices
are irregularly developed from the fifth volution onward and on the later
whorls become extremely prominent, forming a conspicuous feature of the
ornamentation. Both ribs and varices are set at an angle with the verti-
cal axis of the shell, so that they appear to twist in passing from whorl to
whorl. On the tenth volution of those present the two lower spirals
again become more prominent than the sub-sutural row, giving an oblique-
angled outline to the volution, which has vertical sides and a row of strong
nodes on the shoulder. Rather coarse intercalated spirals cover all the
surface between the rows of nodes. Just above the suture a row of fine
nodes is partially concealed by the succeeding whorl. On the body volu-
tion the shoulder is nearly obsolete, and there are six rows of nodes, of
which the two upper are the strongest. A very strong varix is present
on the side opposite the outer lip.

The aperture is elongate oval, with a narrow, thick callus and well-de-
veloped posterior tooth. The outer lip in some individuals is extremely
thick, and the aperture in these specimens is somewhat constricted by the
addition of material to the inner margin. Other specimens do not show
such thickening of the lip. The siphonal canal is short and slightly re-
flexed at the margin. At an earlier stage of growth the canal was bent
toward the left, but the animal has abandoned this position and continued
the canal in a downward direction, the earlier growth being left as a
curious knob on the outside of the tube.

HorIZON AND LOCALITY: Miocenic. Martillac near Bordeaux.
No. 20141, Columbia University collection.

REMARKS: This species bears a striking resemblance to the Florida
species, C. glaphyrea, in the closely set ribs, the number of the spirals
and the form of the aperture; but it differs in being a more closely coiled
form and in having numerous very strong varices.

This species has been made the type of a new genus, Chondrocerithium,
the distinguishing characteristics being the presence of a columnellar pli-
cation and slight differences in the aperture. The development of the
species shows its close relationship to Cerithiwm, and the aperture does not
differ in any essential respect from many species of that genus. A faint

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 45

trace of columnellar plication was found on only one of the seven speci-
mens studied, and this barely distinguishable feature seems insufficient
ground for the establishment of a new genus.

Cerithium calculosum, mut. globulus n. mut.

Like Cerithium glaphyrea, C. calculosum has a variety which differs
from the type in having finely nodose spirals intercalated between the
stronger ones and in having the row of fine nodes just above the suture
fully exposed rather than covered by the next whorl, as in the case of
the original species.

HorRIZON AND LOCALITY: Miocenic. Martillac near Bordeaux.
No. 20142, Columbia University collection.

Cerithium chipolanum Dal

1892. Cerithium chipolanum DAL, Trans. Wagner Free Institute of Sci., Phila.,
WO, jos. 2h Bisby ole Zee sakes Ye

MEASUREMENTS (Dall): Length, 10 mm.; greatest diameter, 4.5 mm.

A specimen of this species has not been obtainable, but a good figure
and description make possible the determination of its relationship with
a fair degree of probability. The author of the species describes four
spirals on each volution, and the figure shows that in the young shell two
of these are more prominent than the others, forming the oblique-angled
outline of the whorl characteristic of the Cerithiwm tuberosum group.
Later in the growth of the shell the lower of the two strong spirals be-
comes weaker, giving a sharply angled outline to the whorl. On the
body whorl two of the spirals on the shoulder increase in size, so that the
ornamentation of this volution consists of a shoulder with two strong
spirals on its slope and two below the shoulder angle.

The aperture is of the type usual in this group, with a well-developed
posterior tooth and short, widely open anterior canal.

Horizon AND LOCALITY: Older Miocenic of the Chipola beds, northwest
Florida.

Remarks: Dall states that C. chipolanum is not closely related to any
of his preceding species, which would include @. callisoma and C. gla-
phyrea, but he does not say in what respect the divergence is expressed,
unless the high development of varices mentioned is considred such a dif-
ference. Varices are, however, characteristic features of Cerithiwm sens.
str. This little species is more closely coiled than the Pliocenic C. callt-

46 ANNALS NEW YORK ACADEMY OF SCIENCES

soma or the recent C.tuberosum and resembles in that respect C.adansoni.
It may be the American representative of the Miocenic ancestor of the
latter species rather than a member of the direct line toward C. tuber-
osum.

2. Vulgocerithium

Specimens of Vulgocerithium vulgatum are reported by Hornes and
Partsch [1856, p. 388] from the Miocenic of Italy and the Vienna Basin.
The species seems to persist through the Miocenic and Pliocenic to recent
time.

Hornes and Partsch describe several other species which are evidently
closely related to V. vulgatum.

Vulgocerithium minutum Serres

This species is recorded by Hornes and Partsch [1856, p. 390] from
the Miocenic of the Vienna Basin. Specimens have been obtained from
the upper Oligocenic of Saucats, and the species is described with others
from that horizon. The Oligocenic specimens differ from the figures of
Hornes and Partsch [1856, plate 41, figs. 8, 9] in their smaller size and
the less prominent nodes of the median row.

Vulgocerithium zelebori Hornes and Partsch

1856. Cerithium zelebori HOrNES and PArtscH, Abhand. der k. k. geol. Reich-
sanstalt, III, 391, pl. 41, fig. 10.

This species seems to be closely related to V. minutum, differing in the
more rounded nodes, less continuous ribs and the greater distinctness of
the sub-sutural row of nodes. The young stages are not described in
detail, and the figures are not sufficiently enlarged to show them clearly,
but the general form, aperture and surface ornamentation are so similar
to those of V. vulgatum that they may be referred to the same group with
a high degree of probability.

Vulgocerithium doliolum Brocchi

1814. Cerithium doliolum Broccuti, Conchiologia fossile subappen., II, 442, pl.
9, fig. 10.

‘1856. Cerithium doliolum HoOrNES and PartscH, Abhand. der k. k. geol. Reich-
sanstalt, III, 392, pl. 41, fig. 11.

Hornes and Partsch record this species from the Miocenic of Italy and
the Vienna Basin. It has a somewhat shorter spire than most species of
Vulgocerithiwm, but it is similar to shells of this group in the character

WOOD, PHYLOGENY OF CERTAIN CERITHIUDZ 4”

of the ornamentation and the form of the aperture. The nodes of the
sub-sutural row and of the first primary spiral have a somewhat more
rounded form than most species of the genus, and rows of fine nodes are
intercalated between them.

A variety represented by fig. 12a, b, has the high spire characteristic
of the typical Vulgocerithium.

Vulgocerithium rubiginosum Eichwald

1830. Cerithium rubiginosum HicHwaup, Naturh. Skizze von Lithauen, Vol-
hynien u. s. w., p. 224.

1856. Cerithium rubiginosum Hornes and Partscu, Abhand. der k. k. geol.
Reichsanstalt, III, 396, pl. 41, figs. 16, 18.

So far as can be learned from the descriptions and figures, this little
species has all the characteristics of Vulgocerithium. It differs from the
last species in the absence of the intercalated rows of fine beading, and
the nodes are somewhat more prominent. The species is recorded by
Hornes and Partsch from the Miocenic of the Vienna Basin.

E. OLIGOCENIC AND EOCENIC SPECIES
1. Cerithium

The relationship between the Oligocenic and Kocenie species is so close
that it has been thought best to consider them together, taking up the
forms in the phylogenetic rather than the stratigraphic order.

Cerithium zquispirale sp. nov.
Plate 11, fig. 5; plate v, figs. 3, 4; plate v1, fig. 3.

MEASUREMENTS (last five volutions): Length, 23 mm.; greatest diameter,
10.1 mm.; apical angle, 33.5°, changing to 26.8° on the last three volutions;
sutural angle, 85°.

The general form of this shell is high and narrow, with moderately
embracing whorls and but slightly impressed sutures. The apex of the
shell is broken away, and the earliest volution preserved has a diameter of
4 mm. and height of 1.4 mm. On this volution, two spirals are stronger
than the others and are equal in strength. A third primary spiral at the
base of the whorl is partly covered by the succeeding volution. Between
the stronger primary spirals a secondary and two tertiary ones appear,
and one primary, with four secondary spirals, is above the shoulder
angle. This volution bears eleven strong, rounded ribs, which are well

48 ANNALS NEW YORK ACADEMY OF SCIENCES

developed from suture to suture. The first, fourth and eighth ribs are
much stronger than the others, forming varices. On the later volutions,
these varices appear at irregular and less frequent intervals, having in
the adult from five to ten ribs between the varices. On the succeeding
volutions more spirals appear, until those of the fifth order may be
counted. These are very fine, but still preserve their rounded character,
and several of equal strength are crowded between the coarser spirals.
The strong shoulder and the two equal primary spirals persist until the
body volution is reached. On the latter volution the primary spiral on
the shoulder becomes as strong as the primary ones below it, and the
shoulder, which is still present on the preceding volution, disappears. The
body volution bears below the three primary spirals already mentioned
three more strong spirals, with finer ones between them. Here, too, the
ribs become weaker, the spirals stronger, and at the crossing of the two
there is a tendency to form nodes, though the development does not go
far enough to form actual nodes. On the later portion of the body whorl
the sub-sutural spiral becomes as strong as the two primary ones.

The aperture of the shell is oval, with short, reflexed anterior canal. A
well-defined posterior canal is also present, the inner margin of which is
bounded by a ridge, but not a distinct tooth, such as appears in Cerithiwm
tuberosum. ‘The inner lip is covered by a narrow callus, and the outer
lip is slightly flaring and notched to correspond with the strong spirals
of the exterior surface.

HORIZON AND LOCALITY: The precise horizon of this species is not known, but
it was found in a collection of unidentified shells from the Eocenic of the
Paris Basin.

No. 10328, Columbia University collection.

REMARKS: Cerithium e@quispirale has a close resemblance in form and
in the features of the aperture to C. lamellosum, but it differs from that
species in the character of the spirals, which are strongly developed and
have a rounded form instead of appearing like imbricating lamelle, as in
the latter species. (C./amellosum also differs in the loss of its secondary
spirals on the adult whorls.

C. equispirale has the two strong spirals and the numerous spirals of
higher order characteristic of C. tuberosum, and it retains these features
throughout life. The body volution has especially strong spirals on its
lower slope, and the lower part of the outer lip grows a little more rapidly
than the upper part. The persistence and development of this tendency
would in time produce a strong projection of the lower spirals like that
seen on the aperture of C. tuberosum. At the same time the prominent

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 49

sub-sutural spiral on the later part of the body volution of C. @quispirale
suggests the Vulgocerithium group. The species may well be a type from
which the C. tuberosum group arose, but Vulgocerithium probably arose
from the ancestor of C. wquispirale, C. cornuelianum.

The young stages of C. equispirale are unfortunately missing, but the
adult shell is so similar in general character to C. lamellosum that the
young stages may also have been similar, although this is not certain to
be true, for similarity in adults does not necessarily mean similarity in
the young.

Cerithium lamellosum Brugwuiére
Plate 111, figs. 7, 8; plate Iv, fig. 8; plate v, figs. 7, 8; plate v1, fig. 6.

1792. Cerithium lamellosum Brueutere, Encycl. Méthod., p. 488.

1824. Cerithiwm lamellosum DESHAYES, Desc. des coquilles foss. des environs
de Paris, p. 370, pl. 64, figs. 8. 9.

1866. Cerithiwm lamellosum DrsHayrs, Desc. des animaux sans vert. décou-
verts dans le bassin de Paris, III, 159.

1906. Ptychocerithium lamellosum CossMANN, Essais de Paléoconch. Comp.,
VII, 81.

MEASUREMENTS: Length, 48.4 mm.; greatest diameter, 13.8 mm.; apical
angle, 29°, changing to 18° on the eleventh volution; sutural angle, 84°.

The volutions of this species embrace but slightly, producing a long,
slender shell. The general outline of the whorls is gently rounded, with
slightly impressed sutures.

The early stages of growth are best seen on a young individual of nine
volutions. The beginning of the protoconch of this specimen is not
preserved, but it seems to have comprised about one and one-half volu-
tions. Beyond this a spiral appears at about the middle of the whorl,
the portions above and below the spiral becoming flattened until a dis-
tinct shoulder is produced. On the second volution beyond the proto-
conch the spiral has become elevated at regular intervals to form faint
nodes, and on the third volution another spiral appears below the first,
while the nodes are elongated into faint ribs. The second spiral soon
becomes as strong as the first, and the two form a slight projection
around the median portion of the whorl. The two equal spirals remain
stronger than the others throughout the life of the animal, but the shoul-
der is never a conspicuous feature of the ornamentation. On the suc-
ceeding volution, the fourth beyond the protoconch, there is a faint con-
striction of the shell below the suture, which, with the suture itself, out-
lines an indistinct spiral. The two volutions which follow are like the

50 ANNALS NEW YORK ACADEMY OF SCIENCES

fourth, with a gradual strengthening of the characters already intro-
duced. On the seventh volution faint secondary spirals are intercalated
between the first two and on the shoulder above the first spiral. The
ribs are well defined and extend from suture to suture, about one on each
volution being enlarged to form a varix, a feature which persists on all
the later whorls. The ninth volution differs only in having an addi-
tional faint spiral just below the sutural one.

An adult individual shows twelve volutions, from which, as shown by
comparison with the young, about four volutions in addition to the
protoconch have been broken away. On the eleventh volution of this
specimen the spirals are five in number, with ribs extending from suture
to suture, and separated by interspaces slightly wider than themselves.
Although the surface is much dissolved, faint traces of secondary and
tertiary spirals may be seen. The strength of all the spirals varies con-
siderably, not only with the condition of preservation, but in different
individuals similarly preserved. Some individuals show the secondary
and tertiary spirals distinctly, while they are hardly visible on others.
The spirals of this species, especially on the later volutions, have their
upper edge projecting sharply and their lower edge merging into the sur-
face of the shell, so that the whorls appear to be made up of overlapping
lamelle with their edges turned upward. On the later part of the body
volution the spiral just below the suture is broken up into nodes, and the
three spirals below the central band become extremely strong.

