‘OBSERVATIONS ON
| i j ebay = ea 3 +

a 2 ‘ “ a ts ey te ee

GASTEROPODS OF NEW ENGLAND

S. ans Fie,

+ n : x fi &

_ PEABODY MUSEUM
oi, ; Salem, Massachusetts

OBSERVATIONS ON

LIVING GASTEROPODS OF NEW ENGLAND

By EDWARD S. MORSE

Xt SONlan
aw A)
>

Insti :
‘Wt,
7)

U/
onal Museu:

_ PEABODY MUSEUM
Salem, Massachusetts

1921

PRINTED BY
The Nichols Press

113 MARKET STREET, LYNN, MASS.

OBSERVATIONS ON LIVING GASTEROPODS
OF NEW ENGLAND

By EDWARD S. MORSE

In 1919 I published my ‘“‘Observations on Living Lamellibranchs
of New England,’’ in the ‘‘ Proceedings of the Boston Society of Natural
History,” (Vol. XXXV, No. 5). Forty-eight species were described
and figured, the protoconchs of nineteen species were also given and a
number of the expanded animals were portrayed for the first time.
Other species that had been very inadequately figured were drawn;
among these were Turtonia minuta, Liocardium mortoni, Gemma
gemma, Cumingia tellinoides, Mactra lateralis, Ceronia arctica and
Pholas truncata; still other species had been figured by FORBES and
HANLEY but, as stated in my “Lamellibranchs,” on so small a scale and
so imperfectly drawn as to be of little value. Liocardium mortoni had
also been figured but it bore no resemblance to the expanded animal.
At this point I must call attention to the exquisite drawings in color
by Mr. J. HENRY BLAKE, of twenty-three species of New England
mollusks made to illustrate the beautiful collection of New England
shells brought together by Mr. C. W. JOHNSON, Custodian of the
Boston Society of Natural History, and exhibited in its Museum.
Mr. Dwicut BLANEY has made a number of drawings with notes and
descriptions of mollusca dredged in Frenchman's Bay, Maine. These
drawings are very fine and many of them are of species I have not
seen alive. It is hoped that he will prepare this material for pub-
lication.

It should have been stated in my “‘Lamellibranchs”’ as an excuse
for the imperfection of many figures and paucity of description that

1

some of the work might properly be regarded as bi-products as during
my studies of the Brachiopoda in Eastport, Maine, a number of species
of mollusks came under my vision and I could not refrain from drawing
them. In this communication some of the descriptions were made
under the same conditions.

In the ‘“‘Lamellibranch”’ paper a few introductory pages were
devoted to a protest against the recent multiplication of generic names
and abandonment of many generic names that had been familiar to
students for nearly a century. I quoted a number of authorities who
had uttered emphatic protests against this growing evil. Many others
might have been quoted. Pror. F. B. SUMNER, in “‘Science,’’ June
18, 1915, in an article entitled, ““Some Reasons for Saving the Genus,”’
vigorously attacks the taxonomists. His illustrations are cogent and
convincing. He says, “Returning to the subject of generic names, it
must not be supposed that the only evil resulting from this progressive
‘splitting’.1is the mere inconvenience of our having to learn new names
as fast as the old ones are displaced by accredited authorities. This,
indeed, is bad enough, but there is an even more harmful result which,
I think, deserves further emphasis. I have spoken above of generic
names as verbal clues to the nearer kinships between species. These
clues lose their value in proportion as genera are made less and less
inclusive.” Dr. HAROLD S. COLTON, in “Science,” September 3,
1915, not only heartily approves of PROF. SUMNER’S article but gives
another reason for saving the genus. He says, “‘I am sure he has the
sympathy of the great mass of workers in non-taxonomic biology.”’
He further says, “‘This whole discussion hangs on the question, is it
necessary to change generic names to advance our knowledge? The
writer believes that to change generic names without an overwhelming
amount of evidence in favor of the change is hindering instead of
advancing science.”’ That the feeling is bitter among zoologists is
indicated by the following extract from a letter of a professor of zoology
in Harvard. “I fervently add an Amen to your sermon at the begin-
ning of the ‘Lamellibranchs’ and I can’t tell you what a delight it was
to open its pages and meet the good old names: Modiola modiolus, M.

a

plicatula, Solen ensis, Machera costata and Mya arenaria; all the old
girls as I first knew them around Nahant when I got introduced to
them. The new names make me think of the divorce court. They
seem to all have been swapping partners.”’

Unless we return to a sane method of using names, going back
to the Linnaean conception of generic distinctions when it does not
conflict with obvious inaccuracies there will continue three catagories
of nomenclature. First, and by far the most ancient are the vulgar
or vernacular names when they exist; though formerly considered
the most unreliable, in the present debauch of names, they are regarded
by many workers as more reliable. Second, the names founded on
generic principles as they have existed for nearly a century, familiar
to all students and the only names known to geologists, paleontologists
and other students of cognate subjects and third, the modern incubus
of names which have been imposed by taxonomists, — a bewildering
accession that paleontologists cannot keep up with arid do not. In my
“Lamellibranchs”’ I gave my reasons for adopting the names given in
the second edition of GOuULD’s “Invertebrata”’ and generally in the
three great standard works of FORBES and HANLEY’s “British
Mollusca,” 4 Vols., JEFFREYS’ “British Conchology,’’ 6 Vols., and
Woopwarp’s “Manual”. In this same paper some errors crept in.
I made some mistakes in the Mytilide. My attention was also called
to Pandora trilineata which should have been indicated as P. gouldiana,
of DALL. This distinguished malacologist has shown that the true
P. trilineata, of SAy, is clearly distinct from the northern species to
which DALL gave the name gouldiana. An examination of the south-
ern species show that in form, size, shape of shell, and particularly of
the hinge it is quite distinct, so differert, indeed, that one wonders
why a new generic name was not immediately established for it!

ENTALIS STRIOLATA Stimpson
Pl. I. Fig. 1. Length 48mm.

A figure is given of this creature with body extended. I have
watched it in this expanded condition and have never seen the tentacles

3

as figured by LACAZE-DUTHIERS nor the slightest signs of movement.
LACAZE-DUTHIERS, in his remarkable ‘‘Memoir of Dentalium,”’ in the
‘Annals des Sciences Naturelle,’ has given an exhaustive description
of the organization and development of Dentalium. Relations are
pointed out showing that its affinities are with the lamellibranchs,
gasteropods and other larger and smaller groups of mollusks and
annilids. Some years ago in the “‘Proceedings of the Boston Society of
Natural History” I called attention to some curious resemblances
that Dentalium held to the Tetrabranchiate cephalopods, namely the
long retractile, thread-like tentacles, the curious cartilagenous body
surrounding the csophagus and the fact that the long shelly tube
curves dorsally as in Nautilus, Ammonite and other members of the
class.

