MOLLUSCA. 
387 
Genus 33. — B E L E MNIT E S.— Lamarck. 
Generic Character. —Shell straight, conical, elongated, capable 
of being separated into two parts, the outer one a solid sheath, 
produced above and excavated with a conical cell beneath; the 
inner nucleus conical, and multilocular, divided by numerous 
transverse septa, perforated by a central tube. 
Belemnites subconicus .— The Sitbconic Belemnites. 
Plate LXXXIII. fig. 29. 
Lower part somewhat cylindrical; the upper part conical and 
attenuated. Fossil, found in Britain in chalk marl. 
ORDER III_TRACHELIPODA. 
Posterior part of the body spirally convolute, separated from 
the feet, and constantly enveloped in a shell ; foot free, de¬ 
pressed, attached to the lower base of the neck, on the anterior 
part of the body, and forming a member of locomotion; shell 
spiral, and enveloping. 
Section I.—Zoophagous Trachelipoda. 
The animals are entirely marine, having a protruding syphon, 
and respiring water only, which reaches the branchiae by this 
syphon ; they are devoid of maxillae ; provided with a retractile 
proboscis, and feed on other animals. 
TRIBE I.-INVOLUTE. 
Shell destitute of a canal, but having its aperture notched 
or effuse at the base, and its volutions compressed, and convo¬ 
luted in such a manner as the external one nearly envelopes the 
others. 
Genus 1.—CONUS.— Linnceus. 
Generic Character. —Shell turbinate, aperture longitudinal, 
linear, entire, narrow, and effuse at the base; pillar smooth, 
destitute of teeth ; shape of a reversed cone. 
2 i 2 