The aperture is oval, with a deep anterior canal and a well-defined
posterior canal. The callus of the inner lip is narrow but comparatively
thick. The outer lip is folded into a series of prominent lobes, which
correspond in position with the spirals on the outside of the shell.

HorIzoN AND LOCALITIES: Calcaire Grossier (Upper Eocenic). Chaussy and
Grignon, Paris Basin.
No. 20148, Columbia University collection.

Remarks: This species begins its life history in a much simpler man-
ner than any of the species thus far described, and it is not until the
sixth volution that it fully acquires the shoulder, which in recent accel-
erated forms begins immediately after the protoconch. The primitive
stages preceding the formation of ribs, and with one volution only, have
been crowded out of the ontogeny by acceleration in such forms as Ceri-
thium adansoni and C. tuberosum.

Cerithium lamellosum does not continue its development in the direc-
tion of C. tuberosum, for, after having acquired intercalated spirals of
high orders, it nearly or quite loses them on the adolescent and adult

WOOD, PHYLOGENY OF CERTAIN CERITHUDX 51

whorls, and the form of the spirals changes to the imbricated type de-
scribed above. On account of this divergence expressed in the adult
shell, C. lamelloswm may be considered a lateral branch from the line
developing in the direction of C. tuberosum. No descendants of C.
lamellosum have been found in the material studied, and it may have
died out at the end of the Eocenic without giving rise to later species.

The young of C. lamelloswm gives a clue to the kind of development
which preceded the stage with ribs and two strong spirals, and it is to be
expected that from such primitive conditions development would take
place in several different directions. This we find to be the case, as illus-
trated by several of the following species.

M. Cossmann refers this species to Ptychocerithium on account of the
narrow opening of the canal and the strong varix opposite the outer lip.
He considers it as closely related to Vulgocerithium, but from the devel-
opment of the early stages it seems to be more closely related to Cerithium
than to either of these.

Cerithium inabsolutum Deshayes ?

1866. Cerithium inabsolutwn DESHAYES, Desc. des animaux sans vert. décou-
verts dans le bassin de Paris, III, 170, pl. 74, fig. 28.
1906. Ptychocerithium inabsolutum CoSSMANN, p. 80.

MEASUREMENTS (young individual): Length, 10 mm.; greatest diameter, 4
mm.; apical angle, 23.5°; sutural angle, 85°.

Two very small individuals probably represent the young of C. inabso-
lutum, but are referred to that species with doubt, since no adult is avail-
able for comparison with them.

A part of the protoconch is present on one specimen and, so far. as can
be determined, is like that of C. adansoni. The first complete volution
is .8 mm. in diameter and bears two continuous spirals, one of which
appears slightly before the other. This type of ornamentation continues
for six volutions, but on the seventh ribs are developed, fine spirals appear
on the shoulder and a spiral is intercalated between the two primary
spirals. Strong varices to the number of one or two to the volution are
developed on the remaining whorls. On the eighth volution a constric-
tion below the suture defines a sub-sutural band which is raised into
nodes where crossed by: the ribs, and numerous spirals of higher order
are introduced. The shell comprises eleven volutions, and the two
strong, equal spirals characteristic of Cerithiwm remain undiminished in
strength on the last volution present. The lower slope of the body volu-
tion bears two strong spirals with three finer ones below them.

52 ANNALS NEW YORK ACADEMY OF SCIENCES

The aperture is oval, with a long columella and poorly formed siphonal
canal. No callus is present on the inner lip, and the outer lip is too
much broken to determine its character. '

HORIZON AND LOCALITY: Caleaire grossier. Grignon, Paris Basin.
No. 2564, Museum of Comparative Zodlogy collection.

Remarks: The absence of a callus on the inner lip and the poorly
formed siphonal canal accompanying a surface ornamentation character-
istic of young Cerithium seem to indicate that these specimens are young
individuals. They are referred to C. inabsolutum on account of the elou-
gation of the lower part of the aperture and the character of the orna-
mentation, which seems to correspond with that described for the species.
Whether or not the specific identification is correct, they belong undoubt-
edly to the genus Cerithium sens. str.

Cerithium calcitrapoides Lamarck

1804. Cerithium calcitrapoides LAMARCK, Ann. du Mus. Nat. d’hist. naturelle
de Paris, III, 274.

1824. Cerithium calcitrapoides DrSHAYES, Dese. des coquilles foss. des envi-
rons de Paris, 347, pl. 46, figs. 18, 19, 23.

1906. Batillaria calcitrapoides CoSSMANN, Essais de Paléoconch. Comp., VII,
134.

MEASUREMENTS: Length, 50 mm.; greatest diameter, 18 mm.; apical angle,
25°; sutural angle, 87°.

The youngest volution studied has an ornamentation of one spiral
only. On the next volution a second spiral appears above the first, and
on the fourth volution of those preserved, the two spirals are crossed by
ribs, but it is not until the fifth volution that the two spirals become
equal in strength. At this stage the shell has the shoulder characteristic
of Cerithium, with two equal spirals crossed by ribs. On the seventh
volution a spiral is intercalated between the two primary spirals, and fine
ones appear also on the shoulder and on the lower slope of the whorl. On
the ninth volution the lower primary spiral has become weaker than the
upper, a tendency which increases until, on the twelfth and later volu-
tions, the lower primary spiral is reduced to the size of the secondary
ones, and the upper spiral forms the projecting margin of a sharply
angled volution.

The aperture is elongate oval, with a thick callus on the inner lip and
short, widely open canal. The outer lip is slightly crenulated.

HorIzoN AND LOCALITIES: Calcaire grossier, Sables Moyens. Grignon and

many other localities in the Paris Basin.
No. 3377, American Museum collection.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 53

REMARKS: This species resembles C. equispirale in the young but
diverges from the type of development illustrated by that species in the
adult. It may be considered a lateral branch from the main line of evo-
lution of Cerithium.

Cerithium bicarinatum Deshayes
Plate 11, fig. 8.

1824. Cerithium bicarinatum DesHayeEs, Desc. des coquilles foss. des environs
de Paris, p. 356, pl. 53, figs. 14, 15. .

MEASUREMENTS: Length, 24 mm.; greatest diameter, 9.5 mm.; apical angle,
20°; sutural angle, 85.5°.

The youngest volution preserved on the specimen described is .7 mm.
in diameter and is ornamented by two spirals, the lower of which is the
stronger. Ribs are absent at this stage. The two succeeding volutions
are like the first, except that the upper spiral becomes equal to the lower
in strength. On the fourth of the volutions preserved ribs appear, and
on the fifth a faint constriction below the suture defines a slight sub-
sutural band, which, however, lasts for only two volutions and is not seen
on the adolescent and adult stages. The specimen thus far described is
a young individual preserving only eight volutions, but the same type of
ornamentation persists on full-grown specimens, the adult ornamentation
being simply two strong spirals with a long shoulder slope, a concave
surface between the two spirals and a short lower slope. The body volu-
tion has two spirals below the primary ones.

The aperture is nearly circular, with a short siphonal canal so widely
open that its cross-section does not represent a curve of more than 180°.
The callus of the inner lip is narrow and has a slight projection near the
posterior end, although a distinct tooth is not formed. The outer lip is
broken on all the specimens obtainable, but it was evidently thin and,
according to the figure of Deshayes, was not crenulated.

HorRIZON AND LOCALITIES: Sables Moyens (Upper Eocenic). Acy-en-Multien
and many other localities in the Paris Basin.
No. 20144, Columbia University collection.

Remarks: The adult of this species corresponds in essential character-
istics with the fifth volution of Cerithium lamellosum and with the sec-
ond of C. adansoni, and although occurring at a higher horizon than
C. lamellosum, it illustrates a more primitive type of development. It
represents the persistence of a type of shell which was probably devel-

.

54 ANNALS NEW YORK ACADEMY OF SCIENCES

oped as far back in geologic time as the Triassic, since we have in Jurassic
time a shell with rounded volutions and an ornament of three simple
spirals, which was probably developed from a two-spiraled form just as
the mutation trispirale, described below, arose from the type species by
the development of another spiral on the shoulder.

Cerithium bicarinatum mut. trispirale n. mut.
Plate 1, fig. 7.

1824. Cerithium bicarinatim DESHAYES, Desc. des coquilles foss. des environs
de Paris, p. 356, pl. 53, fig. 6.
1866. Cerithium bicarinatum DESHAYES, Desc. des anim. sans vert. découverts
dans le bassin de Paris, p. 180.
MEASUREMENTS: Length, 25 mm.; greatest diameter, 10.2 mm.; apical angle,
25°; sutural angle, 85°.

The development of the variety is precisely the same as that of the
type species to the seventh volution, on which a faint third spiral is in-
troduced above the two primary ones. This spiral grows rapidly until
it equals in strength the lower primary spiral. The median spiral is
slightly stronger than the others, so that the outline of the volution
would be a regular curve if represented by a line touching the edges of
the spirals. This type of ornamentation persists throughout the re-
mainder of shell growth. The body volution has two strong spirals and
three or more fine ones below the three primary spirals. The aperture is
like that of the type species.

HorIZON AND LOCALITIES: Sables Moyens (Upper Hocenic). Acy-en-Multien
and other localities in the Paris Basin.
No. 20145, Columbia University collection.

RemMarKS: This mutation differs from the type species only in the
presence of a third spiral, which becomes strong enough to change the
outline of the volution. ‘There is a perfect gradation between the species
and its mutation, since specimens of the former are found in which the
third spiral is barely distinguishable as a faint elevation on the adult
whorls,-and others in which this feature appears earlier and earlier in
the ontogeny until the typical form of the mutation is developed. The
mutation represents merely the next step in the evolution of this group.

Cerithium retardatum sp. nov.
Plate 11, fig. 6.

MEASUREMENTS: Length, 27.2 mm.; greatest diameter, 1.5 mm.; apical angle,
24°; sutural angle, 86°.

ii lees

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 55

The early stages of this species are described from a young individual
of ten volutions. The protoconch of this specimen is missing, but the
youngest volution preserved is .6 mm. in diameter and is probably the
first volution beyond the protoconch. It is ornamented by a single
spiral only, and no ribs are present. Another spiral is added above the
first on the next volution, and on the third volution of those preserved,
the two spirals become of nearly equal strength. Ribs first appear on
the fourth volution and on the fifth, a fine third spiral appears above the
two primaries. The three spirals are well developed on the seventh volu-
tion, and on the eighth the first intercalated spiral is introduced between
the two lower primary ones. Another intercalated spiral soon appears
between the two upper primary spirals, and the adult whorls have one
spiral intercalated between each pair of primaries, with two fine spirals
above and two below the three primary spirals. The body volution has
two strong and six very fine, closely set spirals on its lower slope.

The aperture is similar to that of C. bicarinatum, being nearly circular,
with shallow anterior canal. The callus of the inner lip is wider and
the posterior ridge better developed than on C. bicarinatum. The outer
lip is somewhat broken, but the lines of growth indicate that its lower
margin grew more rapidly than the upper one.

HoRIZON AND LOCALITIES: Sables Moyens (Upper Hocenic). Le Guépelle, Acy-

en-Multien, Paris Basin.
No. 20146, Columbia University collection.

REMARKS: Cerithium retardatum represents a step in advance of U.
bicarinatum mut. trispirale in the development of intercalated spirals.
The three forms, C. bicarinatum, its mutation, trispirale, and C. retarda-
tum, constitute a direct series in evolution. C. bicarinatum develops
ribs and two equal primary spirals only. The mutation trispirale car-
ries the development farther in the growth of a third primary spiral, and
C. retardatum advances still farther in the introduction of intercalated
spirals.

C. retardatum illustrates the law of recapitulation, for its fifth volu-
tion is like the adult of C. bicarinatum, and its seventh volution repre-
sents the adult of the mutation trispirale. At the same time the law of
acceleration is illustrated by this shell, since the evolution represented by
the entire life history of both C. bicarinatum and C. bicarinatum mut.
trispirale is passed over in the first seven volutions of C. retardatum.
But while C. retardatum is accelerated as compared with C. bicarinatum,
it is retarded as compared with C. wquispirale and other shells occurring
in the Upper Eocenic. It may be compared with the Upper Cretacic
C. albense in the main line of evolution of the C. tuberosum group.

56 ANNALS NEW YORK ACADEMY OF SCIENCES

Cerithium sp. undt.

MEASUREMENTS: Length, 13.5 mm.; greatest diameter, 5.8 mm.; apical angle,
35°, changing to 26° on the last three volutions; sutural angle, 83.2°.

Two small specimens of nine volutions each are the only representa-
tives of this species in the collections studied. They are probably young
individuals, but it is impossible to identify young shells from the figures
and descriptions as usually written.

The youngest volution preserved is .4 mm. in diameter and has one
spiral only. The next volution is too much worn to show the ornamenta-
tion, but the third volution has two spirals crossed by ribs. The two
spirals become of equal strength and, with the ribs, remain the only orna-
mentation until the sixth volution, when a fine spiral is introduced below
the lower spiral. On the next volution a spiral is intercalated between
the two primary ones, and on the eighth volution a fine spiral appears on
the shoulder. The body volution retains the characteristic two strong
spirals and has two fine spirals on the shoulder, with one intercalated be-
tween and one below the two primary spirals. The lower slope of the
body volution has two strong spirals and several finer ones below the
primary spirals. Spirals of the third order also appear on this lower
slope.

The aperture is circular, with a shallow anterior canal. The callus of
the inner lip is comparatively wide and has a distinct ridge near its pos-
terior end. The outer lip is thin and not crenulated on the young shell.

HorIzoN AND LOCALITY: Hocenic, Paris Basin. Precise horizon and locality
unknown.
No. 20163, Columbia University collection.