ACMA TESTUDINALIS Muller
Pl. I. Figs2... Length 20mm.

Head broad, tentacles long, wide apart, eyes at base of tentacles
which are slightly thickened, mouth large, encircled by a membrane
which is very mobile and strongly foliated. In the “Proceedings of
the Boston Society: of Natural History,” (Vol. XXXIV, No. 8) I have
described the early stages of this species. I found no trace in the
embryonic form of a helicoid shell. Fig. 2 (A) shows attitude of the
head; (B), highly enlarged view of tentacle; (C), mouth showing
radula within.

ACMA ALVEUS Conrad
Pl. I. Fig. 3. Length 14mm.

In motion the head swings freely to the right and left, protruding
beyond the edge of the sheff, as in Fig. 3, (A). Tentacles long and
wide apart. Fig. 3, (B) another view of head.

CREPIDULA FORNICATA Linn
Pl. I]. Fig. 4. Length 38 mm.

Head bi-lobed, deeply cleft, lobes long and oval; tentacles thick,
not pointed, eyes on thickened base; foot oval, anterior face rounded

t

and auricular. The protoconch (Fig. 4, A, Pl. VIII) shows very clearly
its conversion from a coiled shell to the broad, pan-like shell of the
adult. At this early stage the shell resembles that of an adult S7gare-
tus. Then the mantle pours out from its entire margin lines of accre-
tion, the columella of the early shell forming the base of the so-called
seat of the adult form.

CREPIDULA PLANA Say
Pl. II. Fig.5. Length 32mm.

Head bi-lobed, lobes slightly rounded; foot square in front, sides
parallel, rounded behind; tentacles pointed, eyes on prominent bases.

CREPIDULA CONVEXA Say
Pl. II. Fig. 6. Length 10mm.

Head bi-lobed, lobes long; foot rounded, sharply auriculate;
tentacles long and blunt. The resemblance of the soft parts of the
three species of Crepidula to Crucibulum striatum is very marked. In
the latter species the lobes of the bifurcated head are larger than in
Crepidula. Figs. 5 (A) and 6 (A) Pl. 8, are believed to be the early
stages of C. plana and convexa. A curious wedge shaped process comes
in between the first coil of the shell and the upper part of the body
whorl in C. fornicata and plana; 1 did not observe it in C. convexa.

CRUCIBULUM STRIATUM Say
Pl. II. Fig. 7. Length 22mm.

This genus known as Calyptrea in FORBES and HANLEY, JEFFREYS,
and in the first edition of GOULD’s “Invertebrata,” is not an uncommon
shell along the coast. Our shell is closely related to the English
species though the ‘figure given of the English form of the animal
differs from the one here represented. The head is strongly bi-lobed,
the tentacles are thick and stout with enlargements at their bases on
the outside of which are the eyes. The foot varies in form, rounded

anteriorly (Fig. 7 B) and, at times, elongate with rounded anterior
margin and sharply expanded sides (Fig. 7 C). On the right
side a collar arises surrounding the head, on the left a hood from
which the eggs arise. The eggs are in clusters numbering seven.
(Fig. 7 B). These clusters surround the head. The young shell
(Fig. 7 A) resembles the shell of Velutina levigata as noted by JEFFREYS.
The creature devoured greedily fragments of Yoldia limatula and
when teased with a scalpel snapped at it in a vicious manner.

CEMORIA NOACHINA Linn
Pl. I]. Fig. 8. Length 5mm.

The figure of this species in FORBES and HANLEY under the name
of Puncturella noachina shows some differences from our species.
The shell is represented as standing much lower, the foot hardly clears
the lower margin of the shell. The head tentacles are represented as
much longer and pointed, the lateral tentacles are seven in number
increasing slightly in length to the last one, while in our species the
next to the last one is twice the length of theothers. The foot is much
narrower in our species and the edge is sharply indented and irregular.
(Pl. II. Fig. 8 A). JEFFREYS figures the English species with ten
lateral tentacles on a side, the penultimate one larger than the rest.
These differences may be regarded as varietal only.

In the early stage of Cemoria (Pl. VIII Fig. 8,) the shell resembles
a Srgaretus and then suddenly appears the close rib-like growth of
the adult form. The growth is much more rapid anteriorly so that
the nepionic shell stands almost vertical in relation to the marginal
line.

MARGARITA UNDULATA Sowerby
Pl. IJ. Fig. 9. Diameter 11 mm.

This species is undoubtedly the Trochus groenlandica of Chem-
nitz, as given by JOHNSON in his list of the Mollusca of New England,
but, following GOULD, I retain the old name. FORBES and HANLEY
quoting ALDER, say that the animal is white or yellowish white, also,

6

that in the English species there are five lateral tentacles arranged in
two series, three in the region of the operculum, two anteriorly placed
with a distinct interspace between. In our species the lateral ten-
tacles are six in number equidistant, the anterior ones slightly longer,
diminishing in length posteriorly. (Pl. II, Fig. 9 A) marginal ten-
tacles enlarged.

MARGARITA HELICINA Phipps
Jel, aul Fig. 10. Diameter 6 mm.

This exquisite shell is usually found on the large lamanaria in
March. Its perfect symmetry and beautiful purple iridescent surface
easily render it one of our most attractive shells. It is a common shell
in Iceland, Spitzbergen, Scandinavia and Northern regions of Great
Britain. In collecting numbers of specimens one quickly recognizes
two forms; a large globular form and a smaller depressed shell with
flaring aperture. This form I described many years ago under the
name of Margarita campanulata, supposing it to be a new species.
In studying large numbers collected at Ironbound Island, Maine, I
am convinced that the campanulate form represents the male of the
species. FORBES and HANLEY detected this form among specimens
. of Margarita helicina. In their classical work they say ‘‘There are
two forms of this shell so apparently distinct at the first glance that we
hesitate to regard them as belonging to the same species. The one is
peculiarly oblique and depressed, a very expanded outer lip and the
rest of its features modified to correspond with the general contour;
the other is far more globular.’”’ In our species the muzzle is deeply
crenated, the ends strongly ciliated (Fig. 10 A). The eyes are
pedunculated and on the inside, at the base of each tentacle, is a small
tubercle. The tentacles are long and larger than the lateral tentacles,
these are. five in number becoming shorter towards the tail except the
middle one which is markedly shorter than the others. In FORBES
and HANLEY the lateral tentacles are described as being in two groups,
three in the forward group, with quite an interspace and two behind.
The animal of the English species is described as orange color, while

7

in our form the female is orange color while the male is Naples yellow.
In the male the lateral tentacles are shorter than those of the female.
At Ironbound Island I collected all the specimens in a restricted
locality and found 220 females and 164 males. JEFFREYS, in his
‘British Conchology,”’ describes the creature as having six tentacles
on a side. Despite these slight differences they may be regarded as
geographical variations. The early stages of the shell resemble so
strongly Vztrinella that some of the species described as Vitrinella
from the West Coast and other regions may turn out to be the young
of some species of Margarita (P. VIII. Fig. 10 B.)

