MOLLUSCA, 181 



1. Shell convoluted. The shell has an oval or linear 

 mouth parallel with its length. The whorls, which are small 

 segments of large circles, are wrapped round the pillar, and 

 the one rising a little above the other, embrace or inclose 

 the preceding ones. The four following families appear to 

 belong to this division. 



Family 1. Conusidce. -Furnished with a long proboscis, 

 and produced tentacula, with the eyes near the summit on 

 the outside. The lid is placed obliquely on the foot, and 

 is too small to fill the mouth of the shell. The genera Co- 

 nus and Terebellum form this family. 



Family 2. Cypreadce. Cloak enlarged, and capable of 

 folding over the shell. There is 110 lid. The genus Cy- 

 prea is the type. 



Family 3. Oimladce. Both extremities of the aperture 

 canaliculated. The inhabitants of all the genera, Ovula, 

 Calpurna, and Volva, are unknown. The last genus in- 

 cludes the Sulla patula of Pennant. 



Family 4. Volutadce Canal of the aperture abbreviated. 

 Pillar-lip plaited. The foot appears to be destitute of a lid. 

 The genera are numerous ; Voluta, Oliva, Cymbium, Mar- 

 ginella, Cancellaria, Mitra, Ancilla, Volvaria, and Torna- 

 tella. The last genus contains the Voluta tornatilis of Bri- 

 tish writers. 



2. Shell turreted. The whorls of the shell, the revolving 

 spire of which is subconical, scarcely embrace one another, 

 but are merely united at the margins. Three families may 

 here be established. 



Family 1. Buccinidce. Canal short, scarcely produced 

 beyond the anterior margin of the lip, and bent towards the 

 right. The tentacula are remote, and the head is destitute 

 of a hood. The mouth has a retractile proboscis. The fol- 