Remarks: This little shell is ike C. bicarinatum to the sixth volution,
after which it develops in a direction different from that of the two de-
scendants of C. bicarinatum already described, namely, C. bicarinatum
mut. trispirale and C. retardatum. This divergence is expressed in the
acquisition of a third spiral on the lower slope of the whorl, instead of
on the shoulder, as in the line of evolution just described. The spirals
of the shoulder slope are introduced later, but always remain fine, and
the shoulder persists to the last volution present on these forms, while it
is lost on C. bicarinatum mut. trispirale. This species may be consid-
ered a descendant of C. bicarinatum, but it represents a different path of
evolution from that, including C. retardatum.

WOOD, PHYLOGENY OF CERTAIN CERITHUDA 57
2. Vicinocerithium
. Vicinocerithium parallelum gen. et sp. nov.
Plate vii, figs. 4, 5; plate vii, figs. 4, 5; plate rx, figs. 3, 4.

MEASUREMENTS: Length, 29 mm.; greatest diameter, 12 mm.; apical angle,
80.5°; sutural angle, 81.5°.

The protoconch of this species is not preserved. The youngest volu-
tion present bears three spirals, the lowest of which is the most promi-
nent, and is separated by a wide interspace from the two upper spirals.
On the next volution ribs appear, and the median spiral becomes stronger
than the upper, but not quite so prominent as the lowest spiral. A slight
ridge below the suture forms a fourth ill-defined spiral. On the third
volution present the two lower spirals are equal in strength, and a fine
spiral is intercalated between them. The third spiral has also become
stronger, so that the outline of the volution is a regular curve. Two ad-
ditional fine spirals appear just below the suture. The fourth and fifth
volutions are essentially like the third, with an increase in the number of
fine spirals. On the sixth volution the median primary spiral becomes
stronger than the other two, and this tendency increases until, on the
adult whorls, this spiral forms the margin of a sharply angled volution,
with numerous fine spirals on the shoulder and the lower slope of the
whorl. The uppermost primary spiral is reduced to the rank of a sec-
ondary spiral, and the lowest primary spiral, originally the strongest on
the shell, is much reduced in relative size, though still stronger than the
secondary spirals. This and another strong spiral just above the suture are
crenulated, showing a tendency toward the formation of nodes, which on
the latest portion of the body volution are fairly well developed. A third
nodose spiral is present below those just described, and fine spirals are
intercalated between all coarser ones on the lower slope of the body
volution.

The aperture is nearly circular and the anterior canal is rather long
and widely open. The outer lip is thin and the inner lip is covered by a
strong callus.

HorIzoN AND LOCALITY: Sables Moyens. Le Guépelle, Paris Basin.
No. 20156, Columbia University collection.

REMARKS: This species has been considered identical with Cerithium
(Vicinocerithium) bouet DesH., and if the adult characters alone are
considered, they are hardly distinguishable, the only difference being that
the present species has a somewhat higher spire and the shoulder is far-

58 ANNALS NEW YORK ACADEMY OF SCIENCES

ther from the horizontal. The development of the two shells is quite
different, and for this reason they should rank as at least distinct species.
By comparing figs. 4, 5 on plate vi1, 4, 5 on plate vii1, 3, 4 on plate 1x
with figs. 6 on plate vi, 6 on plate vii1, 5, 6 on plate rx, it will be seen
that V. parallelum acquires its sharp shoulder by developing its median
primary spiral and retaining the lowest primary spiral in a subordinate
position, while V. bowei develops its uppermost primary spiral to form
the shoulder angle and the median spiral is reduced to the rank of a
secondary spiral, and is finally indistinguishable from them.

The development of V. parallelum and V. bouei differs so widely from
that of Cerithiwm that they should be referred to a distinct genus, as is
here done. A full diagnosis of the genus awaits a more extended study
of related species which should be included in the same genus. The two
species are described here to illustrate the case of parallelism mentioned
in the introduction.

Vicinocerithium bouei (Deshayes)
Plate vit, fig. 6; plate vim, fig. 6; plate rx, figs. 5, 6.

1824. Cerithium bouei DESHAYES, Desc. des coquilles foss. des environs de
Paris, II, 347, pl. 52, figs. 9-11.
1906. Batillaria bowei CossMANN, Hssais de Paléoconch. Comp., VII, 134.

MEASUREMENTS: Length, 22 mm.; greatest diameter, 9.5 mm.; apical angle,
32°; sutural angle, 81.5°.

A portion of the protoconch is preserved on one specimen. It is about
.4 mm. in diameter and apparently has the form of the typical Cerithiwm
protoconch. The next volution beyond the protoconch has apparently
but one primary spiral, forming a shoulder angle just above the suture.
The third volution has more fine spirals on the shoulder, and both ribs
and intercalated spirals appear for the first time on the fifth volution.
On the sixth volution two of the primary spirals above the spiral of the
shoulder angle become stronger, until on the succeeding volution all three
are of equal strength, making the outline of the volution an obtuse angle
with sloping upper surface and vertical sides. On the next two volu-
tions the uppermost of the three primary spirals becomes stronger, until
it forms the margin of an exceedingly sharp shoulder angle. Later the
median spiral becomes reduced to the size of a secondary spiral, the lowest
primary spiral becomes irregularly undulating, and another undulating
spiral of somewhat less strength is developed just above the suture.
These changes produce in the adult stage a volution that is almost indis-
tinguishable from that of V. parallelum.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 59

The aperture of this species is like that of V. parallelum, except that
the canal is somewhat shorter.

HORIZON AND LOCALITIES: Sables Moyens. Le Guépelle and many localities
in the Paris Basin.
No. 20160, Columbia University collection.

Remarks: V. bouei is referred by M. Cossmann to the genus Batilla-
ria, but a comparison with the type of that genus, B. zonale, shows a wide
difference in development, the latter species resembling Cerithiwm in its
early stages. As will be seen by comparing fig. 6, plate vi1, with figs.
2, 3, 4, plate m1, V. bowei differs from Certthium from the protoconch
stage onward, and this difference entitles it to rank as a distinct genus, as
noted above.

3. Potamides

Genus Potamides Brongniart

1810. Potamida Bronentart, Ann. du Mus. Nat. d@’hist. naturelle, XV, 468.

1822. Potamides BRONGNIART, in Cuvier’s Recherches sur les ossemens fossiles,
II.

1906. Potamides CoSSMANN, Essais de Paléoconch. Comp., VII, 103.

Genotype Potamides lamarcki BRONGNIART.

The genus Potamides is distinguished from Cerithiwm mainly in the
slight development of the siphonal canal. In the type of the genus P.
lamarcki this canal is short, widely open, and with its anterior margin
slightly reflexed. This type of canal persists with little change from the
middle Eocenic to recent time.

The early stages of Potamides, as pointed out in connection with the
description of the genotype, are closely similar to those of typical Ceri-
thium, but after having developed the Cerithium-like outline of the volu-
tion with two equal spirals crossed by ribs, species of the genus continue
to emphasize the formation of nodes as their most characteristic surface
feature, instead of accenting the spirals, as in Cerithium. In this paper
only those species are included in the genus Potamides which have not
only an aperture similar to the genotype, but also have young stages in-
dicating a similar path of development.

Cerithium and Potamides are without doubt closely related genera,
and Potamides is the more primitive in structure. The aperture of the
young Potamides is almost destitute of canal, while the aperture of the
young Cerithium is like that of Potamides, and it is reasonable to suppose
that the order of evolution has been from forms without canal to those

60 ANNALS NEW YORK ACADEMY OF SCIENCES

with the slight canal of Potamides, and later to the well-developed canal
of Cerithium. Hence the ancestor from which both genera are derived
must have been more like Potamides than like Cerithium, although the
type of Potamides, P. lamarcki, and other species of the genus occur at
higher horizons than many well-developed species of Cerithium. They
represent the persistence of a primitive type of structure throughout a
long period of geologic time, while Cerithium, though descended from a
common ancestor, represents a more rapid evolution of highly specialized
forms.

Potamides lamarcki Brongmart

1810. Potamides lamarcki Bronentart, Ann. du Mus. Nat., d’hist. naturelle,
Nev. 4685) ply 22; ie:

1824. Cerithiwn microstoma DrEsHAYES, Desc. des coquilles foss. des environs
de Paris, II, 412, pl. 59, figs. 32-34.

1866. Cerithium lamarcki DresHAYES, Dese. des animaux sans vert. découverts
dans Je bassin de Paris, III, 177, pl. 80, figs. 25-28.

1906. Potamides lamarcki CoSSMANN, Essais de Paléoconch. Comp., VII, 103.

MEASUREMENTS: Length, 22.8 mm.; greatest diameter, 6.6 mm.; apical angle,
19°; sutural angle, 88.5°.

The protoconch of this species is beautifully preserved on a small indi-
vidual of seventeen volutions. The form is similar to that of Cerithium
adansoni, and the surface is smooth and shining. It comprises about
one and one-half volutions, after which two fine spirals of equal strength
appear and remain the only ornamentation of the shell for three volu-
tions. On the fifth volution the spirals are crossed by ribs, and for the
next four volutions the shell has the characteristic ornamentation of the
young Cerithium—that is, an angular outline formed by two equal spirals
crossed by ribs. On the ninth volution a third spiral is added just below
the suture, and all the spirals form nodes where crossed by the ribs. The
median row of nodes lags slightly behind the others, so that the ribs are
curved in crossing the volutions. The ornamentation of the adult con-
sists of three strong nodose spirals which are rectangular in cross-section
and a fine continuous spiral just above the suture. The ribs are faint
or obsolete in the adult, and the entire surface of the shell is covered by
extremely fine, closely set spirals, which are only visible with a strong
lens. Some specimens show gerontic characters in the thickening of the
shell and the loss of the nodes on the body volution. The lower slope of
this volution bears three spirals in addition to those already mentioned.

The aperture is nearly circular. The callus of the inner lip is thin
and.spread out broadly over the lower surface of the body volution, and

i et

: WOOD, PHYLOGENY OF CERTAIN CERITHIUDA 61

the outer lip is thin and strongly sinuous. The anterior canal is very
short, shallow and has a reflexed margin.

HORIZON AND LOCALITY: Oligocenic. Aurillac, Paris Basin.
No. 20158, Columbia University collection.

Remarks: This species follows the same path of evolution as Ceri-
thium adansoni for the first nine volutions, but is more retarded in the
development of ribs than that species. After the ninth volution the
shoulder is lost, and the species diverges from the Cerithium line of eyvo-
lution. The adult has flattened volutions and an ornamentation of rows
of nodes instead of the angular outline of the whorls and several orders
of spirals characteristic of Cerithiuwm.

As compared with Eocenic species of Cerithium—C. equispirale, for
example—Potamides lamarcki is more primitive in structure, having a
less well-developed canal and simpler type of ornamentation, and it rep-
resents, as noted in connection with the genus, the persistence of a primi-
tive form while more rapid evolution was taking place in related groups.

Potamides cordieri mut. typum n. mut.

1824. Cerithiwm cordieri var. a DESHAYES, Desc. des coquilles foss. des en-
virons de Paris, II, 338, pl. 52, fig. 8.

MEASUREMENTS: Length, 29.8 mm.; greatest diameter, 11.5 mm.; apical angle,
25°; sutural angle, 84.5°.

The youngest volution present is .6 mm. in diameter and is ornamented
by ribs and two equal spirals. The same ornamentation continues for
four volutions, and on the fifth a nodose spiral appears just below the
suture. This spiral increases in strength and becomes more distinctly
nodose until, on the eleventh of the volutions preserved, it is as strong
as the two nodose spirals below it. At this stage the general outline of
the volution is straight and parallel with the slope of the spire, and its
surface is ornamented by three equal rows of nodes without ribs. The
same ornamentation is continued until the fourteenth volution, when the
loose coiling reveals a continuous spiral just above the suture. On the
fifteenth volution present a fine, slightly nodose spiral appears between
the two upper rows of nodes. The same kind of ornamentation contin-
ues throughout the remaining whorls. The body volution has three rows
of strong nodes—one fine intercalated row and two strong continuous
spirals below the ornamentation of nodes. On the later part of this volu-
tion the growth lines are crowded, the shell somewhat thickened and the
nodes indistinct or obsolete.

62 ANNALS NEW YORK ACADEMY OF SCIENCES
The aperture is quadrangular, with short, widely open siphonal canal.
The callus of the inner lip is thick and broad. The outer lip is strongly
sinuous.
HorIzoN AND LOCALITIES: Sables Moyens. La Chapelle, Le Guépelle and

other localities in the Paris Basin.
No. 20153, Columbia University collection.

ReMArkKs: Were it not for the old-age features present on the later
part of the body whorl, this variety might be taken for the young of the
type species mentioned below, but the shell appears in all ways like a full-
grown individual, with a length only about half that of P. cordiert.

The development of this form is closely similar to that of P. lamarcht,
and the adult differs but slightly in general appearance. It is, however,
larger, has a wider apical angle and lacks the extremely fine spirals cov-
ering the surface between the nodes as in P. lamarckt.

Potamides cordieri Deshayes

1824. Cerithiwm cordieri DESHAYES, Desc. des coquilles foss. des environs de
Paris, II, 338, pl. 52, figs. 14, 15.

1866. Cerithium cordieri DESHAYES, Desc. des animaux sans vert. découverts
dans le bassin de Paris, III, 137.

1906. Ptychopotamides cordieri CossMANN, Essais de Paléoconch. Comp. VII,
108.

MEASUREMENTS: Length, 60 mm.; greatest diameter, 20 mm.; apical angle,
23.5°; sutural angle, 90°.

