authors, are described as small, and the _A. villosa_ was suspected by
Brugière to be young. The _A. hirsuta_ is said by Conrad to have the
valves minutely striated, granulated, and covered by a strong hirsute
epidermis; the scuta, compared with the other valves, are very large;
the entire length of this specimen was a quarter of an inch. The _A.
villosa_ is described as having smooth valves, and apparently the
peduncle alone is hirsute. Now, in young individuals of _Lepas
australis_, the peduncle is hairy, whilst in full-grown specimens it is
quite smooth. Again, in some varieties of _L. fascicularis_, the thorax,
prosoma, and cirri are hirsute, whereas they are generally quite smooth;
hence I am inclined to suspect that _A. villosa_ is the young, in a
state of variation, of _L. anatifera_; and that _A. hirsuta_ bears a
similar relation to _L. anserifera_. In Lamarck’s ‘Animaux sans
Vertèbres,’ _Pollicipes villosus_ of Sowerby is quite incorrectly given
as a synonym to the above _A. villosa_.
[69] The _Anatifa hirsuta_ of Quoy and Gaimard is the _Ibla
quadrivalvis_ of this work.
ANATIFA ELONGATA. _Quoy_ et _Gaimard_. Voyage de l’Astrolabe, Pl.
xciii, fig. 6.
This, I think, is certainly a distinct and new species, but I am unable
to decide whether to place it in Lepas or Pæcilasma. It is briefly
described and pretty well figured in the above work. It was procured at
New Zealand, but it is not stated to what object it was attached. The
capitulum is much elongated, and one inch in length; the peduncle is
from six to eight lines long. The carina is said to be very narrow; it
is not stated whether it terminates downwards in a fork or disc; judging
from the figure, it extends some way up between the terga, the basal
ends of which are bluntly pointed. The scuta are almost quadrilateral.
The peduncle is short, yellow, and tuberculated. The general appearance
of the drawing makes me suspect that it is a Pæcilasma.
CLYPTRA. _Leach._ Zoological Journal, vol. ii, p. 208, July,
1825.
Leach has most briefly characterised a specimen in Savigny’s Museum,
from the Red Sea, under the above name of _Clyptra_. It has only four
valves, and its peduncle is smooth; by the latter character it is
distinguished from Ibla. Apparently this is a distinct and new genus.
* * * * *
Mr. J. E. Gray, in ‘Proc. Zoolog. Soc.,’ 1848, p. 44, quotes a
description by Stroem (‘Nym. Saml. Danske,’ 1788, 295, n. iii, f. 20),
namely, “_Lepas testâ compressâ 7-valvis, stipite lamellosâ_.” It is
found attached to _Gorgonia placomus_, in the North Sea. I suspect that
this is the common _Scalpellum vulgare_, and that Stroem counted the
valves only on one side, overlooking the rudimentary and concealed
rostrum; and this would give seven for the number of the valves. Had it
not been for the expression “stipite lamellosâ,” I should have thought
this might have been an unknown species of Dichelaspis.
SCALPELLUM LÆVIS. _Risso._ Hist. Nat. des Product. de l’Europe
Mérid., 1826, Tom. iv, p. 385.
The chief characteristic of this species appears to be indicated by its
specific name. It is found in the Mediterranean, attached to Cidarites.
I am inclined to believe that it is distinct from _S. vulgare_.
SCALPELLUM PAPILLOSUM. _King._ Zoolog. Journal, vol. v, p. 334.
Captain King has described this species, taken from the depth of 48
fathoms, on the coast of Patagonia, in Lat. 44° 30´ S. It is probably
distinct, but is so imperfectly described, that not even the number of
the valves is given.
POLYLEPAS (POLLICIPES), Sinensis. _Chenu._ Illust. Conchyliolog.,
Pl. II, fig. 7.
This species is said to come from China; it is nearest to _P. spinosus_,
but is, I think, distinct.
