section parallel to the zones of growth,) they are triangular, elongated
transversely, with the carinal angle a rectangle. In width they equal
the seven subjacent scales of the peduncle, and are more than half as
long as the basal margin of the carina.
_Peduncle_, with the upper scales varying from circular to
quadrilateral, thrice as large as those in the second whorl; beneath
which, in the next three or four whorls, the scales rapidly decrease in
size; and beneath these the whole peduncle is studded with equal-sized,
rounded, calcareous beads, so minute as to be quite invisible to the
naked eye. This specimen was nearly ready to moult, and perhaps in
consequence of this, even the upper scales were most obscurely serrated
on their lower margins, and all the others quite smooth: there were some
much worn horny spines close to the bottom of the peduncle. Basal
calcareous cup slightly concave, of moderate size; its diameter, in the
one specimen examined, was 9/10ths of an inch; it was composed of
several layers. In the specimen figured (2 _a´_) by Reinhardt, instead
of a cup, there is a straight row of small discs, which are attached to
the walls of the cavity, as explained in the generic description.
_Mouth._--Palpi with their ends square and truncated; thickly clothed
with long spines.
_Mandibles_, with fully twice as many pectinations, (viz. from 16 to
20,) between the first and second main teeth, as between (viz. 8 to 10)
the second and third main teeth. Inferior angle, coarsely pectinated.
The distance between the tips of the first and second teeth, is
considerably less than between the tip of the second tooth and the
inferior angle.
_Maxillæ_, with the edge very slightly irregular; beneath the two great
upper spines there is a slight notch, with some small spines: inferior
angle slightly prominent, with a brush of moderately fine spines;
besides these, there are about seventeen pairs of large spines; sides
very hairy.
_Outer Maxillæ_, with the inner margin slightly concave, and with the
spines continuous.
_Cirri._--The segments in the three posterior pairs support three or
four pairs of long spines, with a single row of moderately long
intermediate spines; the dorsal tufts consist of a few rather thick, and
some long and thin spines. The front of the segments is not protuberant;
the whole surface is hirsute with minute comb-like scales. _Second
cirrus_, with the anterior ramus having its eight basal segments highly
protuberant and thickly clothed with spines, the upper nine having the
usual structure; the posterior ramus has four or five basal segments
thickly clothed with spines, and the twelve upper ones with the usual
structure. _Third cirrus_, with the anterior ramus having six segments
highly protuberant and thickly clothed with bristles, and the fifteen
upper ones on the usual structure; in the posterior ramus, only three or
four of the basal segments are paved with bristles. The spines on the
first three pairs of cirri, are coarsely and doubly serrated.
The _Caudal Appendages_ are more than twice as long as the pedicels of
the sixth cirrus, and equal half the length of the whole cirrus. In a
specimen in which the sixth cirrus contained twenty-two segments, the
caudal appendages actually contained twenty. The segments are thin, with
their upper edges clothed with serrated spines. The slip of membrane on
each side, whence this organ springs is united, for a little space, to
the lower segment of the pedicel of the sixth cirrus.
_Size and Colour._--Width of the capitulum rather above 4/10ths of an
inch; length, including the peduncle, (contracted by spirits,) nearly
one inch. Valves, as usual, dirty white, partly invested by yellow
membrane, furnished with a few minute yellow horny spines. Pedicels of
the first four cirri, caudal appendages, penis, the two posterior
thoracic segments, the segments of the cirri, and the trophi, clouded,
banded, or spotted, with blackish purple.
_Affinities._--This species, in the characters derived from the valves,
comes perhaps nearest to _L. Rhodiopus_; in the characters derived from
the animal’s body, it is nearest to _L. dorsalis_.
4. LITHOTRYA RHODIOPUS. Pl. VIII, fig. 4.
BRISNÆUS RHODIOPUS. _J. E. Gray._ Annals of Philosoph., vol. x,
(new series,) 1825.
---- ---- _J. E. Gray._ Spicilegia Zoolog., Tab. xvi, fig. 17,
1830.