The only specimen of this species available for study is broken at the
apex, but enough remains to show that the development of this shell is
like that of the mutation typum and remains the same in all ways except
in the number of spirals on the last two or three volutions. P. cordiert
differs from its mutation only in its greater size and in the fact that
while P. cordieri mut. typum has only one row of fine nodes intercalated
between the coarser ones, the type species has a similar row intercalated
between the two lower and also below the lowest of the three rows of
strong nodes. The intercalation of fine nodes in the remaining inter-
spaces would naturally follow their introduction in one of them, so that
the adult P. cordieri constitutes the next step in this line of evolution
beyond that of P. cordiert mut. typum. For this reason it would have
been more appropriate to consider the mutation typum the type species;
but the name being already established for the larger specimens, it should
not be changed.

HorIzON AND LOCALITIES: Sables Moyens. La Chapelle and other localities
in the Paris Basin.
No. 20154, Columbia University collection.

WOOD, PHYLOGENY OF CERTAIN CERITHIDA 63

REMARKS: Potamides cordiert and its mutation are referred by M.
Cossmann to Ptychopotamides, a genus which is distinguished from
Potamides by the presence of a columellar plication, but such a plication
is certainly absent from all of the eleven specimens studied, and the
close similarity in development between this form and P. lamarcki has
led to the placing of the species in the genus Potamides.

Potamides involutum Lamarck

1804. Cerithium involutum LAMARCK, Ann. du Mus. Nat. d’hist. naturelle de
Paris, III, 348.

1824. Cerithium involutwum DESHAYES, Desc. des coquilles foss. des environs
de Paris, II, 328, pl. 41, figs. 10-18.

1906. Tympanotomus involutum CoSSMANN, Essais de Paléoconch. Comp., VII,
120.

MEASUREMENTS: Length, 30 mm.; greatest diameter, 10 mm.; apical angle,
25°; sutural angle, 87°.

The youngest volution seen on this species is .8 mm. in diameter. It
has at this stage ribs and two equal spirals. The same ornamentation
continues for three volutions, and on the fourth a third spiral is intro-
duced above the two already existing. This spiral increases gradually
in strength until, on the eighth volution, it is as strong as the two below
it. At this stage the shoulder has disappeared, and the surface is orna-
mented by three equal rows of nodes and a fine continuous spiral just
above the suture. On the later whorls, at a stage varying in different in-
dividuals, the nodes are lost, leaving the surface marked by continuous
spirals only. Still later the two lower spirals also disappear, leaving a
single spiral which forms the margin of a strong shoulder angle just
below the suture. The extent of this smoothing of the shell varies
greatly on different individuals, occupying three or more volutions, or the
spirals, and even the nodes, may persist nearly to the end of the body
volution. Specimens on which the smooth portion comprises several
volutions have also a narrower angle of slope for the sides in this portion
of the shell, indicating a flattening of the whorls parallel to the axis of
coiling. The enibracing of the whorls is greater than in the young por-
tion of the shell, and on some specimens also a distinct canal is formed
at the posterior margin of the aperture by this overlapping of a fold in
the outer lip upon the preceding whorl.

The aperture is closely similar to that of Potamides lamarcki. The
siphonal canal is short and widely open, the callus of the inner lip thick,
and the margin of the outer lip strongly sinuous.

Horizon AND LOCALITY: Caleaire grossier. Cuise-la-motte, Paris Basin.
No. 20155, Columbia University collection.

64. ANNALS NEW YORK ACADEMY OF SCIENCES

Remarks: The shells included under this name form a perfect grada-
tional series from forms in which the loss of nodes appears only on the
later part of the body volution to those in which both nodes and spirals
are absent, if we include the forms figured by Deshayes, from nearly the
whole surface. So perfect is the gradation in the collection studied that
hardly two individuals are alike, and each may be considered a mutation,
though for convenience they are described under one name.

The loss of ornamentation, the flattening of the whorls and the over-
lapping of the later whorls upon the earlier are all old-age features which
indicate a progressive gerontism and approaching extinction in the
branch of evolution which they represent.

The life history of this species is closely similar to that of P. cordiert
mut. typicum, down to the stage when gerontic features begin to appear.
It differs from that species in having a wider apical angle, but the two
species are doubtless closely related.

Potamides lapidum Lamarck

1804. Cerithiwm lapidwum Lamarck, Ann. du Mus. Nat. d’hist. naturelle de
Paris, III, 350.

1824. Cerithium lapidum DESHAYES, Desc. des coquilles foss. des environs de
Paris, II, 421, pl. 60, figs. 21-22.

1906. Potamides lapidwn CossMANN, EHEssais de Paléoconch. Comp., VII, 104,
pl. 10, figs. 6-7.

MEASUREMENTS: Length, 31 mm.; greatest diameter, 9.5 mm.; apical angle,
18.5°; sutural angle, 88°:

The youngest volution studied is .8 mm. in diameter, and there are
evidently several volutions missing above this. Its ornamentation con-
sists of two very fine, equal, continuous spirals. On the next volution
these spirals are crossed by very faintly developed, oblique ribs which are
present with varying strength and frequency on the succeeding ten volu-
tions. These ribs are never well developed, and on the adolescent and
adult whorls they give place altogether to crowded lines of growth. On
the later volutions the spirals also become indistinct, and the whorls have
a rounded outline, with a surface roughened by the crowded lines of
growth and faint traces of one or two spirals. On the young of some
specimens the lower of the two spirals is more prominent than the upper,
and the ribs in crossing give it a nodose appearance, but this ornamenta-
tion also disappears from the later whorls.

The aperture is circular, with a thickened callus on the inner lip, and
the margin of the outer lip is sinuous. The siphonal canal is shallow
and broad, with a strongly reflexed margin.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 65

HORIZON AND LOCALITIES: Caleaire grossier. La Frileuse and many other
localities in the Paris Basin.
No. 20157, Columbia University collection.

Remarks: The highest development of ornamentation on this shell
advances but little beyond the stage with two simple spirals represented
by the second to the fourth volutions of P. lamarcki, and the develop-
ment of the ribs is so feeble as to correspond with only the earlier part
of the fifth volution of that species. P. lapidwm is doubtless developed
from the same ancestor as P. lamarcki, but since in the adult it becomes
more smooth, instead of developing a higher degree of ornamentation in
the direction of P. lamarcki, it probably represents a lateral branch from
the main Potamides line of evolution.

4. Potamidopsis
Genus Potamidopsis Munier-Chalmas

1900. Potamidopsis MuNtER-CHALMAS, Congrés géol. Paris, V, Chideville. Liste
générale, p. 375.
1906. Potamidopsis CosSMANN, Wssais de Paléoconch. Comp., VII, 109.

Genotype Cerithium tricarinatum LAMAROK.

M. Cossmann distinguishes this genus from true Cerithiwm as follows:

Enfin Potanidopsis se distingue des vrais Cerithinew par son canal court,
par son labre non replié en travers du canal, et aussi par ses tours imbriqués.
La séparation—qu’a proposée Munier-Chalmas, dans de simples listes de fos-
siles publiées a V’occasion du Congrés de 1900, sans aucene diagnose—est done
a retenir.

The earliest stages in the development of the genotype show that this
shell is derived from the same stock as the true Cerithium, but it diverges
from the main line of evolution so strongly and at such an early stage
that it deserves to rank as a distinct genus. M. Cossmann describes
Potamidopsis as a sub-genus of Potamides, but the group is more closely
related to Cerithium than to Potamides; hence it should not rank as a
sub-genus of the latter. It is also too distantly related to Cerithiwm to
constitute a sub-genus of that group, and hence it is here ranked as an
independent genus. ‘'o the distinguishing characters enumerated by M.
Cossmann may be added the numerous volutions producing a very high
spire; the close embracing of the whorls; the general outline of the volu-
tions, not convex, but conforming to the slope of the spire; the high
development of nodes and the absence of ribs on all except the nepionic
volutions of the shell. The aperture also varies in its angular outline—

66 ANNALS NEW YORK ACADEMY OF SCIENCES

the broad and thick callus of the inner lip, with no trace of posterior
tooth, and the short, oblique siphonal canal. The outer lip is often
thickened, and its anterior portion grows more rapidly than the posterior
part, making the outline of the margin strongly sinuous.

Potamidopsis tricarinata Lamarck
Plate vil, figs. 7, 8; plate vu, figs. 7, 8; plate rx, figs. 7, 8.

1804. Cerithium tricarinatum LamMarcK, Ann. du Mus. Nat. d’hist. naturelle,
III, 272, No. 4.

1824. Cerithium tricarinatum DESHAYES, Desc. des coquilles foss. des environs
de Paris, Il, 325, pl. 51, figs. 1, 8.

1866. Cerithium tricarinatwm DESHAYES, Desc. des anim. sans vert. découverts
dans le bassin de Paris, III, p. 123.

1902. Potamides tricarinatum CossMANN, Catal. illust. des coquilles foss. de
l’Eoc. des environs de Paris, IV, p. 69.

1903. Tympanotomus tricarinatum CossMANN, Paleontologia Universalis, Cent.
Teplrod. ese dea

1906. Potamidopsis tricarinatus CoSSMANN, HEssais de Paléontol. Comp., VII,
109, pl. 11, figs. 5, 6.

MEASUREMENTS :*° Length, 45 mm.; greatest diameter, 17 mm.; apical angle,
20°; sutural angle, 87°.

The early stages of the species are described from a young individual
of fifteen volutions. The protoconch is missing, but the youngest volu-
tion preserved is probably the first beyond the protoconch, as it has a
diameter of only .8 mm. It has an ornamentation of two equal spirals
without ribs, and the same ornamentation persists on the next volution.
Ribs appear on the third volution, which:has an ornamentation exactly
similar to the adult of Cerithiwm bicarinatum. On the fourth volution
the lower spiral becomes stronger and the upper one weaker, a tendency
which increases on the next three volutions until, on the seventh and
eighth volutions, the upper spiral has entirely disappeared, and the orna-
mentation consists merely of a single strongly nodose spiral, forming a
projecting shoulder angle just above the suture. The ninth volution has
a sub-sutural spiral the nodes of which are connected with those of the
shoulder angle by well-developed ribs. This type of ornamentation per-
sists for seven volutions more, and on the fourteenth volution a fine
spiral is intercalated between the two already existing. Comparing this
young individual with an adult, it is found that the latter is more re-
tarded in the growth of this fine spiral than the former. It does not

5The specimen measured is the one which seems to correspond most closely with the
figures of the type given in the Paleontologia Universalis, centurla 1, plate 3, figs. 1, 2,

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 67

appear on the adult individual until the sixteenth volution, after which
it becomes stronger and soon breaks up into a row of fine nodes placed
half way between the two rows already formed. The ribs become discon-
tinuous, and the last seven whorls are ornamented by three rows of nodes,
of which the lowest forms a projecting shoulder angle just above the
suture, and the median row is very slightly finer than the upper one. On
the later part of the body whorl all the nodes become indistinct or obso-
lete, where the crowding of the growth lines and thickening of the shell
indicate old-age conditions.

The aperture is about equal in length and width and somewhat angular
in outline. The callus of the inner lip is very thick and broad, its pos-
terior part often spreading out for a considerable distance over the pos-
terior part of the body whorl. There is no trace of posterior tooth, as in
Cerithium sens. str. The outer lip is often greatly thickened, strongly
flaring at the margin, and it overlaps more or less upon the preceding
whorl. The thickening of the shell, the loss of ornamentation and the
encroaching of the later part of the body whorl upon the preceding whorl
are all old-age features which indicate that the species is approaching its
extinction.

HoRIzZON AND LOCALITIES: Calcaire grossier, Sable Moyens. Grignon and
many other localities in the Paris Basin.
No. 20122, Columbia University collection.

REMARKS: The young stages of this species furnish a clue to its devel-
opment from a form resembling Cerithium bicarinatum, since its devel-
opment for the first four volutions is closely parallel to the development
of that species, and the fourth volution (counting the protoconch as one)
is the counterpart of the adult C. bicarinatum. The species could not,
however, have been developed from C. bicarinatum itself, since it occurs
at an earlier horizon, but was probably developed from the pre-Jurassic
ancestor of C. bicarinatum mentioned in connection with that species—
the same ancestor which probably gave rise along a different path of
evolution to C. corallense and its descendants, C. wquispirale, C. tubero-
sum, etcetera.

Potamidopsis tricarinata has developed many mutations by the accentu-
ation or suppression of one or another of its surface features. Of these
mutations, Lamarck has described one and given it the designation “£8,”
and Deshayes has indicated five others by letters from “hb” to “f,” the
letter “a” being used for the type species. The mutations occur at the
same horizon and localities as the type, and, as might be expected, transi-
tional forms exist between all of them.

68 ANNALS NEW YORK ACADEMY OF SCIENCES

Potamidopsis tricarinata mut. baucis mut. nov.
1804. Cerithium tricarinatum var. B LAMARCK, Ann. du Mus. Nat. d’hist nat-
urelle; Paris, III, 272.
The author says of this species:

Dans la variété g, la caréne supérieur de chaque tour est un peu plus émi-
nente que celle du milieu.

The mutation is apparently more common than the type species, since
it is rare to find specimens in which the two upper rows of nodes are
equal. The upper row is slightly stronger, even in the type figured in
Paleontologia Universalis, but the varietal name may be retained for
those forms in which the difference is strongly developed.

No. 20121, Columbia University collection.

Potamidopsis tricarinata mut. brontes mut. nov.

1824, Cerithiwm tricarinatum var. b DrsHAyYES, Dese. des coquilles foss. des
environs de Paris, II, 325, pl. 51, fig. 2.

This mutation is distinguished by the strong carina which forms a
projecting shelf around the whorls and by the fine nodes of the two upper
spirals. The shells of this variety are usually larger than those of the
typical form.

No. 20123, Columbia University collection.

Potamidopsis tricarinata mut. cronus mut. nov.

1824. Cerithium tricarinatum var. @ DESHAYES, Desc. des coquilles foss. des
environs de Paris, II, p. 325, pl. 51, figs. 3, 4.

