Page

FIG. 7. The suture of a portion of the lateral grove
uniting with the above, in which the trans-
verse pieces are concave.

8. Suture of the intermediate grove divided at
the ridge (Fig. 3. b.). Teeth obtusan-
gular.

9. A circular space round the mouth, co-
vered with little oblong scales. In the
centre is the mouth with its five converg-
ing teeth.

10. Outside of one of the five pyramidal jaws,
in which the teeth are planted.

a. The jaw. b. The tooth.

11. Inside of ditto: a. the jaw, consisting in

ternally of two triangular transversely
furrowed, and probably molary plates.
12. A little bristle, terminating in a knob with
three awns, planted amongst the spines
on the shell, and, according to Cuvier,'
a species of Polype (Pedicellaria).
13. Another Pedicellaria? expanded like a
tripetalous blossom.

14. One of the spines of Echinus esculentus.

PLATE III. B. CRINOIDEANS.

FIG. 1. Pentacrinus Asteria

208-211

2. Portion of ditto, exhibiting the suckers on the

PLATE V. BIVALVE MOLLUSCANS.

Page 240

FIG. 1. Solen Siliqua..

a. The foot. b. The shell.

N.B. The two figures in outline shew variations in shape assumed by the foot, under different circumstances.

FIG. 1. Voluta æthiopica, to shew the animal. a. The eye, shewing iris and pupil.

b. The right hand tentacle.

c. The proboscis exserted.

d. The frontal margin of the head.

e. The respiratory tube or siphuncle.

f. Appendage at its base. Analogous to the
crus infundibuli in Nautilus?1 Owen.

g. g. The two gills, of which the right hand one
has but one series of laminæ.

h. Termination of the alimentary canal.

1 Owen's Mem. on Naut. Pompil. t. v. h.

264

267

301

282

i. i. The right hand margin of the mantle.
k. The male organ.

1. l. The foot.

FIG. 2. Ianthina

...

a. The mouth, composed of two vertical cartila-
ginous lips, minutely toothed at the margin.
b. The shell.

c. The air-vesicles forming an out-rigger.

PLATE VII. CEPHALOPODS.

FIG. 1. Loligo cardioptera.

2. Spirulea prototypus

a. The shell.

3. Ocypus unguiculatus.'

a. The suckers.

b. The arms.

PLATE VIII. ANNELIDANS.

Page

291

316

308