_L. scutis terga ample obtegentibus: carinæ cristâ internâ tenui, in
parte superiore positâ: lateribus, superficie internâ symmetricè et latè
ovatâ, carinæ latitudinis plus quam tertiam partem æquantibus: tergorum
basali apice tenui, et angulo carinali producto: rostro et pedunculo
ignotis._
Scuta largely overlapping the terga. Carina with a slight central
internal ridge in the upper part. Latera with their internal surfaces
symmetrically and broadly oval, more than one third of the width of the
carina. Terga with the basal points narrow, and the carinal angle
produced. Rostrum and peduncle unknown.
Mandibles, with four times as many pectinations between the first and
second main teeth, as between the second and third; distance greater
between the tips of the first and second teeth, than between the tip of
the second tooth and the inferior angle. Maxillæ widely notched, with
the inferior part forming two obscure prominences.
Hab. unknown. Imbedded in a massive coral. Brit. Mus.
The specimens are in a rather bad condition, and have been
disarticulated. They are of rather small size; the rostrum and peduncle
are lost, and animal’s body much injured.
Valves white, thin, translucent; teeth on the projecting rims small,
narrow, standing further apart than their own width. The upper layers
have undergone but little disintegration or scaling off, and
consequently the carina and terga project freely. The valves, where not
rubbed, are covered by bright yellow membrane, which is thickly clothed
with rows of spines; these are small on the exterior surfaces, but are
very large and hooked in certain parts, as near the tergal margins of
the scuta, and on the carinal margins of the terga, and especially on
the inner face of the upper free part of the carina. Here the hooked
spines (fig. 4 _d_) are trifid or quadrifid, and are very conspicuous.
_Scuta_, as seen externally, triangular; they overlap half the width of
the terga; on their internal faces (fig. 4 _a_), in the upper projecting
part, there is a strong ridge, against which the scutal margin of the
terga abuts. There is a deep and conspicuous pit for the adductor
muscle.
_Terga_, as seen externally, nearly triangular. The ridge which leads
from the apex to the basal angle, is rounded, central, and extremely
prominent; but does not form a furrow, or include the overlapping margin
of the scuta. The basal angle is narrow, spur-like, and slightly
hollowed out on both margins. The growing corium-covered surface (fig.
4 _b_) is transversely elongated, with the occludent margin rounded, and
the carinal angle much produced, but not forming a roughened knob.
_Carina_ (fig. 4 _d_), concave within, with a slight central ridge in
the upper free portion. The inner growing surface is concave, almost
pentagonal, with a just perceptibly raised central rim in the upper
part, and with two minute prominences on each side, against which the
produced carinal angles of the terga abut.
_Rostrum_, lost.
_Latera_ (fig. 4 _c_), growing surface (or a section parallel to the
growth-layers,) symmetrically oval, more than one third as wide as the
basal margin of the carina. Several zones of growth preserved.
_Peduncle_, lost, but a few scales accidentally adhering to one of the
valves, show that they are crenated in the three or four upper whorls.
No basal calcareous cup was preserved, but by clearing out the base of
one of the holes in the coral, in which a specimen had been imbedded, I
found a little flat disc about the size of a pin’s head; it was composed
of two or three layers, and was externally coated by yellow membrane,
including the usual spindle-shaped bodies and tubuli. The cement-ducts
were also discovered after dissolution in acid. So that there could be
no doubt regarding the nature of the little disc.
_Mouth._--Labrum with a row of little blunt teeth.
_Palpi_, blunt, rather expanded at their ends, with the extreme margin
much arched and furnished with two rows of long spines; there is a
fringe of short spines on the straight inner side.
_Mandibles._--There are nine pectinations between the first and second
main teeth, and only two between the second and third teeth; the
inferior angle is coarsely pectinated, with one central spine twice as
long as the others. The distance between the tips of the first and
second main teeth, is greater than between the tip of the second tooth
and the inferior angle.
_Maxillæ_ (Pl. X, fig. 12).--These may be described as having their edge
formed into three prominences; or, as having a very wide notch under the
two upper great spines, and with the whole inferior part forming two
prominences. There are, altogether, about twelve pairs of spines, of
which two stand singly on the inferior side of the wide notch under the
two upper great spines. The spines on the inferior angle are rather
smaller than those above; sides hirsute.
_Outer Maxillæ_, with the inner margin slightly concave, and sparingly
covered with bristles.