The carina of this mutation is also very strong, but the nodes, are more
widely spaced and more prominent than in the mutation brontes. The
median row of nodes is obsolete and the upper row is poorly developed.

Potamidopsis tricarinata mut. doris mut. nov.

1824. Cerithium tricarinatum var. d DESHAYES, Desc. des. coquilles foss. des
environs de Paris, II, p. 326, pl. 51, fig. 6.

This mutation is similar to the last, but in this form it is the sub-
sutural row of nodes which becomes obsolete.

.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE 69

Potamidopsis tricarinata mut. eris mut. nov.

IS24. Cerithium tricarinatum var. e DESHAYES, Desc. des coquilles foss. des
environs de Paris, II, 326, pl. 51, figs. 4, 7.,

On this species the carina is not prominent, and its nodes are nearly
obsolete, leaving the margin but slightly wavy. ‘The two upper rows of
nodes are present.

Potamidopsis tricarinata mut. fatua mut. nov.

1824. Cerithium tricarinatum var. f DesHayers, Desc. des coquilles foss. des
environs de Paris, II, p. 326, pl. 51, fig. 9.

This is an extreme mutation, which is distinguished by the almost
entire absence of nodes, in the adult stages, from both the carina and the
two spirals above it. The variation is carried so far in this form that it
would be described as a distinct species if the nodes had altogether disap-
peared.

Potamidopsis acus Deshayes

1866. Cerithium acus DESHAYES, Desc. des animaux sans vert. découverts dans
le bassin de Paris, III, 199, pl. 75, figs. 19, 20.

MEASUREMENTS (Deshayes) : Length, 25 mm.; greatest diameter, 6 mm.

Deshayes records the discovery of a single specimen only of this species.
According to his figures and description, it has a long, slender spire of
twenty-five volutions. The adult is ornamented by two rows of nodes
connected by ribs, the lower row being more prominent than the upper.
A fine undulating spiral is present just above the suture.

The aperture is like that of P. tricarinata, except that it does not show
gerontic characters in the thickening of the shell and loss of ornamenta-
tion seen on many specimens of the former species.

Deshayes calls attention to the similarity of this shell to the young
P. tricarinata, and it might be considered the young of that species were
it not that all the specimens of P. tricarinata studied, of 25 mm. in
length or of twenty-five volutions, have passed beyond the stage repre-
sented by the last whorl of P. acus in the intercalation of a finely nodose
spiral between those already existing. If P. acus is actually adult, as it
appears to be, it represents a more primitive form than P. tricarinata
and may well be the immediate ancestor of that species. This hypothesis
would be confirmed if other specimens showing young stages similar to
those of the very young P. tricarinata were discovered.

HORIZON AND LOCALITY: Calcaire grossier. Monchy, Paris Basin.

"0 ANNALS NEW YORK ACADEMY OF SCIENCES

Potamidopsis mixta Deshayes

—. Cerithium mixtwm DEFRANCE, Nom. nud.

1824. Cerithium mixtwn DESHAYES, Desc. des coquilles foss. des environs de
Paris, II, 324, pl. 45, figs. 6-11.

1866. Cerithium mixtwn DrsHAyYES, Desc. des animaux sans vert. découverts
dans le bassin de Paris, III, 123.

1906. Ptychopotamides mixtum CosSSMANN, HEssais de Paléoconch. Comp., VII,
108.

MEASUREMENTS: Length of the eleven volutions preserved, 41 mm.; greatest
diameter, 15 mm.; apical angle, 27.5°, changing to 21.8° on last three volu-
tions; sutural angle, 80°.

The youngest volution preserved on the shell studied is 3 mm. in diam-
eter; hence a considerable portion of the apex has been broken away.
The first three volutions are much worn, destroying all the finer surface
features, but the fourth has precisely the ornamentation of P. tricarinata
mut. brontes, namely, a strong nodose carina near the base of the volu-
tion, a sub-sutural row of rather strong nodes and a median row of
nodes much finer than either of the others. This remains the ornamenta-
tion of the shell until the third from the last volution, when the sub-
sutural and the lowest row of nodes become equal in strength, finer and
much crowded. A fourth, finely nodose carina is developed at the base
of the volution and is partially concealed by the succeeding whorl. On
the body volution the nodes of the upper row are small and in places so
elose together as to become confluent. Two nodose carine and several
fine spirals are present on the lower slope of the body volution.

The aperture is similar to that of P. tricarinata, with an expanded
callus on the inner lip and a comparatively long, twisted siphonal canal.
A slight columellar plication defines the posterior margin of the canal.
The outer lip is broken in the specimen at hand, but the figures of
Deshayes, cited above, show it to be similar to that of P. tricarinata.

HorRIZON AND LOCALITIES: Sables Moyens. Anvers and other localities in the
Paris Basin.
No. 20147, Columbia University collection.

REMARKS: So far as can be determined, the life history of this species
is like that of P. tricarinata until the last three volutions, when the orna-
mentation changes to that of three rows of crowded nodes, the uppermost
being slightly more prominent than the lowest. It is probably a de-
scendant of P. tricarinata, showing its divergence from its ancestor on
the last three volutions only.

The columnellar plication which furnishes the reason for placing this

WOOD, PHYLOGENY OF CERTAIN CERITHIIDE "1

ms

species in the genus Ptychopotamides is indistinct, and does not consti-
tute a sufficient reason for separating the species from the group to which
it is closely related in its development.

Potamidopsis tuberculosa Lamarck

1804. Cerithium tuberculoswm LAMARCK, Ann. du Mus. Nat. d’hist. naturelle,
III, 348.

1824. Cerithium tuberculosum DrsHayes, Desc. des coquilles foss. des environs
de Paris, II, 48, figs. 1-5.

1866. Cerithium tuberculosum DrsHAYES, Desc. des animaux sans vert. décou-
verts dans le bassin de Paris, III, 122.

1906. Serratocerithium tuberculosum CossMANN, Essais de Paléoconch. Comp.,
Wi, ia:

MEASUREMENTS: Length, 38 mm.; greatest diameter, 12.2 mm.; apical angle,
26°; sutural angle, 86.4°.

The early stages of this species are described from a young individual
of fifteen volutions. ‘The protoconch of the specimen is missing, and the
first two volutions are too much worn to show the surface ornamentation,
but the third volution present is ornamented by a sub-sutural spiral and
a stronger spiral forming a shoulder angle just above the suture. Both
spirals are rendered nodose and connected by ribs which are continuous
across the volutions. This type of ornamentation persists for five volu-
‘tions and is closely similar to the ornamentation of P. tricarinata at a
slightly later stage. ‘The nodes of the lower and upper rows gradually
become equal in strength, and the shoulder disappears. On the sixth
volution of those preserved a spiral is intercalated between the two rows
of nodes already formed, and two volutions later this spiral is broken up
into a row of very fine nodes. The ornamentation at this stage resem-
bles that of P. tricarinata at the same stage, except that the lower row
of nodes is more prominent on the latter species. At the eleventh volu-
tion the nodes of the sub-sutural row become more prominent and more
widely spaced than those of the lowest row. This tendency increases
until a shoulder angle composed of strong, transversely elongate nodes
is formed just below the suture. This becomes the ornamentation of the
adult shell, except that a fourth spiral which is partially exposed just
above the suture also becomes wavy or faintly nodose. The body volu-
tion bears one nodose ridge in addition to those already described and
several fine spirals on its lower slope.

The aperture is nearly circular. The callus of the inner lip is broad
and thin. The outer lip is thin; its margin, growing more rapidly at

12 ANNALS NEW YORK ACADEMY OF SCIENCES

Hie sig hia ©
the anterior portion, gives it a sinuous outline. The siphonal canal is
broad and deep, bordered by a strong ridge on its columellar side.

HorIZON AND LOCALITIES: Sables Moyens (Upper Hocenic). Widely distrib-
uted in the Paris Basin.
No. 20148, Columbia University collection.

Remarks: The earliest volutions of this shell are missing, but the
youngest preserved has an ornamentation similar to that of the ninth to
the thirteenth volutions of Potamidopsis tricarinata. It adds an inter-
calated spiral as in the latter species, but it diverges from the line of evo-
lution represented by P. tricarinata by forming its shoulder angle at the
upper instead of the lower margin of the whorl. This species may be
regarded as derived from the same ancestral stock as P. tricarinata, but
it represents a divergent line of evolution.

M. Cossmann refers this species to Serratocerithium, a sub-genus
founded mainly on characters of the aperture, but the aperture of P.
tuberculosa does not appear to differ to a marked degree from that of
P. tricarinata. The canal is slightly longer and the outer lip thinner
and less flaring. The present reference of the species, being founded on
descent as revealed by the ontogeny, necessarily arrives at a different
result from one founded on adult characters alone.

Potamidopsis roissyi Deshayes

1824. Cerithium roissyi DESHAYES, Desc. des coquilles foss. des environs de
Paris: Il, 322, pl. 50; figs. 13-20:

1866. Cerithiwm roissyi DESHAYES, Desc. des anim. sans vert. découverts dans
le bassin de Paris, p. 127.

1906. Tympanotonus roissyi COSSMANN, Wssais de Paléoconch. Comp., VII, 120.

MEASUREMENTS: Length, 25.7 mm.; greatest diameter, 8 min.; apical angle,
20°; sutural angle, 90°.

The protoconch is missing from the best specimen available, and it is
probable that two or three more volutions are also broken away. The
youngest volution present is .7 mm. in diameter, and it has exactly the
ornamentation of P. tricarinata from the ninth to the thirteenth volu-
tions. The same ornamentation continues for four volutions, after
which the ribs disappear and the two rows of nodes become equal in
strength and often alternate in position as compared across the whorl.
On the sixth volution a fine spiral is intercalated at about the middle of
the volution. This spiral soon breaks up into a row of extremely fine
nodes. At about the same stage of growth the sub-sutural row of nodes
becomes stronger than the others, a tendency which increases until the

©

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 73
adult condition is reached. The ornamentation of the adult consists of
three rows of nodes of which the upper are larger and more widely spaced
than the others, and the nodes of the median row are very fine. An
irregularly nodose fine spiral is barely visible just above the suture. The
body volution has two strong spirals below those already mentioned. On
this volution the growth lines become very much crowded, and all the
nodes become indistinct, especially toward the later part of the volution.

The aperture is about equal in length and breadth and is roughly quad-
rangular in outline. The callus of the inner lip is broad and thin. The
siphonal canal is short, widely open and somewhat twisted. The outer
lip is thin and has a strongly sinuous outline.

HorIzON AND LOCALITY: Sables Moyens superieur (Upper LHocenic). La
Chapelle, Paris Basin.
No. 20149, Columbia University collection.

Remakks: The ornamentation of this species closely resembles that of
P. tuberculosa, both in its development and in the adult stage. The
species differs from P. tuberculosa in its smaller size; narrower apical
angle, which makes it a more slender shell; its shorter canal and more
angular aperture.

This species bears the same relation to P. tricarinata as does P. tubercu-
losa—that is, it is derived from the same ancestor as both, but develops
in the direction of P. tuberculosa, to which it is closely related.

Potamidopsis crassinoda sp. nov.

MEASUREM.£NTS: Length of specimen with apical whorls missing, 39.8 mm.;
greatest diameter, 26.7 mm.; apical angle, 82°, changing to 23.8° on the sixth
volution; sutural angle, 85°.

This species is distinguished from Potamidopsis tuberculosa, to which
it is closely related, in being a larger and thicker shell and in having the
nodes of the surface much larger and more prominent. This difference
begins at an early stage of growth and continues throughout the life of
the animal. The youngest volution preserved is 2.5°mm. in diameter,
and several whorls have evidently been broken away above this. The
first three volutions have an ornamentation of about the same strength
and character as the adult of P. tuberculosa, but beyond this the large
nodes characteristic of all the later volutions are developed. The nodes
of the uppermost row are large, blunt cones; those of the lowest row,
smaller and transversely elongate. The median nodes are very fine and
on some specimens nearly obsolete. The base of the volution is produced
into lobes, which sometimes overhang the succeeding volution.

v4 ANNALS NEW YORK ACADEMY OF SCIENCES

(free

The aperture is similar to that of P. tuberculosa, but the canal is
longer and more strongly reflexed, and the callus of the inner lip is
thicker and is not closely applied to the surface of the shell. The outer
lip is thickened with crowding of the growth line and loss of ornamenta-
tion for some distance back of it.

HorIZON AND LOCALITY: Sables Moyens. Rosoy-en-multiens, Paris Basin.
No. 20150, Columbia University collection.

REMARKS: This species has been regarded as a variety of Potamidopsis
tuberculosa, but its much greater size, strongly marked surface features,
and longer siphonal canal, as well as its more accelerated development,
entitle it to rank as a distinct species. It is evidently derived from the
same ancestor as P. tuberculosa, following the same path of evolution
but strengthening all the features of the shell. The three species, P.
roissyt, P. tuberculosa and P. crassinoda, possess the same type of orna-
mentation, and they form a series in which P. roissyi is at one extreme,
characterized by small size, thin shell and delicacy of ornament, and
P. crassinoda, at the other, characterized by thick shell, strong tubercles
and wide apical angle.

Potamidopsis conjuncta Deshayes

1824. Cerithium conjunctum DESHAYES, Dese. des coquilles fossiles des en-
virons de Paris, II, 387, pl. 73, figs. 14.

1866. Cerithiwm conjunctum DESHAYES, Dese. deS animaux sans vert. décou-
verts dans le bassin de Paris, III, 128, pl. 80, figs. 9-16.

1906. Tympanotonus conjunctus COSSMANN, Essais de Paléoconch. Comp., VII,
120.

MEASUREMENTS: Length of specimen from which apex is broken, 29.4 mm.;
greatest diameter, 10.8 mm.; apical angle, 28.2°, changing to 18.2° on the last
three volutions; sutural angle, 86°.