TROCHUS OCCIDENTALIS Migh-Adams
Pl. IJ. Fig. 11. Diameter 12mm.

This beautiful species is a rare form on our coast, it is also very
rare in England, according to FORBES and HANLEY, through JEFFREYS
says it is not uncommon in some places. FORBES and HANLEY identify
this shell as the 7. alabastrum, and places occidentalis among the
synonyms, adding, however, that ‘should it prove the Trochus occi-
dentalis of North America, as judging from the description, we think
likely enough, that name must be substituted for Beck’s.”” JEFFREYS
(1865) recognizes T. alabastrum as T. occidentalis, and DR. G. O.
SARS, in his fine work entitled “Mollusca Regionis Arctic Norvegie,”’
published in 1878, recognizes T. alabastrum, of BECK, as T. occidentalis,
of MIGHELS. The English form as described by FORBES and HANLEY
differs somewhat from our form. The animal is described as “entirely
pure white,’ while our species is yellowish white, mottled with brown-
ish granules, the creeping disk orange. T. alabastrum, according to
FORBES and HANLEY, has three lateral tentacles on a side. JEFFREYS
says, ““appendages three (sometimes four) on each side, resembling the
tentacles in every respect except in being smaller.’”’ The few speci-
mens of 7. occidentalis that I was able to observe had four tentacles
on a side.

The shell of 7. alabastrum of England and Norway very closely
resembles the 7. occidentalis of our coast. The revolving ribs are

8

much larger and sharper in the English species. If these variations
with the differences in color and the three lateral tentacles instead of
four constitute good specific differences, then the name alabastrum
should be retained. I think, however, these differences should be
_ considered geographical variations.

SKENEA PLANORBIS Fabricius
Pl. III. Fig. 12. Diameter 2mm.

This is next to the smallest gasteropod on our coast, the smallest
being Homalogyra atomus, which I discovered at Hampton beach and
which afterwards was found in Rhode Island, by Miss M. W. Brooks,
recorded in the “Nautilus,” (Vol. XXIII, No. 6). The animal of
Skenea is very active and bold. It is found under stones between
high and low water mark and also on sea weeds. Accustomed as it
is to the thrashing about of the weeds by the dashing waves it becomes
hardened to buffiting and hence its bold behavior. It is found on
both sides the Atlantic. The animal is brownish in color. FORBES
and HANLEY describe the English species as hyaline white. The shell
figured by them is certainly larger than that of the American species.
In our species the shell is carried erect as in the figure and not resting
flatways as described by JEFFREYS. Further comparisons may show
that our species is different from the European one.

RISSOA MINUTA Totten
Pl. III. Fig. 13. Length 4mm.

PROFESSOR CLEVELAND, of Cornell, long since dead. collected this
species in the Charles River estuary in great numbers and soon detected
a form somewhat more globose which he considered another species
and intended to describe it under the name of Rissoa pigmenta. When
he told me that he noticed a marked difference in the odor of the
two forms I realized that the difference was sexual, and the form was
probably that of the female of the species. It is strongly pigmented,
the pigmentation being the result of some minute alge growing on the

9

shell. The foot is oval, dilated into wings in front; the muzzle is long,
narrow and bifurcated. The animal is brown or blackish and is very

active.

LACUNA VINCTA Montagu
Pl. III. Fig. 14. Length 12mm.

To get an idea of the great number of names that this creature is
burdened with one must consult FORBES and HANLEyY who include
these names in their great work. Especially must the student refer to
JEFFREYS, (Vol. III) who records L. vincta as a synonym of L. divari-
cata of Fabricius. SARS also recognizes it under the name divaricata
and gives an excellent figure of it which certainly closely resembles
our form. Our species has a brown variety, known as L. fusca. The
animal of L. vincta is nearly black above, the foot light gray, the
head very broad, the tentacles long, the eyes far apart on their outer
bases. The black of the head terminates abruptly at the base of the
tentacles just below the eyes, the tentacles are very light colored.
The creature is very active; the shell is held vertically and ossilates
continually when the creature is crawling. The young shell has a
very short spire. (Pl. VIII. Fig. 14 A).

LACUNA NERITOIDEA Gould
PET Biew5s engthesmnam

This species is regarded as a variety of the English species L.
pallidula by JEFFREYS and Sars. The animal is yellowish, the eyes
prominent on thickened bases from which spring the rather long
tentacles, the muzzle is short and truncate with angular process above.
The opercular appendages are very short. In Portland, Maine, the
species was ovulating in March and individuals were very abundant.
The drawing here given was made sixty-five years ago. I am amazed
that a new generic name has not been given to the species. The shell
closely resembles a short spiral Litorina, the animal, however, with
its opercular tentacles, and the shell with its lacunal columella is
unmistakable.

10

SCALARIA GROENLANDICA Chemn
Pl. III. Fig. 16. Length 25 mm.

The animal is white and somewhat translucent, mottled with
opaque white. The foot is long, rounded behind and broad and
truncate in front. JEFFREYS says of the English species, S. clathratus,
‘‘the body is clear white and thickly interspersed with Opaque white
flakes, foot often carried considerably in advance of the head and
tentacles.” resembling in these respects S. groenlandica. The oper-
culum of the English species is described as white by CLARK while
JEFFREYS says it is yellowish brown. In the other English species of
Scalaria the operculum is described in two of them as dark horn color,
in another species light horn color. In our species the operculum is
quite black forming a striking contrast to the white shell and white
soft parts. Mr. BLANEY says that a deep purple fluid is secreted
by the animal on its removal from the shell.

The early stage of this species shows for nearly four whorls a
smooth shell resembling a full grown Rissoa minuta, then abruptly
begins a series of costee so characteristic of Scalaria. (Pl. VIII. Fig.
16 A).

TURRITELLA EROSA Couthouy
PL. III. Fig. 17. Length 20mm.

The foot is white, the proboscis lemon-yellow, the end is deeply
cleft and each lobe moves alternately as in Aporrhais. The crawling
disk appeared nearly circular in outline about the size of the aperture
of the shell, deeply wrinkled with the anterior portion widely rounded
and shouldered at sides. I did not see it fully expanded. The creature
was very sensitive, it protruded with extreme caution. The ten-
tacles were rather short and delicate, the eyes on slight prominences.

_ JEFFREYS regards the English representative of this species as
Turritella polaris of BECK. FORBES and HANLEY describe the foot
as very short in proportion to the body, truncate in front, rounded
behind. FORBES and HANLEY figures the animal of 7. terebra in an
expanded condition. In England T. erosa is found fossil in the glacial
deposits.

11

APORRHAIS OCCIDENTALIS Beck

Pl. III. Fig. 18. Length 57 mm.