EXPLANATION OF THE PLATES.
TAB. I.
Fig.
1. _Lepas anatifera_, (nat. size.) _Var._, with a row of square,
dark-coloured marks on the scuta and terga.
1_a._ _Lepas anatifera_, external view of carina, magnified
thrice.
1_b._ _Lepas anatifera_, lateral view of carina, magnified thrice;
var. _dentata_.
1_c._ _Lepas anatifera_, internal view of right-hand scutum, to
show the tooth at the umbo.
2. _Lepas Hillii_, (nat. size.)
3. _Lepas pectinata_, (magnified thrice.)
3_a._ _Lepas pectinata_, var. (_spirulæ_), tergum, magnified
thrice.
4. _Lepas anserifera_, (nat. size.)
5. _Lepas australis_, (nat. size.)
5_a._ _Lepas australis_, carina, external view of, magnified
twice.
6. _Lepas fascicularis_, (nat. size,) with its peduncle, together
with those of three other specimens, imbedded in a vesicular
ball of their own formation, of which a slice has been cut
off to show the internal structure. The specimen is in the
College of Surgeons.
6_a._ _Lepas fascicularis_, carina of, nat. size.
6_b._ _Lepas fascicularis_, var. _villosa_.
6_c._ _Lepas fascicularis_, var. _villosa_, carina of.
6_d._ Part of the membrane from one side of the peduncle of _Lepas
fascicularis_, with the ball removed, showing one of the
cement-ducts, and the orifices through which the vesicular
membrane forming the ball has been secreted; greatly
magnified; viewed from the outside.
TAB. II.
Fig.
1. _Poecilisma Kæmpferi_, (magnified two and a half times.)
1_a._ _Poecilisma Kæmpferi_, carina of.
2. _Poecilisma aurantia_, (magnified two and a half times.)
3. _Poecilisma crassa_, (magnified twice.)
3_a._ _Poecilisma crassa_, carina of.
4. _Poecilasma fissa_, (magnified five times.)
5. _Poecilasma eburnea_, (magnified five times.)
5_a._ _Poecilasma eburnea_, carina of, external view of.
5_c._ _Poecilasma eburnea_, carina of, lateral view of.
5_b._ _Poecilasma eburnea_, scutum, internal view of.
6. _Dichelaspis Warwickii_, (magnified five times.)
6_a._ _Dichelaspis Warwickii_, transverse section of the top of
the peduncle, showing the deeply-notched end of the inwardly
bent carina; magnified five times.
6_b._ _Dichelaspis Warwickii_, _var._, scutum and tergum.
7. _Dichelaspis pellucida_, (magnified five times.)
7_a._ _Dichelaspis pellucida_, basal end of carina of, much
magnified.
8. _Dichelaspis Lowei_, (magnified nearly ten times.)
8_a._ _Dichelaspis Lowei_, fork of carina of, viewed internally.
9. _Dichelaspis Grayii_, (magnified eight or nine times.)
10. _Dichelaspis orthogonia_, (magnified six times.)
10_a._ _Dichelaspis orthogonia_, carina, lateral view of.
10_b._ _Dichelaspis orthogonia_, basal end of carina, viewed
internally, much magnified.
TAB. III.
Fig.
1. _Oxynaspis celata_, (magnified three times.)
1_a´._ _Oxynaspis celata_, with the skin of the encrusting horny
zoophyte removed. (_a_), scutum; (_b_), tergum; and (_c_),
carina.
2. _Conchoderma virgata_ (magnified twice.)
2_a._ _Conchoderma virgata_ carina, viewed externally.
2_b._ _Conchoderma virgata_ summit of capitulum, showing the terga
from vertically above.
2_c._ _Conchoderma virgata_ var. _chelonophila_, (magnified four
times).
2_d._ _Conchoderma virgata_ var. _Olfersii_, (scutum.)