The youngest volution available for study is 2 mm. in diameter, and
several volutions have been broken away above it. The ornamentation
is that of two rows of nodes, one near each suture, the lower row being
the more prominent. The upper and lower nodes are connected by ribs.
This ornamentation resembles that of P. tricarinata from the ninth to
the thirteenth volutions. On the third volution present a fine spiral is
intercalated between the two rows of.nodes. This spiral soon becomes
finely nodose, and the ornament of the adult is that of three rows of
nodes of which the uppermost and lowest are large and of equal size,
while the nodes of the median row are very small. The body volution
has two strong spirals and several fine ones on its lower slope.

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA W5

The aperture is roughly quadrangular. The callus of the inner lip is
thick and expanded posteriorly. The siphonal canal is short, twisted
and has a strong columellar ridge defining its posterior margin. The
outer lip is broken in the specimens studied, but, according to the figures
of Deshayes, cited above, it is thin and strongly sinuous.

HORIZON AND LOCALITY: Oligocenic. Jeures, Paris Basin.
No. 20151, Columbia University collection.

ReMARKS: The development of this shell is closely similar to that of
P. tricarinata, so far as can be determined from the specimens studied.
The adult differs only in the fact that the lowest row of nodes equals the
uppermost in prominence, instead of exceeding it. This causes the out-
line of the volution to be parallel with the slope of the spire, instead of
forming a shoulder. P. conjuncta probably occupies about the same
relation to P. tricarinata as does P. tuberculosa, diverging from the tri-
carinata line of evolution at about the same stage in its development, but
in a different direction. The adult of P. tricarinata shows greater prom-
inence of the lowest row of nodes; that of P. tuberculosa emphasizes the
prominence of the sub-sutural row, and in P. conjuncta they are equal.

Potamidopsis trochleare Lamarck

1804. Cerithiwm trochleare LaMaARcK, Ann. du Mus. d@’hist. naturelle, III, 349.

1824. Cerithium trochleare DESHAYES, Desc. des coquilles foss. des environs de
Paris, TT, 388; pl: 55, figs. 10; 11.

1866. Cerithium trochleare DESHAYES, Desc. des animaux sans vert. découverts
dans le bassin de Paris, III, 129, pl. 80, figs. 1-8.

1906. Tympanotonus trochleare COSSMANN, Essais de Paléoconch. Comp., VII,
118, pl. 11, fig. 19.

MEASUREMENTS: Length, 25 mm.; greatest diameter, 12 mm.; apical angle,
25.2°; sutural angle, 85°.

One of the specimens studied shows the protoconch. This is similar in
form to the protoconch of Cerithium adansoni and comprises about one
and one-half volutions. The volutions immediately succeeding the proto-
conch on this specimen are poorly preserved; but another specimen,
whose youngest volution is .7 mm. in diameter, retains the surface feat-
ures. This is the third volution, as shown by comparison with a com-
plete individual. It is ornamented by two nodose spirals, of which the
lower is the more prominent, and a third fine intercalated spiral. This
is the ornamentation of the adult P. tricarinata. The median spiral per-
sists for two volutions only, after which the shell has two rows of nodes
only, with the lower more prominent than the upper. ‘The latter stage

76 ANNALS NEW YORK ACADEMY OF SCIENCES

lasts for a variable number of volutions on different specimens, but
usually from five to eight volutions. Beyond this the ribs disappear,
and the shell is ornamented for the remainder of its growth by two ex-
tremely prominent continuous spirals with deep concave depressions
between them. A third spiral, partly concealed by the embracing of the
whorls, is shown on the body volution to be less prominent than the
others.

The aperture is distinctly quadrangular. The callus of the inner lip
is thick and rather narrow. ‘The siphonal canal is short and deep. The
outer lip is often thickened in large individuals, sinuous and folded into
lobes to correspond with the spirals of the outer surface.

HorIzON AND LOCALITIES: Oligocenic. Morigny, Jeures and many other local-
ities in the Paris Basin. :
No. 20152, Columbia University collection.

Remarks: The youngest volution of this species to show the surface
has the ornamentation of the adult P. tricarinata. The first change to
take place in this ornamentation is in the loss of the median spiral, which
was the last feature to be acquired in the development of the latter spe-
cies. The succeeding three or four volutions of P. trochleare correspond
with a still younger stage of P. tricarinata, namely, that with two rows
of nodes only. The adult P. trochleare has two continuous spirals, as
in the earliest stages of P. tricarinata. The facts thus far stated seem
to indicate a loss of characters by gerontism and the return to the primi-
tive conditions of an ancestor, but that this is not the case is shown by a
study of the intervening stages of P. tricarinata. Studying the develop-
ment of that species in reverse order, the stage preceding that with two
rows of nodes only is one in which the sub-sutural row of nodes is absent,
and, earlier still, a fine spiral is present immediately above the shoulder
spiral (plate vim, fig. 7). This is not the same feature as the median
row of nodes in the adult, although it occupies the same position, because
it disappears and gives place to another character before the appearance
of the adult median nodes. It is this spiral, however, which, on the
fourth volution, is as strong as the spiral at the shoulder angle and forms
the upper of the two continuous spirals on the second volution. In P.
trochleare, on the contrary, it is the sub-sutural spiral which persists and
forms the upper of the two strong spirals in the adult. The lower of the
two corresponds with the spiral at the shoulder angle in P. tricarinata.
These two spirals have not the character of primitive structures, but are
on the contrary, extreme in their development. P. trochleare is a de-
scendant of P. tricarinata, with its youngest stages like the adult of the

WOOD, PHYLOGENY OF CERTAIN CERITHIIDEA ie

latter species. From this stage it progresses toward simplification of sur-
face forms rather than complication of them, as in the species previously
described. It illustrates the fact that progressive development does not
always mean Complication of structures, but may also travel in the direc-
tion of simplification of structures. Although P. trochleare does not
add new types of ornamentation, it does emphasize strongly the one
feature retained in the extreme prominence of its two continuous spirals.

Illustrations of progressive development resulting in more simple struc-
tures are found in other genera; for example, Claviger matonit GRAY has
young stages in which the whorls are ornamented by four strong spirals
crossed by numerous oblique ribs, changing abruptly to an ornamentation
of two very prominent continuous spirals, but without other features to
indicate gerontism as a cause for the loss of ornamentation.

Deshayes’s figures of this species, cited above, indicate an extreme de-
gree of variation, including forms with three spirals, or one spiral, or
rows of strong nodes, and it is probable that several of these should be
considered distinct species. In the absence of specimens showing these
variations, they will not be considered here.

5. Vulgocerithium

Vulgocerithium minutum de Serres

1822. Cerithiwm minutum vE Serres, Essai pour servir a Vhistoire des anim.
du midi de la France, p. 60.

1856. Cerithium minutum HORNES and PaRTscH, Abhand. der k. k. geol. Reich-
sanst., III, 390, pl. 41, figs. 8, 9.

MEASUREMENTS: Length, 25 mm.; greatest diameter, 9 mm.; apical angle,
33.5°, changing to 16° on the last four volutions; sutural angle, 83.5°.

The youngest volution preserved on the specimen studied is 1.2 mm. in
diameter. It has a well-defined shoulder with two strong spirals, one
finer intercalated spiral and four on the shoulder. On the next two
volutions the sub-sutural spiral becomes broad, another spiral is added
between the two primaries, and one appears on the lower slope of the
whorl. On the succeeding volutions the sub-sutural spirals become ele-
vated at intervals as a row of nodes, the lower slope of the volution be-
comes nearly continuous with its vertical sides and numerous intercalated
spirals appear. The adult ornamentation is that of a sub-sutural row of
nodes, a median row with nodes slightly more prominent than those of
the upper row and ribs which are more or less continuous toward the
upper suture but are represented by irregularly spaced nodes below the

78 ANNALS NEW YORK ACADEMY OF SCIENCES

‘

median line. The shoulder on the last three volutions is nearly obsolete,
being defined merely by the median row of low nodes.

The aperture is of the form usual in this group, with a narrow callus
on the inner lip, a strong posterior tooth and a short anterior canal. The
outer lip is thin and slightly crenulated.

HorRIzON AND LOCALITY: Upper Oligocenic (Aquitanian). Saucats, France.
No. 3123, Museum of Comparative Zoology.

REMARKS: This species continues into the Miocenic, but the specimens
studied are from the Oligocenic. Except for its small size, the shell is
closely similar to V. vulgatum, and it may well be the immediate ancestor
of that species.

Vulgocerithium pupzforme Basterot?

1825. Cerithium pupeforme Bastrerot, Mémoire géol. sur les environs de Bor-
deaux, p. 58, pl. 3, fig. 18.

1906. Dizoniopsis pupeforme CosSMANN, Essais de Paléoconch. Comp., VII,
147, pl. XII, figs. 22-24.

MEASUREMENTS: Length, 12 mm.; greatest diameter, 4.8 mm.; apical angle,
36.5°, changing to 26° on the last three volutions; sutural angle, 76°.

The protoconch of this species is not preserved, but a volution .6 mm.
in diameter probably represents about the second volution beyond it.
This whorl] is ornamented by two equal spirals, and on the next volution
the spirals are crossed by ribs. On the third volution of those preserved
a spiral is added between the two primary spirals and one just below the
suture. On the later volutions numerous fine spirals appear until those
of the third order may be recognized. On the body volution the shoulder
is less prominent and the nodes formed by the crossing of the ribs and
the sub-sutural spiral are larger, so that without a lens the surface ap-
pears to be ornamented by two rows of nodes, the lower of which is formed
by the crossing of the ribs and the shoulder. The body volution has two
or three strong spirals, with finer intercalated ones on its lower slope.

The aperture is elongate oval, with a broad and thick callus on the
inner lip. The siphonal canal is long and slightly curved. The outer
lip is thin and not expanded.

HorIzON AND LOCALITY: Oligocenic (Aquitanian). Saucats, near Bordeaux.
No. 2521, Museum of Comparative Zoology.

ReMARKS: The original description of Cerithiwm pupeforme has not
been obtainable, and the reference to this species is somewhat doubtful.

WOOD, PHYLOGENY OF CERTAIN CERITHUDA 79

The development of this shell, as well as its adult ornamentation, has
all the characteristics of Vulgocerithium. It resembles V. minitum to
such an extent that it was at first thought to be the young of that species,
but it is more accelerated than V. minutum, acquiring its tertiary spirals
at an early stage. It differs further from the latter species in having a
narrower aperture and longer canal. The well-developed callus and
nearly uniform size of all of the ten individuals studied seem to indicate
that the specimens are fully adult.

F. CRETACIC SPECIES OF CERITHIUM

No actual specimens of true Cerithiwm from horizons earlier than the
Aptien were available for study, and the following phylogeny worked out
from the literature is subject to revision, if more material should be
obtained.

Cerithium cornuelianum d’Orbigny

1842-1843. Cerithiwm cornuelianum bD’ORBIGNY. Paléontol. Francaise, Terrains
Crétacés, II, Gastéropodes, p. 361, pl. 228, figs. 11-13.
1906. Atresius cornuelianum COSSMANN, Hssais de Paléoconch. Comp., VII, 195.

The original description is as follows:

DIMENSIONS: Ouverture de l’angle spiral, 27°; longeur totale, 27 millim. ;
largeur, 12 millim.; longeur du dernier tour, par rapport a l’ensemble 35/100;
angle sutural, 89°.

Coquille allongée, turriculée. Spire formée d’un angle régulier, composée
de tours convexes, ornés en travers, a la derniére révolution spirale, de dix
cdtes flexuenses, ondulées, non arrétées, se correspondant obliquement d'un
tour A l'autre. Sur ses cdtes viennent se croiser de légers sillons longitudi-
naux trés-inégaux. Bouche ovale, prolongée en avant et terminée par un
sinus; labre trés-échancré en arriére, saillant antérieurement.

Horizon AND LOCALITY: Aptien. Grange-au-Ru, near the Varin bridge, com-
mune de Wassy (Haute Marne).

Remarks: This species has volutions of a rounded outline, ribs con-
tinuous across the whorl and numerous spirals of different orders. It is
thus a simple shell, having the characteristics which might be expected
in an early type of true Cerithium. <A specimen in the Museum of Com-
parative Zodlogy does not show the young stages, but on the last three
volutions two of the spirals are stronger than the others. This suggests
the beginning of the development which becomes a characteristic feature
of Cerithium equispirale and later species of the genus.

A posterior tooth is not developed on the inner lip, but this would
hardly be expected before the spirals have become strong on the body

S0) ANNALS NEW YORK ACADEMY OF SCIENCES

volution, for the presence of such a tooth appears, in many cases, to be
due to a strong spiral on the body volution, which projects into the aper-
ture and is accented by the passage of the callus over it.

M. Cossmann refers this species to Atresius, but in the description of
that genus, the beak is said to be large and bent backward and the spire
to be ornamented by nodulose cost, characteristics which do not appear
on this species. It seems to bear little resemblance to the type of the
genus Atresius.

Cerithium albense d’Orbigny

1842-1848. Cerithium albense v’OrRBIGNY, Paléontol. Francaise, Terrains Cré-
tacés, II, Gastéropodes, p. 355, pl. 227, figs. 10-12.

The original description is as follows:

DIMENSIONS: Ouverture de l’angle spiral, 20°; longeur totale, 18 millim. ;
diamétre, 4 millim.; longeur du dernier tour, par rapport 4 l’ensemble, 30/100.

Coquille trés-allongée, aciculée. Spire formée d’un angle régulier, composée
de tours convexes, séparés par des sutures, ornés, en long, de cdtes inégales,
dont quatre, plus grosses, plus saillantes, tranchantes, vont diminuant de
grosseur des supérieures aux inférieures. Entre chacune de celles-ci existe
une petite cote trés-étroite; il y a encore, en travers, par révolution spirale,
de onze ou douze cdtes arrondies, droites, sur lesquelles passent les premiéres.

