326 Mr. W. Clark on the Animal of Dentalium Tarentinum. 
branchiz to its terminus, and submitted its substance to micro- 
scopic powers without discovering a trace of an intestine, which 
is usually the easiest organ to be detected by its colour and dis- 
tension. I have carefully watched thirty dividuals at a time, 
and never saw any rejectamenta from the posterior process ; but 
in the same period frequent discharges anteriorly from the centre 
of the mantle, of foraminiferous spoil enveloped in mucus. I 
finally observe, that on the animal being removed from the shell, 
the medial branchial canal is distended, but in a short time col- 
lapses from the evaporation of the fluid, and exhibits a deep ca- 
naliferous groove; and when the canal is not quite full, one or 
two globules, precisely like those of a spirit-level, may be made 
with the shghtest pressure to float backwards and forwards from 
the posterior sphincteroid process to the branchie. Many other 
circumstances can be added in proof of the posterior entry of the 
branchial water, but I have already transgressed the limits of 
conciseness, and it is time to take some notice of the nervous sy- 
stem, salivary glands, the stomach and its contents, and the sub- 
stances which fill up the body from the branchiz to the posterior 
terminus. 
At the base of the cesophagus is a cerebral mass of four mi- 
nute, pale pink, subcircular, finely-punctured ganglions, in form 
somewhat like the letter X, united by a nervous thread or collar, 
which encircles the cesophagus at the pot where it passes at the 
base of the foot into the stomach, and the fine filaments therefrom 
are distinctly visible passing to the stomach, and throwing off 
anastomosing lateral threads anteriorly to the foot, buccal orifice, 
and the other front parts of the body. 
The salivary glands are very large, coverig the base of the 
foot and the cesophageal ganglions, and envelope the buccal 
pouches so completely that they seem imbedded in them; they 
spring from each side the base of the mouth, and are two thick 
fasciculi, which consist of a multitude of very fine, long, light 
yellow capillary strands ; their extraordinary volume is necessary 
to produce a copious supply of fluid to lubricate the enormous 
quantity of Foraminifera these animals swallow, especially of the 
scabrous ones, as Bulimina pulchella, and the sharp-pointed La- 
gena amphora. 
The cesophagus, after emerging from the nervous collar, m- 
stantly enters the stomachal cavity, which is composed of a mus- 
cular membrane of a broad oval form, the anterior and larger 
portion thereof bemg occupied by an extremely strong gizzard, 
formed of a pair of subelliptical folding jaws with eighteen lamine 
bent towards the points on each side, and studded with very 
strong blunt teeth : this denticular frame is supported by fleshy 
lobes encased in corneous plates, and appears to be an organ 
nearly similar to the buccal mass of the ordinary Gasteropoda ; 