3. _Conchoderma Hunteri_, (magnified five times.)
4. _Conchoderma aurita_, (nat. size,) with the rudimentary carina
exhibited on the right hand.
4_a._ _Conchoderma aurita_, summit of capitulum, viewed from
vertically above, showing the ear-like appendages and the
rudimentary terga.
4_b._ _Conchoderma aurita_, section near the bases of the ear-like
appendages, showing their folds.
4_c._ _Conchoderma aurita_, (var.), scutum.
5. _Alepas minuta_, (magnified five times.)
6. _Alepas cornuta_, (magnified five times.)
TAB. IV.
Fig.
1. _Anelasma squalicola_, (copied from Lovèn.) The ovigerous
lamellæ are seen within the edges of the aperture of the
capitulum. Enlarged about one and a half times.
2. _Anelasma squalicola_, (from Lovèn), with the membranes removed
from one side of the capitulum and of the peduncle,
exhibiting the body.
(_a._) External membrane of the capitulum.
(_a, a._) Inner membrane of ditto, lining the sack, and
separated from the external membrane by a double fold of
corium.
(_b._) The ovigerous lamellæ, the edge projecting beyond the
orifice of the capitulum.
(_c._) Penis, succeeded by six pairs of rudimentary cirri.
(_d._) Probosciformed mouth.
(_e._) Orifice of the acoustic (?) sack.
(_f._) Ovigerous frænum.
(_g._) Ovarian branching tubes filling up the peduncle.
(_h._) Outer integument of peduncle, lined by corium and
muscles, continuous with the outer membrane (_a_) of the
capitulum.
3. _Anelasma squalicola_, Small portion of the outer integument
of the peduncle, greatly magnified, exhibiting the natural
lines of splitting, and showing that it is composed of
several distinct portions or layers, which are displayed by
the corners having been turned over. Three of the branching
filaments, filled with pulpy corium, are given; the others
have been cut off. The membrane (_a_) extends under (_b_),
but not under the circular patches of membrane, (_c, c_.)
4. _Anelasma squalicola._ Mandibles, seen from the side towards
the maxillæ.
5. _Anelasma squalicola._ Mandibles, seen from the side towards
the labrum.
6. _Anelasma squalicola._ The right-hand, rudimentary cirrus, the
third from the mouth.
7. _Anelasma squalicola._ Maxillæ. The thin horny apodeme, (_a_).
8. _Ibla Cumingii_, female, (magnified four times.)
8_a´._ _Ibla Cumingii_, female, (magnified about five times), with
the right hand valves and right side of the peduncle
removed. The Male (_h_) is seen attached in the sack. The
peculiar form of the body, caused by the small development
of the prosoma, by the distance of the first and second
pairs of cirri, and by the distance of the mouth from the
adductor muscle, (a dark dotted circle opposite _i_,) and
lastly, the remarkable course of the oesophagus over the
adductor muscle, together with the outline of the stomach,
are here all exhibited.
(_a._) Scutum; the end of the large rounded adductor
muscle, which was attached to the valve now removed,
near its apex, is plainly seen.
(_b._) Tergum.
(_c._) On a line with this letter, is seen the largely
bullate labrum, forming a blunt overhanging projection.
(_d._) Palpus, close to the upper segment of the pedicel of
first cirrus.
(_e._) Orifice of the acoustic (?) sack, between the bases
of the first and second cirrus.
(_f._) Caudal appendages.
(_g._) Branching ovarian tubes within the peduncle.
(_h._) Male, on the same scale, lying in its natural
position within the sack, with the lower part of its
peduncle bent upwards, and imbedded in the corium and
muscles of the female.
(_i._) Adductor scutorum muscle.
8_b´._ _Ibla Cumingii_, Internal view of the scutum and tergum,
and of the upper part of the outer integument of the
peduncle, with its horny spines magnified about three
times.