Le dernier tour a de plus une seule céte longitudinale. Bouche ovale, pro-
longée en canal, en avant. Labre mince, tranchant.

Horizon AND LOCALITY: Neocomian. Marolles (Aube), France.

Remarks: The figures of this species show a simple type of shell with
rounded volutions, well-developed ribs and three strong spirals on each
volution. A finer fourth spiral is also present just below the suture, and
the shell is further ornamented by a single intercalated spiral between
each pair of the coarser ones. The outer lip has the crenulated margin
characteristic of C. wquispirale and later species of Cerithiwm.

This shell is simpler than C. cornuelianum in possessing two orders of
spirals only, and, so far as can be determined without an examination of
the shell, it seems to constitute an earlier member of the Cerithiwm line
of evolution.

@. JURASSIC SPECIES OF CERITHIUM

Cerithium corallense Buvignier

1843. Fusus corallensis BuvigNIER, Mémoire de la Soc. Philomatique de Verdun,
OP ej Oleyy Mayen Nore 7 :

1889. Brachytrema corallensis DE Loriot, Abh. Sweiz. Paliont. Gesell., XVI, 65,
DIO hes. WF 2:

1906. Brachytrema corallensis CoSSMANN, HEssais de Paléoconch. Comp., VII,
p. 18.

——

WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 81

The original description of this species is as follows:

Coquille turriculée, allongée, A cotes longitudinales, au nombre de cinq sur
les tours supérieurs, mais plus nombreuses sur les autres; elles sont recoupées
par des sillons transverses au nombre de trois sur chaque tour. Bouche ovale,
anguleuse supérieurement, 6chancrure large, profonde et oblique.

HORIZON AND LOCALITY: Jurassic, Coral-rag. St. Michiel, France.

REMARKS: This species of Cerithiwm shows primitive characteristics
in its simple ornamentation consisting of primary spirals and ribs only,
its moderate degree of embracing of the whorls and its simple aperture,
with short, straight canal. The points of intersection of the spirals and
ribs are often elevated, giving the surface a nodose appearance, but the
ornamentation is composed essentially of the ribs and three simple spirals
only. In this respect the shell is more primitive then C. albense and
must resemble the young of that species before the introduction of inter-
calated spirals.

Specimens of this species were not obtainable, but from the evidence
furnished by the literature it seems to be an ancestral form of Cerithium
and the earliest representative thus far obtained of the line of evolution
terminating in C. tuberosum.

This species has been referred to the genus Brachytrema, but a com-
parison with the type of that genus, B. buvigniert, shows a wide contrast
in form and ornamentation, the latter species having the low spire and
wide apical angle of the genus Trochus, with the outer lip much ex-
panded and the body volution longer than the remainder of the shell.

V. SUMMARY

Reviewing the facts already presented, it is found that, while no speci-
mens of true Cerithiwm were obtained earlier than the Aptien, it appears
from the literature that the Jurassic species, Cerithiwm corallense, may
represent the earliest known species of the genus. This is a primitive
type of shell of small size, with rounded whorls and having on its adult
volutions three spirals crossed by ribs.

In studying the development of retarded species of Cerithiwm, it is
found that the shell forms first a single spiral, with a second spiral added
above the first. Later the two spirals become of equal strength and are
crossed by ribs. This stage reappears constantly throughout the genus
and its near relatives. The fact that it is so persistent a feature suggests
that it probably formed the adult stage of an early Jurassic or Triassic
ancestor of Cerithium, from which forms like C. corallense were devel-

82 ANNALS NEW YORK ACADEMY OF SCIENCES

oped by the addition of a third spiral above the two primary ones. Such
a type of development is epitomized in-three species of the upper Eocenic.
C. bicarinatum has adult ornamentation like the supposed primitive an-
eestor of C. corallense—that is, two equal spirals crossed by ribs (plate
Iv, fig. 9). The immediate descendant of the former species is C. bicari-
natum mut. trispirale, a form which corresponds with C. corallense in
having a third spiral present above the two primary ones, producing a
shell with rounded volutions and an ornamentation of three simple spirals
crossed by ribs.

The lower Cretacic species, C. albense, shows an advance upon C.
corallense in the introduction of intercalated spirals, and it has its par-
allel in the Eocenic species, C. retardatum, which differs from its imme-
diate ancestor, C. bicarinatum mut. trispirale, only in the presence of
intercalated spirals. C. bicarinatum is descended from an early ancestor
of Cerithium, and is so retarded as to retain its ancestral characteristics
nearly unchanged. Its descendants pass through rapidly, in one geo-
logical period, a path of evolution which has been traveled more slowly
in the main line of evolution from early Jurassic, or possibly Triassic, to
Cretacic time.

An advance upon the type of development shown in C. albense is seen
in C. cornuelianum, of later Cretacic (Aptien) time. This shell has
many intercalated spirals, and two of the primary spirals are stronger
than the others, forming a slight projection around the median portion
of the adult volutions. This projection, although similar in form, is not
the developmental equivalent of the primary two-spiraled stage, for in
the phylogeny of the genus it appears after the stage with three primary
spirals and after the development of intercalated spirals. In recent,
highly accelerated species of the genus, intercalated spirals appear so
early in the ontogeny that the stage with three simple spirals is either
omitted altogether or obscured by the fact that the third spiral on the
shoulder never becomes as strong as the others. In such cases the stage
just described seems to be continuous with the primitive two-spiraled
stage, from which it differs morphologically only in the presence of in-
tercalated spirals.

The greater abundance of Eocenic material in the collections studied
furnishes an opportunity for determining the phylogeny with greater
certainty than in the earlier horizons. At that time C. equispirale rep-
resents the next stage in the phylogeny of the genus beyond C. cornue-
lianum, for on this specimen the two equal spirals are well developed and
persist to the adult whorls, and spirals of several orders are easily recog-
nizable. The young stages of C. equispirale are unfortunately missing,

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 83

but they were doubtless simpler than the youngest stage preserved, and
were probably not unlike the young specimens referred to C. inabsolu-
tum; but if these specimens are correctly idenified, the adult differs from
C. equispirale in the direction of loss of fine spirals and of the shoulder.
C. lamellosum carries this loss of ornament still farther, and the two
constitute a lateral branch in the phylogeny of Cerithium. C. calcitra-
poides represents another lateral branch, having its young stages like the
adult C. cornuelianum, but its later stages have a shoulder with a sharp
angle of the type seen on recent species of the genus.

As stated above, the European Miocenic and Pliocenic furnish no un-
doubted species of Cerithiwm sens. str., but in the Miocenic of Florida
C. chipolanum seems, so far as can be determined from the description
and figure, to belong to this genus and to represent a branch in which a
comparatively low spire is developed. C. chipolanum is probably an
American representative of an undescribed European form which was
the ancestor of the somewhat low-spired recent species, such as C. adan-
sont, C. echinatum, etcetera.

The Pliocenic C. callisoma has the high spire characteristic of the type
of the genus C. tuberosum, and it, too, probably had its European par-
allel, which was the ancestor of C. tuberosum and other high-spired re-
lated forms. The abundance of material in the collections of recent
shells reveals a great flowering out of the genus in recent time, and how-
ever different the appearance of the adult shells, all reveal their common
ancestry by a similarity in their young stages, as described above and indi-
cated on plate I.

Among the genera closely related to Cerithiwm, Vulgocerithium is per-
haps the nearest, developing as it does at an early stage the two strong
spirals with intercalated spirals, and diverging from the main line of
evolution only in the greater development of nodes and in the absence
of a sharp shoulder angle in the adult. Species of this genus seem to
undergo little change from Oligocenic to recent time, and all the species
described are similar in general appearance and differ from one another
only in details.

The genus Potamides is closely related to Cerithtum. The type of the
genus P. lamarcki develops the bicarinate ornamentation in the same
manner as in C. retardatum (plate 111, figs. 9, 10, and plate tv, fig. 9)
or other retarded or primitive species of Cerithiwm, but retains each
stage for a greater portion of the spire, or, in other words, its early on-
togeny is like that of Cerithiwm, but more retarded. The adult expresses
its divergence from Cerithiwm by developing nodes as the chief feature of
its ornamentation. As pointed out above, Potamides is a more primi-
tive genus than Cerithiwm in its slightly developed canal, in the sim-

84 ANNALS NEW YORK ACADEMY OF SCIENCES

plicity of its ornamentation and in its retarded ontogeny. It is probably
developed from the same bicarinate ancestor from which Cerithium arose,
but includes primitive types which persist throughout several periods of
geological time. ocenic species of Potamides form, lke Vulgoceri-
thium, a compact group the members of which do not diverge strongly,
even in the adult stages.

The genus Tympanotonus is founded upon Murex fuscatus LINNE, a
species formerly referred to Potamides, and this shell has the typical
Potamides young stages, forming the peculiar ornamentation of the adult
by developing its median row of nodes into large spines. The genus
should be restricted to those forms which are like Potamides in the young
and only show divergence in the neanic or adult stages. As thus re-
stricted, the genus is a direct descendant from Potamides.

The genus Potamidopsis, having for its genotype Cerithium tricarinatum
LAMAROK, is also closely related to Cerithiuwm, as shown by the develop-
ment of the genotype. ‘This species forms a bicarinate ornamentation in
the same manner as both Cerithiwm and Potamides (compare plate vit,
figs. 7, 8, with plate 111, figs. 9, 10, and plate rv, fig. 9), but it is more
accelerated than Potamides. Beyond this stage, Potamidopsis diverges
strongly from Cerithium in forming its shoulder angle just above the
suture and in having its surface ornamented by rows of nodes. The
genus as a whole is less accelerated than Cerithium.

As a probable ancestor of P. tricarinata we have P. acus, whose adult
stages resemble the ninth to the thirteenth volutions of P. tricarinata,
and from this species we have developed P. roissyi and P. tuberculosa,
whose development is parallel to that of P. tricarinata up to the P. acus
stage. After this stage these forms diverge from P. tricarinata by de-
veloping the uppermost instead of the lowest row of nodes.

The ancestor of Cerithium immediately preceding the Jurassic species
described probably possessed a bicarinate ornamentation crossed by ribs
and a very slightly developed canal. The young stages probably had
rounded whorls, with one spiral at first and later two continuous spirals.
The collections thus far studied do not furnish sufficient evidence for a
statement as to the canalless form from which this primitive ancestor of
the genus was derived.

Cerithium is a genus which shows a strong tendency to vary, as shown
by the great diversity of forms present in the EKocenic and still greater
variety in recent time; but, notwithstanding the wide differences in
adults, relationship may be traced by similarity in the young stages,
pointing out the path of evolution which all have traveled.

85

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ

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86 ANNALS NEW YORK ACADEMY OF SCIENCES

LITERATURE.

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ADANSON, M.: Histoire Naturelle du Sénégal. Avec le Relation abrigée d’une
Voyage faite en ce pays, pendant les années 1749-53. Paris. 1757.

von ATH, A.: Die Versteinerungen des Nizniower Kalksteines. Beitrige zur
Paliontologie und Geologie Osterreich-ungarns und des Orients, I, 1 and
2 Theil, Heft III and IV. 1882.

pD’ARCHIAC, ET HAIME, JULES: Descriptions des animaux fossiles du groupe
nummulitique de l’Inde. 1853.

ARNOLD, RALPH: New and Characteristic Species of Fossil Mollusks from the
Oil-bearing Tertiary Formations of Southern California. Smithsonian
Miscellaneous Collections, XXXII, pp. 525-546. June, 1907.

ASCHER, ELsE: Die Gastropoden, Bivalven und Brachiopoden der Grodischter
Schichten. Beitriige zur Paliontologie und Geologie Osterreich-ungarns
und des Orients, Bd. XIX. 1906.

Barrois, CHARLES: Mémoire sur le Terrain Crétacé des Ardennes et des ré-
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pE Basterot, M. B.: Description des coquilles fossiles des environs de Bor-
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Exts. Mémoire della Reale Accademia delle Science di Torino, Série
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Beyricu, E.: Die Conchylien des norddeutschen Tertiirgebirges. Zeitschrift
d. Deutsch. Geolog. Gesellschaft, Bd. V. 1852.

DE BLAINVILLE: Dictionnaire des sciences naturelles. Mollusks. 1820.

: Fauna Franeaise. Mollusks. 1825.

BoOuM, JOHANNES: Die Gasteropoden des Marmolatakalkes. Paleontograph-
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——: Die Kreidebildungen des Fiirbergs und Sulzbergs bei Seigsdorf in Ober-
bayern. Paleontographica, XXXIII. 1891-1892.

Broccut, Di G.: Conchiologia fossile subappennina, II, Milano. 1814.

Brorul, FERDINAND: Die Fauna der Pachyecardientuffe des Seiser Alp. Scaph-
opoden und Gastropoden. Paleontographica, LIV. 1907-1908.

BRONGNIART, ALEXANDRE: Mémoire sur les terrains d’eau douce. Annales du
Muséum National d’histoire naturelle, XV. 1810.

Bronn, H. G.: Index paleontologicus. 1848.

: Italiens Tertiirgebilde. 1831.

Brown, THOMAS: Illustrations of the Fossil Conchology of Great Britain and
Ireland. Nos. I-IX. 1834-1838.

BruGcui@rRe: Histoire naturelle des Vers. Encyclopédie Méthodique, Tome I,
pt. 2, pp. 345-758. 1792.

BuVIGNIER: Mémoire sur quelques fossiles nouveau des departments de la Meuse
et des Ardennes. Mémoire de la Société Philomatique de Verdun. 1843.

a

WOOD, PHYLOGENY OF CERTAIN CERITHIIDZ 84

CHENU, J. G.: Manuel de Conchyliologie, I, pp. 279-284. 1859.