_Cirri_, imperfectly preserved; the three posterior pairs have segments
of the usual character, bearing five pairs of very long spines, with the
usual little intermediate, the minute lateral, and the dorsal spines.
First cirrus lost; second and third with only their few basal segments
preserved, sufficient, however, to show that at least two or three
segments, in both the anterior and posterior rami of both cirri, were
paved with bristles.
_Pedicels_, as in the other species.
_Caudal Appendages_, lost.
This species comes very close, as far as the characters derived from the
trophi serve, to the _L. truncata_, though readily distinguished from
that species by the shape of the valves. On the other hand, the
capitulum of this species is distinguished with difficulty from that of
_L. Nicobarica_ and _L. cauta_; no doubt this difficulty is much
enhanced by the rostrum and peduncle having been lost.
5. LITHOTRYA TRUNCATA. Pl. IX, fig. 1.
ANATIFA TRUNCATA. _Quoy_ et _Gaimard_. Voyage de l’Astrolabe, Pl.
xciii, figs. 12 to 15, 1834.
_L. scutis in profundam tergorum plicam insertis: carinæ cristâ centrali
prominente et rotundatâ in parte superiore: rostro et lateribus
rudimentalibus, carinæ latitudinis quindecimam fere partem æquantibus._
Scuta locked into a deep fold in the terga: carina with a prominent
central rounded ridge in the upper part: rostrum and latera rudimentary,
about 1/15th of the width of the carina.
Mandibles, with nearly three times as many pectinations between the
first and second teeth, as between the second and third teeth; distance
between the tips of the first and second teeth equal to that between the
tip of the second tooth and inferior angle. Maxillæ widely notched, with
the inferior part forming two prominences. Caudal appendages shorter
than, or barely exceeding in length, the pedicels of the sixth cirrus.
Friendly Archipelago, Mus. Paris; Philippine Archipelago, Mus.
Cuming; imbedded in coral rock.
Capitulum rather thick, with the five main valves having their free
apices, diverging and truncated. The upper and old layers of shell do
not here scale off so readily as in many of the foregoing species; and
hence an unusually large proportional length of each valve projects
freely above the sack; and the valves are of unusual thickness. The
capitulum is very nearly as wide at its summit as at its base, owing to
the divergence of the apices of the valves. The scuta and terga are
articulated together by a conspicuous fold, which, when seen from
vertically above, (Pl. IX, fig. 1 _a´_,) appears like a deep
wedge-formed notch in the terga. On the exterior surfaces of the valves,
the teeth on the successive rims are approximate; on the inner surfaces,
the rims are covered by strong yellow membrane, which is generally
fringed with small horny spines.
_Scuta_, exterior surface convex, sub-triangular, with the apex
truncated: seen vertically from above, there is a small rectangular
indentation or fold which receives the projecting scutal margin of the
terga. The inner growing or corium-covered surface (fig. 1 _b_, _b´_) is
triangular, with its tergal margin _largely_ hollowed out. Along the
occludent margin there is a slight ridge, which terminates at the
rostral angle, in both the right and left-hand valves, in a rounded,
knob-like, roughened tooth. The lower part of the tergal margin is
slightly inflected and roughened, where it meets the corresponding lower
part of the scutal margin of the terga. There is a deep pit for the
adductor muscle. The interior surface of the valve above this pit is
faintly-coloured purple. The inner surfaces of both scuta and terga, are
roughened with little points.
_Terga_, seen externally, are almost quadrilateral (owing to the apex
being truncated), with the free margin facing the scutum, arched. Seen
vertically from above, each shows a deep fold, which receives the lower
part of the tergal margin of the scutum. In the foregoing species, a
prominent ridge runs down the exterior surface of the terga from the
apex to the basal angle, against which ridge, the margin of the
overlapping scuta abuts: here this ridge, instead of projecting straight
out, is oblique or folded over, and thus forms a furrow, receiving the
margin of the scuta. The interior growing surface of the tergum (fig. 1
_b´_, _c_), presents so irregular a figure, that it can hardly be
described; in area it quite equals the scuta; it is slightly concave; at
the upper point of the carinal margin, there is a large, rounded,
protuberant, roughened knob, which corresponds with a small knob on each
side of the inner face of the carina; these knobs seem firmly united
together by membrane. The scutal margin of the terga, in the upper part,
forms a shoulder, largely projecting over the scuta; on its lower part,
there is a small roughened projection. The occludent margin is arched
and protuberant, with a slight fold above the knob on the carinal
margin, just mentioned: this fold is caused by the protuberance of the
central internal ridge of the carina, but is so small, that when the
capitulum is seen from vertically above, it can hardly be distinguished.