This curious shell with its long turrited spire and expanded outer
lip like Strombus, combines a number of diverse characters that have
puzzled systematists. It has a long, cylindrical body, a prominent
head with long, thick muzzle, bifurcated, (Fig. 18, A) a strong, sturdy
foot stalk terminating in a rather short, narrow creeping disk which
throws itself into curious contortions. At its extreme end it supports
a long, narrow slightly curved operculum which overhangs both sides
of the foot. The creeping disk is irregular in shape, deeply wrinkled,
wider in front and tapering to a point behind. Near the end beneath
is a thick blunt process (Fig. 18 B) springing from the left side and
extending obliquely across the foot, an appendage, so far as I know,
unique in gasteropods; its function is enigmatical. The foot is pure
white, the rest of the body is tinged with yellow. The mantle extends
to the margin of the aperture. The tentacles are long and very thick
at the base, the eyes are prominent and supported on a thickened
projection at the base of the tentacles (Fig. 18, C). The tentacles
are brownish in color on the dorsal surface, in life they were incessantly
swinging aimlessly, the long proboscis is strongly bifurcated and the
movements which were constant were alternating. (Fig. 18, D).
Turritella erosa has an identical form of proboscis moving also in the
same alternating manner. There is a resemblance to Aporrhais pes-
pelicant in the lingual dentition of 7. erosa.

The specimen studied was sent to me by DR. HAROLD S. COLTON
from the coast of Maine. Dr. COLTON had had it in captivity for
four days. He said it had been very active in confinement, crawling .
about the pan and up its sides and dropping off with a thud to the
bottom. It proved a very interesting captive. Despite its transporta-
tion in wet sea weed by mail for over three hundred miles it had lost
none of its vitality, and in its contortions the claw-shaped operculum
functioned evidently as an organ of locomotion, recalling the behavior
of Strombus to which genus Linnaeus first assigned it.

i

The English species, Aporrhais pes-pelicani, has the outer lip
expanded in two pointed projections and the shell is strongly tuber-
culated. The animal in shape is not unlike that of A. occidentalis,
the color, however, is quite different. FORBES and HANLEY, quoting
JOHNSON, state that “It is of a general yellowish-white hue, the ten-
tacula mingled yellow and scarlet; the snout and head thickly speckled
with scarlet, markings of which color are more sparingly distributed
on the paler body and sides of the foot; sometimes they are not present.
We have always found it very sluggish and unwilling to display
itself when captured.” JEFFREYS says “It is shy, slow and awkward
in its movements.”’ In these habits it is very different from the
American species, which is extremely active, as above described.
As no mention is made, in the English species, of the curious appendage
on the ventral side of the foot posteriorly, which had it occurred would
certainly have been observed indicates that the two forms are widely

different.

TURBONILLA NIVEA Stimpson
PI.III. Fig. 19. Length 7 mm.
The muzzle is rather long, narrow at its base and roundly bifur-
cated in front. The tentacles are short and round at their tips. The
eyes are on the inner base of the tentacles and rather close together.

MENESTHO ALBULA Moller
Pl. III. Fig. 20. Length 14mm.

The animal is uniformly white, mottled with opaque white gran-
ules, the foot broad and square in front, extending some way beyond
the muzzle which is broad and short. Tentacles with eyes at their
outer bases on slight swellings. On the upper anterior surface of the
foot are two rounded areas of white granules closely crowded.

VELUTINA LAVIGATA Lin
PI.IV. Fig. 21. Length 8 mm.

The eyes are much closer together than in V. zonata, short and
obtuse, head with marked projection between the tentacles. The

13

genitalia projecting from the right side is globular in shape with a
curious claw-like process on one side (Fig. 21, A).

VELUTINA ZONATA Gould
Pl. IV. Fig. 22. Length 12mm.

Head broad, tentacles wide apart, not pointed, eyes on distinct
shoulders. Body translucent white, mottled with opaque white
spots, tentacles strongly mottled. Mr. DwiGHT BLANEY has figured
a specimen of this species with a double eye on the right side.

LAMELLARIA PERSPICUA Lin
Pl. IV. Fig. 23. Length 12mm.

The only sketch I had of this creature shows it from below. The
foot has an irregular indented margin. Mr. DWIGHT BLANEY has
some remarkable drawings of this species which, I trust, he will soon
publish.

NATICA HEROS Say
P].1V. Fig. 24. Length 60mm.

The animal is more elongate than that of N. duplicata. Its color
is light gray, the tentacles are light grayish in front, darker behind,
very broad and flattened at the base and tapering to a point; a sharp
angular depression is seen at the base of the tentacles. The foot
below is yellowish. The propodium forms a sloping shield resting
against the shell, it is closely wrinkled and a beautiful mouse-gray.
The left side of the propodium is developed into a large, round ear-
like opening into which the water may be seen pouring constantly, a
veritable syphon, in fact. This syphon may be directed forward or
backward. When the proboscis is extended the propodium is sharply
cleft to make room for it, as shown in Fig. 24, (A). The protoconch
is shown in Fig. 24, (B), Pl. IX. The protoconch presents in general
outline that of the adult, the proportions, however, are widely differ-

14

ent, as shown in figure 24, (C), Pl. IX. This drawing is reduced,
from a Natica heros, 80 mm in length, to correspond in size to that
of the protoconch which is only %mm. in length.

NATICA TRISERIATA Say
PI. IV. Fig. 25. Length 16mm.

This creature moves rapidly and has the power of crawling on
the under surface of the water. The tentacles are wide apart, flattened
transversely, broad at their bases, long and pointed, bordered with
black on each side with a light interspace in the middle. (Fig. 25 A)
tentacles enlarged.

NATICA CLAUSA Brod and Sow
P]. IV. Fig. 26. Length 15 mm.

The animal differs in no important respect from the other species
of Natica. The propodium assumes in form an irregular rhomboidal
shield in front. The foot does not reach quite so far back as in Natica
triseriata. A sketch of a young Natica heros resembles that of Natica
clausa except that the tentacles do not appear so wide apart. The
color of the entire animal is a delicate purplish tint.

NATICA IMMACULATA Totten
PI. IV. Fig. 27. Length 8mm.
The animal is white; elements of the foot expanded as in other
Naticas. The only observation that I made was that the syphonal
fold was large.

NATICA DUPLICATA Say
PI. IV. Fig. 28. Length 50 mm.

