MOLLUSCA. 
377 
elongated, gelatinous, pellucid, with a tail at its posterior extre¬ 
mity. 
Shell univalve, conical, compressed, unilocular, extremely 
thin, hyaline; apex convoluted into a spire ; back, in some spe¬ 
cies. forming a notched keel; aperture oblong and entire. 
Carinariafragilis. —The Fragile Carinaria. 
Plate LXXXIII. fig. 1. 
Shell excessively thin, hyaline, striated longitudinally, desti¬ 
tute of a dorsal keel. Inhabits the African seas. 
ORDER II— CEPHALOPODA. 
Head emanating from a bag-shaped mantle, and surmounted 
by inarticulated arms ; provided with suckers, and investing the 
mouth; two sessile eyes ; mouth provided with two horny man¬ 
dibles ; three hearts; the sexes in separate individuals. 
Sub-Division I.— Cephalopoda Sepiaria. 
Destitute of either external or internal shell ; but provided 
with a solid, free, calcareous, or cornuous substance, in the in¬ 
terior of the body. 
Genus 1. — SEPIA.— Linnceus. 
Generic Character. —Mouth terminal, invested by' ten arms 
provided with cups, of which two are placed on peduncles, and 
longer than the rest; body fleshy, depressed, free, and enveloped 
in a bag, which is obtuse behind, margined its whole length on 
either side by a narrow fin ; having a free, porous, opaque bone 
included within the body, close to the back. 
Genus 2. —LOLIGO.— Lamarck. 
Generic Character. —Mouth terminal, surrounded by ten arms, 
provided with cups, of which two are longer than the others, 
and placed on penduncles; body fleshy, enveloped in an oblong 
cylindrical bag, acuminated at the base, and provided with wings 
below; an elongated, thin, transparent, corneous lamina, en¬ 
closed within the body, near the back. 
2 h 3 