Finally, the basal half of the carinal margin, runs in the same line
with the basal margin of the scuta.
_Carina_, moderately large; seen externally, the surface presents an
elongated triangle, with the apex truncated; on the internal face (fig.
1 _b´_, _d_) of the free part, there is (instead of being concave as is
usual) a great central ridge, which projects between the diverging
apices of the terga, as may be seen from vertically above; hence the
thickness of the upper part of the carina, in a longitudinal plane,
almost equals its breadth. The edge of this ridge is rounded. The inner
or growing surface of the carina is tinted purple, and lies in a plane,
oblique to the longer axis of the valve; it is triangular, with the apex
cut off, and the basal margin rounded and protuberant; it is not
concave. There is a central raised line or slight ridge on this inner
surface, and on each side in the upper part there is a small, white,
roughened knob, corresponding with the similar knobs on the carinal
margins of the terga.
_Rostrum_ (fig. 1 _b´_, _a_), rudimentary; in one specimen it was about
1/50th of an inch in width; it is either as wide, or only half as wide,
as the subjacent scale on the peduncle.
_Latera_, rudimentary, placed between the edges of the carina and the
terga; rather smaller than the rostrum; almost cylindrical, slightly
flattened, enlarged at each zone of growth, with one or two sharp teeth
or spines on both faces; imperfectly calcified; in width barely 1/15th
part of the carina.
_Peduncle_, short; the scales alone in the uppermost whorl are plainly
toothed; they are transversely elongated, and almost quadrangular, and
are nearly twice as large as those in the second whorl. Beneath this
second whorl, there are two or three whorls, with scales, graduated in
size; and the rest of the peduncle is covered by rather distantly
scattered, minute, rounded or acutely pointed scales: the pointed scales
are directed upwards, and are best developed under the carina. The basal
calcareous cup, judging from two specimens, is thin, and not much
developed.
_Size and Colour._--The largest specimen was nearly 6/10ths of an inch
across its capitulum. The calcareous valves are dirty white. The sack
is (after having been long kept in spirits) pale coloured, excepting a
small purple space, between the scuta and another over the carina. The
three posterior segments of the thorax and portions under the second and
third cirri, the trophi, the pedicels and the anterior faces of the
segments (especially of the basal segments in the second and third
cirri), and a spot on their dorsal surfaces, and the penis are all
coloured dark purplish-black. The prosoma is pale coloured.
_Mouth._--Crest of labrum with a row of bead-like teeth and hairs.
_Palpi_ bluntly pointed, with neither margin hollowed out.
_Mandibles_, with eight pectinations between the first and second main
teeth, and three between the second and third teeth; inferior angle
coarsely pectinated, with a central spine much longer than the others;
the distance between the tips of the first and second main teeth, is
about equal to that between the tip of the second tooth and of the
inferior angle.
_Maxillæ._--Under the two upper long spines (associated with some
smaller ones), there is a slight and wide hollow; and the whole inferior
edge obscurely forms two blunt points, with the spines on the lower
projection smaller than the upper spines.
_Outer Maxillæ_, considerably concave in front, with the spines almost
discontinuous in the middle part.
_Cirri._--First pair rather far separated from the second pair. The
segments of the three posterior cirri bear three or four pairs of main
spines, and are otherwise characterised like the foregoing species.
_First cirrus_, with its anterior ramus much thicker than the posterior
ramus, and of nearly equal length; all the segments, except the two
terminal ones, thickly clothed with serrated spines. _Second cirrus_
considerably shorter than the third cirrus: anterior ramus with the
seven basal segments very protuberant, and paved with bristles, and the
four terminal ones on the usual structure; posterior ramus, with the
five basal segments paved (but much less thickly than in the anterior
ramus), and the nine terminal ones on the usual structure. _Third
cirrus_, the anterior ramus, with the five basal segments, thick and
paved, and eleven terminal segments on the usual structure: posterior
ramus, with one basal segment paved, and sixteen other segments on the
usual structure. In the posterior rami, however, of both the second and
third cirri, it is difficult to draw any distinct line between the paved
segments and the others.