The extraordinary character of the foot with its three divisions
of propodium, mesopodium and metapodium fully developed and
these lobes absorbing sea water like a sponge renders it extremely
difficult to secure a normal outline of the parts. I have many sketches

15

of this species and Natica heros and they all vary in their outlines.
Living almost completely immersed in the sand they plough ahead
leaving a long, sinuous track on the beach. The individual shows no
timidity and if one places his finger in the track of the animal the
creature pushes strongly against it; accustomed as it is to push against
pebbles and other objects buried in the sand it does this without
alarm. The creature is very sluggish in its movements and three
hours were consumed in attaining full expansion. The anterior por-
tion of the foot formed a broad, sloping shield, in color and wrinkles
closely resembling the pileus of the common edible mushroom. The
creature is yellowish fawn, the propodium darker and the outside edge
very dark colored. The tentacles are widely separated, short, broad,
at base, flattened and curved outward, they are usually closely
appressed against the shell and partially concealed by the propodium,
as in all Naticas thus far examined; rarely are the tentacles seen free.
The curious fold of the foot on the left side as seen in Natica heros was
not seen in Natica duplicata. This fold represents a rudimentary
syphon.

BELA DECUSSATA Couthouy
PI.IV. Fig. 29. Length 10 mm.

The animal is nearly transparent with minute white dots marking
its surface. The foot is long, narrow, truncate in front, its anterior
margin finely wrinkled; tentacles capable of considerable expansion,
wide apart; eyes third way down from tip of tentacles. JEFFREYS’
figure of this species shows shorter tentacles with eyes half way up.
He says ‘‘American specimens are much smaller than ours as is also
the case with Purpura lapillus and Buccinum undatum.”

COLUMBELLA LUNATA Say
Pl. V. Fig. 30. Length 5 mm.

Foot long, narrow, tapering behind; tentacles short, blunt,
thickened, meeting at their bases, eyes at thickened base. Foot pro-

16

jecting far beyond the head; head black; body marked with blotches
of grayish black. Syphon, long, encircled with black blotches. In
crawling the syphon extends anteriorly.

COLUMBELLA AVARA Say
Pl. V. Fig. 31. Length 15mm.

The soft parts resemble C. /unata in color and markings. Fig. 31
(A), and (B), head. (C.) operculum.

NASSA OBSOLETA Say
Pl. V. Fig. 32.- Length 18 mm.

Body nearly white, mottled with soot-colored spots. Foot broad
in front, diverging at each corner in sharply defined processes, recurved,
distinctly indented in median line. Syphon long, recurved. Tenta-
cles short, wide apart, eyes on prominent thickening at base of tenta-
cles. The proboscis can be greatly extended and in figure 32 (A), the
proboscis is shown widely extended, recurved and feeding on the sur-
face of the shell.

NASSA TRIVITTATA Say
Pl. V. Fig. 33. Length 18 mm.

An extremely active creature in confinement leaping by a series
of rapid somersaults, jumping at least four inches in a snapping way
using the shell as a fulcrum. The foot becomes very long and narrow
in jumping; the front of the foot is expanded on each side into long,
narrow recurved points. The tentacles are long and sharp and at
times stretched out in a straight line transverse to the longitudinal
axis of the body, as in figure 33 (A). The two caudal appendages are
long and wide apart.

BUCCINUM UNDATUM Lin
Pl. V. Fig. 34. Length 75 mm.

Foot broad, its anterior portion thrown into a number of folds in
crawling. Body and syphon marked by irregular blotches of black;

if

head slightly notched in front; tentacles wide apart; eyes at base of
tentacles on thickened shoulder; syphon long and recurved.

BUCCINUM CINEREUM Say
Pl. V. Fig. 35. Length 25 mm.

This shell is found along the entire coast. It is more abundant
south of Cape Cod; north of the Cape it is found in restricted localities.
A colony has been found in the Gulf of St. Lawrence. The northern
form has a shorter shell. The tentacles are very long, nearly meeting
at their bases, they are thickened half way up where the eyes are
placed, beyond this the tentacles become attenuated and pointed.
The body is cream-colored, dotted with light drab above, the creeping
disk is yellow. The creature is sluggish in movement.

FUSUS ISLANDICUS Gemlin
Pl. V. Fig. 36. Length 70 mm.

Foot very wide, squared in front, rounded at sides, slightly rounded
behind; yellowish white, head broad, tentacles wide apart, eyes on
prominent thickenings near base. In crawling the head and neck are
freely separated and project beyond the foot.

FUSUS PYGMAUS Gould
Pl. Vi. - Fig. 37. Length 24mm.

The shell follows the outline of F. islandicus but is diminutive
in size, a full-grown specimen measuring 7-8 of an inch in length.
There are minor differences between it and its giant relative, as pointed
out by GouLD. The animal is pure white with black mottlings as in
B. undatum. The foot is long and narrow, truncate in front, rounded
behind. FORBES and HANLEy figure the animal of Fusus propinquus
and compare it with F. pygmexus. In F. propinquus the tentacles
are shown united at their bases whereas in F. pygmeus they are wide
apart. JEFFREYS regards F. pygmexus as a variety of F. islandicus
and says “‘It seems to bear the same relation to F. propinquus as

18

F. islandicus does to F. gracilis.’ FORBES and HANLEY describe the
egg capsules of F. norvegicus as being found in odd valves of Cardium
echinatum. JEFFREYS describes the egg capsules of F. norvegicus as
compressed hemispheres each holding from two to four embryos.
Capsules of F. propinquus are attached to odd bivalves. I have found
the capsules of F. pygmeus attached to the inside of a shell of Cardita
borealis. Each capsule contained five embryos.

FUSUS DECEMCOSTATUS Say
Pl. VI. Fig. 38. Length 75mm.

Body whitish, slightly mottled with black, mottling thicker near
opercular lobe; tentacles very short and wide apart, base of tentacles
thickened, supporting eyes.

TROPHON CLATHRATUS Lin
Pl. VI. Fig. 39. Length 14mm.

The tentacles are long, united at their bases and for 2-3 their
length are thickened supporting the eyes, beyond attenuated. The
animal is uniformly white. The creature is active but not timid.

BUSYCON CANALICULATUM Say
Pl. VI. Fig. 40 Length 150 mm.

Body deeply maculated with black and slate colored blotches,
tentacles wide apart, long and stout, pointed at their ends, maculated
like the body, tips black, eyes on thickened base at lower third of
tentacles. Foot broad, rounded in front, strongly auriculated.
Ovulating September 7. In ovulating the creature was retracted
within the shell, the egg capsules issuing between the edge of the
operculum and the outer edge of the aperture (Fig. 40, A, Pl. VII). Figure
40, (B), Pl. VII, shows the appearance of the proximal end of the
string of capsules. The creature first secretes in the mud a broad
firm base and rough irregular beginning of the string as an anchor,
these strings float vertically and mixed with the forest of eel grass

19

would easily be mistaken for some kind of weed. The protoconch
(Fig. 40, C, Pl. IX) from the bulbous nucleus rapidly assumes the
shouldered body whorl, the syphonal tube is very short as compared —
with the adult.

RANELLA CAUDATA Say
Pl. VII. Fig. 41. Length 24mm. .