8_c´._ _Ibla Cumingii_, A small portion of the outer integument of
the peduncle, greatly magnified, showing the horny
persistent spines; two of the spines have been torn out.
9. _Ibla quadrivalvis_; internal view of scutum and tergum, and of
the upper part of the outer integument of the peduncle;
magnified four times.
9_a´._ _Ibla quadrivalvis_, Penis supported on a long
unarticulated projection; greatly magnified.
TAB. V.
Fig.
1. Male of _Ibla Cumingii_, magnified thirty-two times.
(_a._) Mouth.
(_b._) A slight double fold, formed by the basal edge of the
labrum, and by a lower fold, which at (_h_) becomes well
developed; the latter is a rudimentary representation of
the double membrane and valves forming the capitulum.
(_c._) Eye.
(_d, d._) Torn membrane from the sack of the female,
constricted round the body of the male.
(_e._) Terminal or basal point, with the prehensile larval
antennæ, represented on rather too large a scale.
(_f._) The imbedded portion of the male.
(_g._) Two pairs of cirri.
(_h._) The fold above alluded to, concealing a small portion
of the slightly retracted thorax.
2. The male of _Ibla Cumingii_, viewed from vertically above;
magnified about sixty times. The dotted lower portion,
represents the outline of the thorax and the positions of
the cirri, which, from standing below the mouth, could not
be well seen, when the summit of the mouth was in the
proper focus.
(_a._) Labrum, largely bullate.
(_b._) Palpi.
(_c._) Mandibles.
(_d._) Maxillæ.
(_e._) Outer maxillæ; between which and the crest of the
labrum, the orifice of the oesophagus can be obscurely
seen.
(_f._) Anus.
(_g._) Rudimentary caudal appendages, under which is the
pore leading from the vesiculæ seminales.
(_h._) Posterior cirrus. (_i._) Anterior cirrus.
3. Male of _Ibla Cumingii_; labrum and palpi, as seen with the
eye on a level with the summit of the mouth.
4. Male of _Ibla Cumingii_, Posterior cirrus (_h_ in fig. 2) much
magnified.
5. Male of _Ibla Cumingii_, Larval antennæ; from the terminal
point of the body (_e_ in fig. 1), as seen with a 1/8th of
an inch object glass.
6. Male of _Ibla Cumingii_, Outer maxillæ.
7. Male of _Ibla Cumingii_, Mandibles, with the underlying
articulated membrane, forming the side of the mouth.
8. Male of _Ibla Cumingii_, Maxillæ, with the apodeme.
9. Complemental Male of _Scalpellum vulgare_, attached over the
fold in the occludent margin of the scutum of the
hermaphrodite.
(_a._) Orifice of the sack of the male.
(_b._) Spinose projections above the rudimental valves; at
the bottom of the figure are represented, as seen through
the whole thickness of the animal, the prehensile larval
antennæ.
(_d._) The depression for the attachment of the adductor
scutorum muscle of the hermaphrodite; see fig. 15 _a´_.
(_e_, _e._) A transparent layer of chitine, which forms a
border to the occludent margin of the scutum of the
hermaphrodite. This border supports long spines, which are
connected with the underlying corium by sinuous tubuli.
10. The basal (normally anterior) portion of the above
complemental Male, greatly magnified, viewed dorsally from
above, exhibiting the larval prehensile antennæ, attached
to the antero-sternal surface of the animal.
11. One of the antennæ of ditto, viewed laterally and on the
outside.
12. Ditto, ultimate segment of.
13. Body of the above complemental male, consisting of the thorax
supporting the four pairs of limbs, and of the terminal
abdominal lobe.
14. Small portion of the outer integument of the complemental
male, as seen with a 1/8th of an inch object glass.
15. _Scalpellum vulgare_ (hermaphrodite), magnified three times.
(_a, a._) Complemental males.
(_b._) Rostrum, of which a separate enlarged figure (_b´_)
is given.