CoLUMN Fasit: De aquatilibus aliisque nonnullis animalibus. Roma. 1616.

CossMANN, Maurice: Contribution 4 la Paléontologie Francaise des Terrains
Jurassique Mém. de la société géologique de France, No. 14, V and VI.
Pls. XVI-XX. 1895.

—: Catalogue illustré des coquilles fossiles de l’Gocene des environs de
Paris, Appendice No. 38. 1902. Jbid. Quatriéme fascicule.

COSSMANN, MAvRICE, ET PIsSSARO, G.: Faune focénique du Cotentin, 1903.
Ma Ji

Bulletin de la Société Géologique de Normandie, XXII, pour 1902,
publié October, 1903.

CossMAN, MAuRICE: Observations sur Quelques Coquilles Crétaciques recueil-
lies en France. 1896-1903.

—: Essais de Paléoconchologie Comparée. Septiéme livraison. Juillet, 1906.

DAINELLI, G.: I] Miocene inferiore del Monte Promina in Dalmazia. Palon-
tologia Italica, VII, 285-285, pll. 29-33. 1901.

—: La fauna eocenica di Bribir in Dalmazia. Palzontographica Italica, XI,
Dieewied-Oleeplls 1.2.) 1905.

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: Lethzea Rossica. 1853.
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88 : ANNALS NEW YORK ACADEMY OF SCIENCES

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—: Conchyliologie fossile des Terrains Tertiares au Bassin dé l’Adour, En-
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WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 89

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90 ANNALS NEW YORK ACADEMY OF SCIENCES

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WOOD, PHYLOGENY OF CERTAIN CERITHIIDA 91

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92 ANNALS NEW YORK ACADEMY OF SCIENCES

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von ZirTet, K. A.: Die Gasteropoden der Stramberger Schichten. Palzeonto-
graphica. Beitrige zur Naturgeschichte der Vorwelt. Supplement. 1873.

PLATE I
SURFACE FEATURES OF CERITHIUM AND VULGOCERITHIUM

Diagram to illustrate the development of five surface features on eleven
recent species of Cerithium and Vulgocerithium vulgatum.
The numbers at the left of the plate indicate the numbers of the volutions,
the protoconch being numbered 1.
——=primary spirals.
| ==ribs.
x
} = outline of volution.
pal lnte OR of secondary and higher orders.
= nodes. °

Of

59 ee TP ileniaietiane Abhandlungen..
Wiripmosxe, G, ¥.: A Monograph of thei
‘fand (1891). The Paleontogranhiecal Sect
Wane, Wowreiat: Die Fang der sidbaye ‘iain nolesse. FF ui
‘.. » 807,, ‘Paleontograpbiea: SL VIL. Titi ASS oer i ee
Woon, ‘Sea tues Vi: Monograph of the. Co oti: vice ini we, en
. ciety Monographs, Tondon.. 184% aane i ae
Woop, Widtaw s Index testaceologittay oa ateinasie * bet 3
Foretgn. ome

) Ror Vat, 4
it. Sever hy

tants, Pano: “Die

sit Paws. I riparia stl. « Roan SOP Paina oe
» graphica. nota ee ee a

/ Taras . <i

otemineonsy sea wom saa SxS

VOLUME XX, Prawn 1.

ANNALS N. Y. ACAD. SCI.

fa a ie ate cet 3

ee ee ee

ri dodo dana
ie fi thf OININIS

C. eburneum

72 leet a

odds
Ve ages ah a = eee a Be a =
i pee

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Tamaya (GIN IININGE

ni gdb dud wd ede
Bala NINA

SS eS ee eS

C,ada

lubed

a a aay a a oo

ee ers eee ee ee a

e

Huu den tea
ad te a

C. album

PLP CaS

C. scabridum

ee Sap)

. eitrinum

(6,

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Va ee he ea ag Ge

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.mediterraneum

i;

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C, columna

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FREEEEEEEOWTCE

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hs

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in

7

PLATE II

Fic. 1. Vicinocerithiwm bouei (DESHAYES). X 2.
Fig. 2. Vicinocerithium parailelum sp. nov. X 2.
Fic. 3. Cerithiwm adansoni BRUGUIERE, a young individual. 14
Iie. 4. Cerithium tuberosum CoLUMN2%. X 14.
Vig. 5. Cerithium wquispirale sp. nov. X 2.
Fie. 6. Cerithiuwm retardatum sp. nov. X 2.
Vie. 7. Cerithium bicarinatum mut. trispiralis mut. nov. X 2.
Fig. 8. Cerithium bicarinatum DESHAYES. X 2.
The figures are from photographs, retouched by the author.

aS,

ig x so at stovigri a sun's nano

stodtgn ot wt bodouorer starsat a om mona

eA 7 hig

VotumE XX, Puate Il.

Annats N. Y. Acap. Sct.

—

PLATE III

ONTOGENY OF SIX SPECIES OF CERITHIUM

Numbers at the left of the plate indicate the numbers of the volutions.
Dotted lines indicate gradual transition from one volution to the next figured.

The amount of enlargement is given on the plate; actual measurement of the

portion of the shell figured is given below. All the figures on Plates III to IX

are from original drawings by the author.

Fic.
Fia.
Fie.
Fie.
Fig.
Fie.
Fig.
Fie.
Fig. 9.
Fie. 10.

AD ork WON

ies)

. Cerithium tuberosum, fourth volution. 1.6 X .8mm.

. Cerithium adansoni, protoconch. .6 X .4mm.

. Cerithium adansoni, second volution. .8 * .3mm.

. Cerithium adansoni, third volution. 1.1 X .5mm.

. Cerithium? noduloswn, fourth volution. 1.9 * 1mm.

. Pseudovertagus aluco, fourth volution. 2.2 * 1.1mm.

. Cerithium lamellosum, protoconch and first volution. .5 X .7 mm.
. Cerithium lamellosum, third volution. .7 X .82 mm.

Cerithium retardatwmn, second volution. .5 & .25 mm.
Cerithium retardatum, third volution. .75 <X .87 mm.

mW oral x
ns Pat oe Mcjrmnias 40 aaivata 212 40 reA9OKO = Resa

Sebo Sts emesis tis aba adh AB. Snake ha encanta
_ bopuatt 4290 odt of coltuioy ono aon) soittanert Innbery otacibit zonil bottom —
oid 20 Jusmoreao (sirdon joule of) co novi »t isinomtAlas Yo Janome oT
Xt of IIT astat't no vena ent i “wotod noviy ai bosmgit (lode adt Yo motrroq
tar ym Ear pate loabamboaiia ies: clube virage ci

: se La Gis, Cem 5 sur tr ania aio Ch,
oe ort BX LL roitatoy Hrlds Angas sw19d ae
a eae weet EX QE ols stor ee i
Fs tetas EEX SS .cottslor drtwot |,oos |

poy gia eK 8 " saoftatoy tah hag Mouovotorg

Bhs eA, eis hi wilh RaRLOR BEE Oe -oltsloy, hridt mle tin & ort
Meh 4s - meer SS. G. stttTTOT baooss soutien muibdihed. 2 cee
oe omer 38. x BT. aottutor batt atin uc

pe}
= ft
4 § n
ies] x x
a
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=)
i)
- a oeerrrrrrr*-:
K —
K
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a
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ie)
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2
x
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Kn
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4 x x
N oO 2 SSS
7
3)
nm
a
4
v ee AR et ee es ee, oo ee oe oe eg mg
4
al
A
n
|
2
S| = EN a) vr

retardatum

ce

C.lamellosum

C 2? nodulostum P aluco

adansoni

[<;

C tuberosum

V

pao
re

ae
a

i
5
rs it sare A

PLATE IV e

ONTOGENY OF SIX SPECIES OF CERITHIUM (continued)

. Cerithium tuberosum, eighth volution. 4.6 «* 2.2 mm.
. Cerithium adansoni, fifth volution. 3.5 * 1.5 mm.

Cerithium adansoni, eighth volution. 9 * 3.4mm. raise?

. Cerithium? nodulosum, sixth volution. 6 * 3 mm.

Cerithium? nodulosum, eighth volution. 6x 5mm. Later whorls of
this shell are not figured, as they are too large to show details when
reduced to the scale of this plate.

. Pseudovertagus aluco, seventh volution. 5.2 * 2.3 mm.

Pseudovertagus aluco, eighth volution. 7 X 3mm.
Cerithium lamellosum, fifth volution. 1.2 * .6 mm.
Cerithium retardatum, fifth volution. 1.2 « .6mm.
Cerithiwm retardatum, seventh volution. 2X 1mm.

VI OTALT

f .

(beuaisno9) vésrserrtiee YO Baad a 10° ‘eso0rn9 dhs

Det Pecan set 2X BA “oitator dtdgio pee sauiaries . ott
CS RD ea ‘urd XBL doituloy ASF inossndy worded Le ort
3 ner MERE A .coidntoy sttgio Awoaunbn swwiiliis9, 8 .orH 4
EN . sa 8 XD eile Winksk: peictatlls Yesulatoes aan

Yo also sot ima XO .nottyfor Wiigio swweoluhow Corio vt
‘ > aeidw eltated,wode of ogtal-oo} orn yodd an bowrait tom ats Mode add eat
2 eit a ,; . dtalq Aidt 10 olsoe ot ob Dooubor .
m : ore B.S x Ss _Moituloy Misnsree, oom anqotrooobiras | Oo ont Saar

ae ie HH oe umn & XT Mois ulor dtigio .oowly aypnovobuaed 0. pices

eee,

Tite WAR a ni. x St oiinloy At swyaoitonwns NTN 2 ord
$5 “somitt 8. XS. srotsulor tt eas ihe wasitiyo & alll

‘

retarcdatum

VoLUMD XX, PLATE IV.
(&

x20

lamellosum

c

P. aluco

C2? nodulosum

9°

x =
ic
°
w

nN -~-em emer er er eer er er errr rer ¢
G
a)
S
Y

C tuberosum

ANNALS N, Y. AcAp. Scr.

Fie.
Fie.
Iie.
Tie.
Fic.
Fie.
Fic.
Fig.
Fig.

1D oP Ww bh ee

co ©

PLATE V

ONTOGENY OF SIX SPECIES OF CERITHIUM (continued)

. Cerithium adansoni, ninth volution. 12 X Tmm.

. Cerithium adansoni, aperture. 16 X 12mm,

. Cerithium equispirale, ninth volution. 2.5 X 1.4mm.

. Cerithium equispirale, twelfth volution. 4.4 * 8.5mm.
. Pseudovertagus aluco, tenth volution. 10 * 4.5mm.

Pseudovertagus aluco, eleventh volution. 16 X 7mm.

. Cerithium lamellosum, ninth volution. 3.4 * 1.5 mm.
. Cerithium lamellosum, eleventh volution. 6 X 3.5 mm.
. Cerithium retardatum, ninth volution. 3.8 * 1.8mm.

4 aT At

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PLATE VI

ONTOGENY OF SIX SPECIES OF CERITHIUM (continued)

. Cerithium tuberosum, thirteenth volution. 12 «* 11.5 mm.
. Cerithium tuberosum, fourteenth volution. 24 * 29 mm.

. Cerithium cequispirale, fourteenth volution. 9.5 * 9.2 mm.
. Pseudovertagus aluco, thirteenth volution. 19 * 11 mm.

. Pseudovertagus aluco, fourteenth volution. 22 * 20mm,

Cerithium lamellosum, aperture. 12 * 11 mm.

. Cerithium retardatum, fourteenth volution. 8&5 K 4mm.

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PLATE VII
ONTOGENY OF CERITHIIDZ

. Cerithium callisoma, third volution. .8 X .8mm.

. Cerithium menkei, second volution. .2 * .6mm.

. Cerithium menkei, fourth volution. 1.8 X .8mm.

. Vicinocerithium parallelum, second volution. 1.2 * .5 mm.
. Vieinocerithium parallelum, third volution. .2 * .§mm.

. Vicinocerithium bouei, fourth volution. 1.4 * .6 mm.

. Potamidopsis tricarinata, second volution. .4 * .19 mm.

. Potamidopsis tricarinata, third volution. .6 X .8mm.

. Potamidopsis trochleare, fractured protoconch. .4 X .8mm.
. Potamidopsis trochleare, fourth volution. 1X .4mm.

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PLATE VIII
ONTOGENY OF CERITHIIDA (continued)

. Cerithiwm callisoma, sixth volution. 1.8 X .8mm.

. Cerithium callisoma, eighth volution. 2.6 * 1mm.

. Cerithium menkei, fifth volution. 1.8 * 1mm.

. Vicinocerithium parallelwn, fifth volution. 2.4 * 1mm.
. Vicinocerithium parallelum, seventh volution. 8 X 2mm,
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Fig. 10. Potamidopsis trochleare, twelfth volution. 11.8 * 7.5mm.

. Vicinocerithium bouei, eighth volution. 2.8, 1.4 mm.
. Potamidopsis tricarinata, sixth volution. 1.4 * .6mm.
. Potanidopsis tricarinata, tenth volution. 2.7 X 1mm.

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PLATE IX
ONTOGENY OF CERITHIIDA (continued)

Cerithium callisoma, tenth volution. 7.3 * 7mm.

Cerithium menkei, tenth volution. 13 * 11.5 mm.
Vicinocerithium parallelum, twelfth volution. 6 * 4mm.
Vicinocerithium parallelum, aperture. 9.8 X 8 mm.
Vicinocerithium bouei, twelfth volution. 38 XK 2mm.
Vicinocerithium bouei, aperture. 8.5 * 6.5mm.

Potamidopsis tricarinata, twenty-third volution. 12 * 5mm.
Potamidopsis tricarinata, twenty-fourth volution. 19 * 11mm.
Potamidopsis trochleare, aperture. 11.8 X 7.5 mm.

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