This shell recognized by THOMAS Say, in 1822, as belonging to
the genus Ranella was very properly recognized by VERRILL as coming
under the genus Eupleura of H. and A. ADAMS. A comparison of the
animal with that of Murex erinaceus, of England, as given by JEF-
FREYS shows similar features of color, small tentacles, etc. The
color of the foot is light yellow, the head and tentacles are white.
The foot has great powers of extention anteriorly (Fig. 41, A).

The species has never effected a lodgment north of Cape Cod.
It extends from the southern shores of Cape Cod along the entire
coast to the Gulf of Mexico.

TRICHOTROPIS BOREALIS Sowerby
Pl. VII. Fig. 42. Length 15 mm.

The animal is whitish in color, muzzle deeply notched, tentacles
rather short and blunt, the lower third slightly enlarged and thick-
ened, supporting the eyes. The English representative is described
as having rather long and tapering tentacles and muzzle elongate,
pointed at the end and deeply split. My drawing was made from a
specimen only partially expanded.

The nucleus for one whorl is smooth with slight revolving stria-
tions and then appear fine revolving ribs. The outer margin of the
aperture was broken, as shown in the figure, 42 (A), Pl. IX.

ADMETE VIRIDULA Fabricius
Pl. VII. Fig. 43. Length 13 mm.

The tentacles are rather short and blunt, slightly apart at their
bases, eyes on slight elevations at outer base of tentacles. Foot

20

square in front. The creature is an Arctic form; it is extinct in the
English seas, though formerly existing there as it occurs fossil in the
Red and Coralline crag at Sutton, England, as stated by JEFFREYS.
Further comparison should be made between the English fossil and the
New England form.

The following species, Melampus bidentatus and Alexia myosolis
though belonging to the Pulmonates, inhabit the sea shore and though
having no relation to the marine species of Gasteropods already
described are included here.

ALEXIA MYOSOTIS Drap
Pl. VII. Fig. 44. Length 7mm.

The body is white, short blunt tentacles with grayish axis, eyes
at the inner base of tentacles, head lobe sharply separated from creep-
ing disk. The creature is very sluggish in its movements.

CARYCHIUM EXIGUUM Say
Pl. VII. Fig. 45. Length 2mm.

This creature, a land snail though living in wet places, is grouped
with Alexia and Melampus and is therefore included here. The
animal is white, tentacles very short and thick, rounded at tip, trans-
parent, a line marks the junction with the body. The eyes are rhom-
boidal in shape and are situated at the median base of the tentacles
in no respect bearing any relation to Melampus and Alexia. Its
habits are apparently the same as those of the English species, C.
minimum. JEFFREYS figures the English species with bulbous ten-
tacles, like Helix, eyes on rounded supports and inside the base of the
tentacles. The shells of the English and American species are so
closely identical that the drawing in JEFFREYS’ must be entirely wrong.

MELAMPUS BIDENTATUS Say
Pl. VII. Fig. 46. Length 14jmm.

The animal is mouse-colored, tips of tentacles brown. The
tentacles are round, thick and retractile; eyes at inner base of tenta-

a1

ales. The foot is divided into three portions, the anterior portion
slightly wider than the other sections, rounded in front and strongly
auriculated, the middle section slightly larger than the other sections,
rounded in front and sides, the last division longer and narrower than
the others and rounded posteriorly. Whether these divisions repre-
sent the propodium, mesopodium and metopodium respectively I do
not know. FORBES and HANLEY say in regard to the English species,
“The foot is sulcated across the centre so as to form two creeping
disks.”” These authors describe the animal as creamy white. It has
been stated that in the Melampidz the protoconch is reversed. Plate
IX, Figure 46 shows the young shell of Melampus bidentatus and the
nucleus while somewhat oblique has a dextral turn of the spire at the
outset, as shown in Pl. IX, Fig. 46 A.

On Plates VIII and IX are collected together the figures of the
shells of the early stages of thirteen species referred to in the text.
On the lower part of Plate IX are figured the young of three species of
which the soft parts of the adult form I have not secured. Figure 47,
Plate IX is probably that of Diaphana debilis. It illustrates very
clearly the transference of the sinistral nucleus into the final dextral
form of the shell. The planorbular reversed nucleus is also clearly
shown in Figure 47 (A). In Figure 48, Plate IX is given the early
stage of some species of Philine. The reversed nucleus is nearly
upside down, the lines of growth shows its methods of transference
into the dextral shell. Vermetus lumbricalis, (Figure 49, Plate IX)
shows two whorls of the protoconch perfectly smooth and then begins
the sharply carinated ribs which mark the adult shell.

22

APPENDIX

In my paper on “Living Lamellibranchs of New England”’ I pro-
tested strongly against the multiplication of generic names and quoted
eminent authorities to show that my attitude was justified. Among
these authorities quoted were DR. CHARLES SEDGWICK MINOT, FRAN-
cis N. BALcH, Esq., PROFESSOR HERBERT OSBORN, PROFESSOR
EDWARD L. RIcE, DR. A. A. GOULD, DR. WOODWARD and PROFESSOR
KEITH of England, and a Professor of Zoology, at Harvard, all vig-
orously protesting against the evil and the uselessness of multiplying
names. PROFESSOR RICE, president of the Ohio Academy of Science,
says: ‘“‘Within recent years the estimate of the number of known
species of animals has reached 522,400 and with this enormous com-
plex each tyro has been at liberty to trifle: it is like turning a child
loose in the card catalogue of the library across the street. No won-
der that a friend should exclaim in cynical disgust that he has given
up the scientific nomenclature in favor of popular names on'the ground
that the latter are more definite and less confused.’’ This complaint,
as every zoologist knows, is not a new one. WoopwWarb, in his in-
comparable ‘‘Manual of Mollusca,’’ published “seventy years ago, ina
footnote on synonyms, says: ‘‘In PFEIFFER’S Monograph of Helicide,
a family containing seventeen genera, no less than three hundred
and thirty generic synonyms are noted; to this list Dr. ALBERS, of
Berlin, has lately added another hundred of his own invention!” I
regret to say that I added ten more in my ‘‘Pulmonifera of Maine’, in
1864, though half of these were promptly relegated to the synonomy
column, the other half were finally recognized, namely: Pallifera,
Strobila, Helicodiscus, Striatura and Punctum. These genera were
based on structural peculiarities, the lingual membrane, the mandible
and shell even to its microscopic markings. BINNEY threw doubt on my

23

observations on Punctum until DR. SCHACKO, of Berlin, in a study of
the allied European species, pygmeza, established the correctness of my
work.