15_a´._ Scutum of the hermaphrodite _Scalpellum vulgare_,
internal view of.
(_a._) Fold on the occludent margin.
(_d._) Pit for the adductor muscle.
TAB. VI.
Fig.
1. _Scalpellum ornatum_, (female, magnified seven times.)
1_a´._ _Scalpellum ornatum_, Upper latus, viewed internally.
1_b´._ _Scalpellum ornatum_, Scutum of full-grown specimen, viewed
internally, much magnified.
(_a._) Depression for the adductor muscle.
(_b._) Depression for the reception of the male.
1_c´._ _Scalpellum ornatum_, cutum of half-grown specimen, viewed
internally, much magnified, on same scale with fig. 1 _b´_.
The depression (_b_) for the reception of the male is here
seen, in almost the first stage of formation.
1_d´._ _Scalpellum ornatum._ An imaginary section through the
cavity (_x_) in which the male is lodged.
(_a._) Section of the shell of the scutum of the female.
(_b._) A layer of chitine homologous with the shell, and
_partially_ lining the scutum.
(_c._) The inner lining (of chitine) of the sack of the
female.
(_d._) A double fold of corium.
2. _Scalpellum rutilum_, (magnified two and a half times).
2_a´._ _Scalpellum rutilum_, Internal view of scutum, enlarged.
(_a._) Depression for the adductor muscle.
(_b._) Cavity for the reception of the male.
2_b´._ _Scalpellum rutilum_, External view of carina.
2_c´._ _Scalpellum rutilum_, Section across middle of carina.
3. Complemental Male of _Scalpellum Peronii_, greatly magnified.
4. Complemental Male of _Scalpellum villosum_, greatly magnified.
(_a´._) Natural size.
4, _a, b, c._ Ditto, valves separated.
(_a._) Scutum.
(_b._) Tergum.
(_c._) Carina.
5. Complemental Male of _Scalpellum rostratum_, a restored
figure, greatly magnified. Scutum and rudimentary carina
correct.
6. _Scalpellum Peronii_, one and a half the natural size.
(_a._) Rostrum a little more enlarged, front view of.
7. _Scalpellum rostratum_, magnified six times.
(_a._) Rostrum, front view of.
8. _Scalpellum villosum_, magnified one and a half the natural
size.
8_a_, _b._ _Scalpellum villosum_
(_a._) Internal view of rostrum.
(_b._) Internal view of sub-rostrum.
TAB. VII.
Fig.
1. _Pollicipes cornucopia_, (one and a half nat. size.)
1_a._ _Pollicipes cornucopia_, internal view of valves.
2. _Pollicipes polymerus_, (one and a half nat. size.)
2_a._ _Pollicipes polymerus_, internal view of valves.
3. _Pollicipes mitella_, nat. size.
3_a´._ _Pollicipes mitella_, nat. size, internal views of
(_a._) Scutum, and of
(_b._) Tergum, showing articular fold.
3_b´._ _Pollicipes mitella_, Internal view of other valves, in a
small specimen, showing the manner in which the valves of
the lower whorl overlap each other.
(_a._) Upper latera.
(_b._) Carina,
(_c._) Sub-carina, both viewed a little obliquely.
(_d._) Rostrum,
(_e._) Sub-rostrum, both viewed a little obliquely.
4. _Pollicipes spinosus_, one and a half nat. size.
5. _Pollicipes sertus_, one and a half nat. size.
TAB. VIII.
Fig.
1. A piece of rock bored in two directions by _Lithotrya
dorsalis_, with the calcareous basal discs in the upper
cavity, serving as a bridge for crossing an old cavity.
About twice natural size.
1_a´._ _Lithotrya dorsalis_, (nearly twice nat. size), with the
basal calcareous cup adherent; (_a_), rostrum on same scale,
seen externally.