_Caudal Appendages_, short, either just exceeding in length the pedicels
of the sixth cirrus, or equalling only the lower segment: segments
flattened, cylindrical, six in number, there being, in the same
individual, twenty-one segments in both rami of the sixth cirrus.
6. LITHOTRYA VALENTIANA. Pl. VIII, fig. 5.
CONCHOTRYA VALENTIANA. _J. E. Gray._ Annals of Philosoph., vol. x
(new series), 1825.
_L. scutis in profundam tergorum plicam invertis: tergorum opposito
superiore margine, plicâ alterâ æquè profundâ instructo: carinæ cristâ
prominente centrali, marginibus quadratis, in parte superiore: rostro
rudimentali: lateribus et pedunculo ignotis._
Scuta locked into a deep fold in the terga; the latter having a second
equally deep fold on the opposite upper margin. Carina with a prominent,
central, square-edged ridge in the upper part: rostrum rudimentary.
Latera and peduncle unknown.
Animal unknown.
Red Sea, imbedded in an oyster-shell. British Museum.
_General Remarks._--The two specimens in the British Museum are small,
and in an imperfect condition, without the peduncle or the latera, and
without the body of the animal. The capitulum so closely resembles that
of _L. truncata_, that it is quite superfluous to do more than point
out the few differences. It is just possible, though not probable, that
this form may prove to be merely a variety or younger state of _L.
truncata_, in which case this latter name would have to be sunk. The
difference, though one only of degree, in the form of the terga of the
two species is conspicuous, and there is a slight difference in the
carina, and again some dissimilarity in habits.
_Description._--The valves, as just stated, generally resemble those of
_L. truncata_; scarcely any appreciable difference can be detected in
the scuta; the apex, however, of the inner surface seems coloured a
darker purple. The terga, as seen from vertically above (Pl. VIII, fig.
5 _b_), have a fold or indentation on the upper or occludent margin, as
large and as conspicuous as that receiving the margin of the scuta: this
fold, as seen on the inner corium-covered surface (fig. 5 _a_), descends
below the roughened knob at the upper angle of the carinal margin, which
is not the case with the slight fold in the same place in _L. truncata_;
its presence seems caused by the edge of the central internal crest, in
the upper part of the carina, being square (instead of round, as in _L.
truncata_), and thus more deeply affecting the outline of the terga,
between which it is inserted. The upper part of the scutal margin of the
terga, as seen internally (fig. 5 _a_), overlaps the scuta in a large
_rectangular_ projection. From the depth of the two opposite folds,
namely, that caused by the tergal edge of the scuta and that by the
crest of the carina, the inner face of the tergum is divided into two
almost equal areas. The carina has its central crest square (fig. 5 _c_,
_d_,) instead of being rounded as in _L. truncata_. The inner growing or
corium-covered face is nearly at right angles to the longitudinal axis
of the whole valve, instead of being oblique to it; it is convex or
protuberant, with a central raised line, and two little knobs on each
side of the upper part; the two lateral margins are slightly hollowed
out, and the basal margin is not highly protuberant. The rostrum is
excessively minute, barely above 1/200th of an inch in width; it is a
little enlarged at each zone of growth. Latera lost; no doubt they were
rudimentary.
A fragment of a posterior cirrus, which adhered to one of the valves,
shows that each segment supported four pairs of spines.
Width of the capitulum before disarticulation, probably was about 1/10th
of an inch.
* * * * *
_Species mihi non satis notæ, aut dubiæ._
ANATIFA VILLOSA. _Brugière._ Encyclop. Meth. Des. Vers., tom. i,
1789, p. 62, Pl. clxvi.
On ships: Mediterranean.
ANATIFA HIRSUTA[69] _Conrad._ Journal of the Acad. of Nat. Sc.,
Philadelphia, vol. vii, 1837, p. 262.
On fuci, Fayal, Azores.