The multiplication of generic terms has not been confined to
students of mollusca; ornithologists, entomologists, botanists and
doubtless students of other divisions are uttering their anathemas
against this ruthless destruction of the Linnean idea. So far and so
rapidly has it gone in botany that a distinguished botanist at Harvard
averred sarcastically that you had to consult the morning paper for
the latest name! The distinguished zoologist, DR. CHARLES SEDGWICK
MINOT, in a paper on “Zoological Problems”’ in speaking of the
Linnzan system of nomenclature, says: “‘We have retained the form,
while we have rejected the principle of nomenclature introduced by
LINNAEUS, who used a generic name in a wide sense to indicate the
kind. . . . . . At present genera are also special groups and
approximate to a single species so far has the subdivision gone. It
results that the name we call generic is no longer generic in value. Of
the two extremes the Linnzan is, I believe, preferable. I expect to
see a large number of genera set aside hereafter.’’ The evil of the
whole matter is that while we respect the work of our leaders in mala-
cology a rigid attitude insists that priority must be recognized despite
the man who gives the name. ‘An original’? as AUDUBON calls him
= RAFINESQUE; a curious character who conceived a ridiculous
method of classification = BOLTEN, or one who never saw or figured
the soft parts stands in the same catagory with the masters. MR.
JUKES BROWNE, in the Journal of the Malacological Society of London,
(Vol. XI, p. 59,) in his synopsis of the family Veneridx, in discussing
nomenclature says, “‘Again if BOLTEN’s Museum Catalogue is rec-
ognized as a scientific publication, and is not excluded from the law
of priority, his names would supplant those of LAMARCK, which have
been in general use for a century and’ more. Moreover BOLTEN’S
Catalogue gives no definitions of genera or sub-genera and is absolutely
devoid of any scientific value; while LAMARCK’S genera were properly
discriminated and defined. I hold, therefore, that such a displace-

24

ment of names is unjust, unnecessary and inconvenient, and as the
Zoological Congress has now resolved that exceptions may be made
in the rule of priority I hope that BOLTEN’s Catalogue may soon be
declared an exception. Meantime I refuse to be bound by the trammels
of this rule in the light fashion which some still advocate, I shall,
therefore, retain the name Callista. . . . I shall not accept the
revived use of the names Cytherea and Paphia, as proposed by Dr.
DALL, who adopts and adapts them from BOLTEN.”’

DR. SAMUEL H. SCUDDER in his great work on the Butterflies of
Eastern United States and Canada, says: “Call things by what names
one will, I only ask that the facts of nature be rightly interpreted;
and where differences are found, that they be given their proper values
as nearly as we can determine them, absolutely regardless of the
effect it is to have upon the paltry question of names. Names can
never have absolute fixity until we have absolute knowledge of all
the facts regarding the features they represent, and the sooner this
truth is recognized the better for all concerned.”

In the light of this dictum, is the flood of new generic names
based upon a study of the soft parts, the embryology, the early stages
of the shell, etc.? With the exception of ORTMANN on the Unionide
and BAKER on the Limniadz I do not recall any systematist who has
proposed a new genus based on the soft parts. PROFESSOR PAUL
BARTSCH, in acknowledging my paper, writes as follows: ‘‘ Your
paper which you so kindly sent me, ‘Observations on Living Lamelli-
branchs of New England,’ has come to hand, and I have enjoyed very
much looking it over. I am particularly pleased with your intro-
duction.

“T think we are all ready to cry out when it comes to nomenclature
and yet I do not see that there is any chance whatsoever of checking
the tendency to split up until this will have been done to the limit.
I believe when we will know all there is to be known about ‘critters’
we will begin to regroup and bring likes and likes together and will
then probably be able to understand a little more fully where the
knots in the meshes of our web should be placed. When I look at

20

IREDALE and his efforts in Rissoide, etc., I feel like shrieking; and
yet I can see some excuse for what he is driving at. Only I wonder
if it would not be possible to say in words what he is trying to express
in generic terms and achieve the same ends. However, the trend
seems to be toward the multiplication of terms. I remember well
seeing a manuscript a little while ago in which someone was mono-
graphing the pelicans of the world. I think there are twenty-two
recognized forms which he split up into twelve genera. At the time
I thought what a blessing that we still have popular names by which
we may recognize our birds. After all, in the ornithological field,
the popular names have been the most stable of all. I might say the
same is true of botany, because when I take up a modern systematic
treatise, after having allowed my botanical studies to lie dormant for
fifteen years or more, I find it necessary to look for popular terms to
re-identify my subjects. So you see it is the trend all around.

““May the Lord have mercy on the man who lays aside a subject
for as long a period as you have, and then takes it up again with fresh
enthusiasm and vigor, because he will find himself a stranger in-a
strange land; that is, in such a tangle of changed nomenclature that
it will seem as though he has never really known his subject. One
thing, however remains, and that is, truth will always come to the
surface and basic facts such as you are giving us regardless of the
nomenclatorial vicissitudes to which the species may be subjected
will always stand to receive full merit. Therefore, let me congratulate
you and let me wish you ever so many years of activity as fruitful and
forceful as your present effort.”

PROFESSOR BARTSCH fully realized my dilemma as to names. It
was hopeless for me to do more than to refer to the second edition
of GOULD’s “Invertebrata’”’ so that the student could instantly refer
to a reliable figure of the species indicated. These figures to the
number of 357 I drew on wood and they have been widely copied
though rarely acknowledged. PROFESSORS VERRILL and SMITH in
their “Invertebrate Animals of Vineyard Sound and Adjacent Waters”’
used many of them giving me full credit for the same. It is true I

26

might have copied C. W. JOHNSON’S names from his valuable catalogue
published by the Boston Society of Natural History, six years ago,
but these will soon be antiquated. That one may fully realize the
ridiculous absurdity of the situation let me take for example Fusus
islandicus. This animal is a good illustration of the unstable character
of nomenclature. It is not a Fusus but has been known as one for over
acentury. Had I published these notes in 1859 a reference to the latest
and highest authority at that time would have compelled me to use
the generic name Tritonium; if published in 1870 it would have
appeared as Sypho, while its diminutive companion, looked upon by
some as a variety only of zslandicus, would have been regarded as
belonging to a different sub-family with the generic name Chrysodomus;
had I waited until 1874, when I might have published most of my
notes, it would have been regarded as Neptunea. In 1889 it would
have been called Chrysodomus, and now the latest systematic catalogue,
(JOHNSON) published only six years ago, recognizes it a Colus, and
even its specific name changed too. Now the authorities for the
above mentioned changes are among the leading ones on the subject
in America: STIMPSON, DALL, VERRILL and JOHNSON. Is it fair to
call me antiquated when I wish simply to indicate the shell of which
the soft parts are drawn? A distinguished authority of Jurassic
ammonites, QUENSTEDT, I believe, actually suggested using numbers to
indicate the successive species found in the various deposits of the
Jura. If we were to use numbers for species and islandicus were 224,
for example, that number would hold no matter whether it were
Buccinoid, Fusoid, or some other family. So in using the name Fusus
islandicus it is a name found associated with all the above names as a
synonym, and the leading name used by ForBES and HANLEYy,
JEFFREYS, GOULD and other authorities.