1_b´._ _Lithotrya dorsalis_, rostrum and the rostral corners of
the two scuta, together with a small portion of the
subjacent membrane of the peduncle, with its calcareous
scales; viewed externally, greatly magnified, showing the
inferior crenated edges of the scales.
1_c´._ _Lithotrya dorsalis_, basal calcareous cup, one and a half
the natural size; this is the largest specimen which I have
seen.
2. _Lithotrya Nicobarica_, (magnified nearly twice;) attached to
the rock, copied from Reinhardt; (_a_), rostrum on the same
scale, with the other valves, seen externally; (_b_),
section of the row of discs; (_c_), extreme point of the
peduncle, extending beneath the row of discs.
2_a´._ Rock bored by _Lithotrya Nicobarica_, showing the row of
calcareous discs, copied from Reinhardt.
3. _Lithotrya cauta_, magnified between seven and eight times;
(_a_), scutum; (_b_), tergum.
3_c._ _Lithotrya cauta_, latus, greatly magnified.
3_d._ _Lithotrya cauta_, uppermost scales of the peduncle, greatly
magnified.
3_e._ _Lithotrya cauta_, star-shaped discs of hard chitine,
supported on a peduncle of the same substance, taken from
the lower exterior surface of the peduncle, very greatly
magnified.
4. _Lithotrya Rhodiopus_, (magnified five times,) internal views
of; (_a_), scutum; (_b_), tergum; (_c_), latus; (_d_),
carina.
5. _Lithotrya Valentiana_, (magnified between three and four
times;) (_a_), internal view of scutum and tergum, locked
together; (_b_), capitulum seen from vertically above;
(_c_), internal view of carina; (_d_), section across the
middle of the carina.
TAB. IX.
Fig.
1. _Lithotrya truncata_, (magnified four times.)
1_a´._ _Lithotrya truncata_, capitulum seen from vertically above,
not so distinctly represented as in fig. 5 _b_, Pl. VIII.
1_b´._ _Lithotrya truncata_, internal views of valves; (_a_),
rostrum, with a few subjacent scales of the peduncle; (_b_),
scutum; (_c_), tergum; (_d_), carina.
2. A portion (about 1/10th of an inch square) of the surface of
attachment of the peduncle of _Pollicipes polymerus_, seen
from the outside, greatly magnified, showing the small
circular (_bb_) patches of cement, poured out from the
cement-ducts (_aa_) which lie within the peduncle.
2_a´._ A portion of a section, still more magnified, through the
basal membrane of the peduncle, through one of the loops of
the cement-ducts (_aa_), and through one of the circular
patches (_b_) of cement.
3. Cement gland, duct, and ovarian tubes of _Conchoderma aurita_;
(_aa_), ovarian tubes, with ova in process of formation;
(_b_), cement-gland; (_c_), cement-duct.
4. _Conchoderma virgata_, enlarged, with one side of the capitulum
and of the peduncle removed, to show the form and position
of the body.
(_a._) tergum, edge of.
(_b._) mouth, with one of the palpi seen on the inner, upper
corner.
(_c._) adductor scutorum muscle.
(_d._) orifice of acoustic (?) sack.
(_e._) scutum, occludent margin of.
(_f._) branching ovarian tubes within the peduncle.
(_g._) filamentary appendage on the prosoma.
(_h._) ditto, close to basal articulation of the first
cirrus.
(_i._) ditto, on the pedicel of the first cirrus.
(_j._) ditto, on the pedicel of the third cirrus.
(_k._) ditto, on the pedicel of the fourth cirrus.
(_l._) ditto, on the pedicel of the fifth cirrus.
(_m._) edge of the carina.
(_n._) prosoma.
5. Apex of one of the filamentary appendages of _Conchoderma
aurita_, greatly magnified, exhibiting the included
branching testes.
6. Acoustic (?) sack of _Conchoderma virgata_, taken out of the
acoustic meatus, with the diaphragm from the summit removed;
greatly magnified.
7. Terminal part (magnified seven times), of the peduncle of an
elongated specimen of _Scalpellum vulgare_, slit open, with
the corium removed, showing the two cement-ducts (_aa_), and
a row of circular patches (_bb_) of cement, by which the
peduncle, along its rostral edge, is attached to the thin
horny branches of the coralline. The larval antennæ are seen
at the terminal point, and the two cement-ducts can be
traced into them.
TAB. X.
_Figures all greatly magnified._
Fig.
1. Mandibles of _Pollicipes mitella_: exhibiting the upper (_a_)
and lower (_b_) articulations, and the three principal
muscles; the short upper cut off muscle runs to its
attachment at the base of the palpus.
2. Mandibles of _Lithotrya dorsalis_, exhibiting four (_aa_)
roughened, thin, ligamentous apodemes for the attachment of
the muscles.
3. Mandibles of _Scalpellum Peronii_.
4. Mandibles of _Ibla Cumingii_.
5. Mandibles of _Lepas anatifera_.
6. Palpus of _Lepas anatifera_.
7. Palpus of _Pollicipes mitella_.
8. Palpus of _Alepas cornuta_.
9. Maxilla of _Lepas anatifera_.
10. Maxilla of _Lithotrya dorsalis_, exhibiting the horny, rigid
apodeme (_a_) buried in muscles, together with the two other
principal bundles of muscles.
11. Maxilla of _Ibla Cumingii_.
12. Maxilla of _Lithotrya Rhodiopus_.
13. Maxilla of _Pollicipes polymerus_.
14. Maxilla of _Pollicipes mitella_.
15. Maxilla of _Poecilasma eburnea_.
16. Outer maxilla of _Conchoderma virgata_; (_a_), orifice of the
olfactory cavity, the inner delicate chitine membrane of
which is seen within, the specimen having been treated with
caustic potash.
17. Outer maxilla of _Pollicipes mitella,_ showing the two
principal muscles, and the prominent, tubular, (_b_)
olfactory orifices.
18. Caudal appendages, and basal segments of the sixth pair of
cirri, of _Lepas anatifera_; (_a_), anus; (_b_), caudal
appendages; (_c_), lower segment of pedicel of sixth cirrus;
(_d_), upper segment of ditto; (_e_), basal segments of the
two rami.
19. Caudal appendage (right-hand side) of _Pollicipes sertus_.
20. Caudal appendage (right-hand side) of _Scalpellum Peronii_.
21. Caudal appendage (right-hand side) of _Scalpellum vulgare_.
22. Caudal appendage (right-hand side) of _Pollicipes cornucopia_.
23. Caudal appendage (left-hand) _Lithotrya dorsalis_; (_a_),
caudal appendage; (_c_), lower segment of pedicel of sixth
cirrus; (_d_), upper segment of ditto; (_e_), segments of
one of the rami.
24. Portion of caudal appendage of _Lithotrya dorsalis_, highly
magnified.
25. _Pollicipes polymerus_; anterior ramus of the second cirrus.
26. _Lepas anatifera_; a segment of the sixth cirrus, showing the
arrangement of the spines; (_a_), main anterior spines, of
which there is a corresponding row on the opposite side;
(_c_), dorsal tuft.
27. _Pollicipes polymerus_; a segment of the sixth cirrus, showing
the arrangement of the spines; (_a_), main anterior spines,
of which there is a corresponding row on the opposite side;
(_b b_), calcareous shields on the dorsal surfaces, with
tufts of fine spines near their upper edges.
28. _Alepas cornuta_; sixth cirrus of; (_a_) basal portion of one
ramus, consisting of numerous segments; (_k_), the other and
almost rudimentary ramus.
29. _Poecilasma fissa_; segments of the sixth cirrus, showing the
arrangement of the spines; (_a_), anterior spines; (_c_),
dorsal tufts.
INDEX.