The taxonomist should become familiar with Louis AGAssiz’s
“Essay on Classification,” first published as an introductory chapter
in his great work ‘Contribution to the Natural History of the United
States,’ afterwards published separately by LONGMAN. It was most
unfortunate that his definition of the catagories of classification could

2d

not have been established, but, nevertheless, there were many features
that could have been adopted. He often reminded us in his lectures
that species of a genus varied but little in size, that is you could not
have under the same generic term one species the size of a mouse and
another the size of a bear. With families no great departure in size
would be shown, yet W. G. BINNEY, in commenting on my discovery
that Helix minutissima, the smallest land shell in the world, had a
mandible composed of sixteen separate plates and understanding that
the jaw of Orthaliscus undatus was composed of separate plates would
include both species in the same family! —one a turreted shell from
45 to 50 mm. in height, the other a discoidal Helix less than one half
a mm. in height; or including under the same generic name Helix
alternata, 20 mm. in diameter and Helix asteriscus, 2 mm. in diameter.

The rational binomial terms of LINNEAUS that have endured
for over a century have now been encumbered by inserting the names
of varieties into the major names of the species, such as Pyramidula
cronkhitei catskillensis or Modiolus (Brachydontes) demissus plicatulus!

The bitterness which many students feel against the work of
systematists in flooding nomenclature with a mass of generic names is
little understood by those who defend the practice. PROFESSOR J. S.
KINGSLEY, of the University of Illinois, writes me; ‘“‘I have read with
the greatest interest your remarks upon the vagaries of nomenclature
and say Amen to all of them. This constant changing of names is
anathema to me, and I refuse to allow the ‘latest’ name in many cases
to appear in the Journal of Morphology. I loathe Amblystoma, I
spurn Amiatus and I adhere to Acanthias, Natica is good enough for
me, I still talk occasionally of Ameba, of Limulus and of Crangdon.
But you and I are old fashioned and we do not appreciate the great
advance in science which results in re-naming something already
well named!”

PROFESSOR HAROLD S. COLTON, of the University of Pennsylvania,
in a letter to me says: ‘“‘My sympathies are with you on the matter
of the names of animals. I wonder if I ever sent you my tirade against
systematists of a few years ago in “‘Science.’”” The names of animals now

28

mean nothing. I have to teach my students the ‘binomial’ system
of nomenclature and after they have worked with animalsa short time,
I am forced to admit that the system is not binomial and the so-called
scientific name is not as permanent as the common name. The whole
situation is so outrageous, that I feel like annihilating certain offend-
ing systematists.”’

The Royal Academy of Belgium has just issued a volume of over
800 pages entitled Les variations et leur hérédité chez les mollusques, by
Dr. PAUL PELSENEER. The author is one of the world’s leading
authorities on mollusca. He is the author of mollusca in LANKASTER’S
“Treatise on Zoology.”” In glancing through PELSENEER’S ponderous
work one finds the general use of old generic names. Helix is the
leading term with twenty-two modern generic names in brackets and
many others whose modern generic names are suppressed. Lamelli-
branchs is good enough for him, the awkward name Pelecypoda does
not appear. A glance at the exhaustive indices indicates the con-
servative attitude of this distinguished malacologist.

29

BUATE 1

Figure 1. Entalis striolata.

2. Acmea testudinalis.

(A), showing head, branchia, branchial arteries, mantle,
papille.

(B), tentacle greatly enlarged.

(C), mouth showing radula within.

3. Acmea alveus.
(A), head thrown to one side.

(B), enlarged view of head with tentacles and mouth
from below.

PLATE I.

MM Nyy, é

a |

=
BS

= \

Figure 4.
5);

6.

10.

a

PLATE: II

Crepidula fornicata.
Crepidula plana.
Crepidula convexa.

Crucibulum striatum.
(A), young shell.
(B), showing egg clusters.

(C), in act of crawling.

Cemoria noachina.

(A), ventral view.

Margarita undulata.

(A), greatly enlarged view of marginal tentacles.

Margarita helicina.

(A), enlarged view of snout, with enlarged papille at end
of snout.

Trochus occidentalis.

PLATE ff.

PLATE Ii

Figure 12. Skenea planorbis.
13. Rissoa minuta.
14. Lacuna vincta.
15. Lacuna neritoidea.
16. Scalaria groenlandica.
17. Turritella erosa.

18. Aporrhats occidentalis.
(A), immature specimen from below.
(B), enlarged view of foot showing caudal appendage.
(C), enlarged view of eye.

(D), bifurcated end of proboscis.
19. Turbonilla nivea.

20. Menestho albula.

PEATE SEIT.

ai.

e22:

Zo

24.

25:

26.

ile

28.

29.

PLATE IV
Velutina levigata.
(A), genital organ.
Velutina zonata.
Lamellaria perspicua.

Natica heros.

(A), foot cleft with proboscis extended.

Natica triseriata.

(A), tentacles turned back on shell, greatly enlarged.
Natica clausa.
Natica immaculata.
Natica duplicata.

Bela decussata.

PLATE EY.

Figure 30.

ole

oz:

oo:

4.
35.

36.

PEATE. V

Columbella lunata.

Columbella avara.
(A) and (B), head, (C), operculum.

Nassa obsoleta.

(A), proboscis extended and feeding on shell.

Nassa trivittata.

(A), tentacles expanded in a straight line.
Buccinum undatum.
Buccinum cinereum.

Fusus islandicus.

PLATE V

Figure 37.
38.
39.

40.

PLATE VI

Fusus pygmeus.
Fusus decemcostatus.
Trophon clathratus.

Busycon canaliculatum.

PLATE VI

Figure 40.

Al.

43.

PLATESVIL

(A) Busycon canaliculatum, egg chain issuing from shell.

(B) Busycon canaliculatum, egg chain showing proximal
end.

Ranella caudata.

(A), showing great elongation of foot.

Trichotropis borealis.

(A), another attitude of head.

Admete viridula.

(A), enlarged view of tentacle.
Alexia myosolis.
Carychium exiguum.

Melampus bidentatus.

PLATE: Vit

Prat Vill

Figure 4. (A), Crepidula fornicata.
dD. (A), Crepidula plana.
6. (A), Crepidula convexa.
8. Cemoria noachina.
10. (B), Margarita helicina.
14. (A), Lacuna vincta.

16. (A), Scalaria groenlandica.

Figure 21.

24.

46.

47.

48.

49.

PLATE IX

Velutina lxvigata.

(B), Natica heros.

(C), outline of adult shell reduced to size of early stage
showing difference of form.

(C), Busycon canaliculatum.
(A), Trichotropis borealis.

Melampus bidentatus.

(A), top view of nucleus.

Diaphana debilis.

(A), shows the reversed nucleus.
Philine sp?

Vermetus lumbricalis.

PEATE IX

Me Ate, tos
ede
f

Ao

Se Ne

She

SMITHSONIAN

iin

9088 00095 6524

|