OF MOLLUSCA. 27 



tacles conical, close together over the mouth, with the eyes near 

 their base. Foot very large, expanded, nicked on each side in front, 

 elongate behind, often becoming truncated. 



1. H. ventricosa, t. 22. f. 1, 2; t. 95. f. 3. 



2. H. minor, t. 23. f. 1, 2; Adams, Gen. Moll. t. 15. f. 1. 



The hinder part of the foot separates spontaneously when the 

 animal is irritated. 



b. Trapezodonta. Abnormal lateral teeth trapezoid, curved. Shell 

 internal (see p. 10). 



Fam. VIII. LAMELLABIADjE. 



Mantle covering the thin ear-shaped shell, produced, and with 

 a deep notch in front in the place of the respiratory siphon. Head 

 moderate. Proboscis elongate, strong, retractile. Mouth vertical, 

 covered internally with a strongly armed horny epithelian or pre- 

 hensile collar. Tongue linear, spirally twisted behind (as in Pur- 

 pura Lapillus) . Gills single, crescent-shaped, hence appearing double. 

 Teeth 1 • 1 • 1 or 2 • 1 ■ 2 ; central simple, triangular, with diverging 

 branches at the base ; lateral trapezoid, simple, curved, toothed 

 (fig. 13). Operculum none. 



1. Coriocella. 



Body oblong ; mantle vesicular, areolated, with two narrow lobes 

 in front. Foot small, narrow. Teeth 1 ■ 1 ■ 1 ; lateral large, versa- 

 tile. Shell large, spiral, internally ear-shaped. 



1. Coriocella nigra, t. 104. f . 3 ; t. 104. f . 4 ; t. 167. f. . 



The Coriocella nigra grows to a large size. The shell is green 

 when fresh, but soon fades and becomes white. The foot is not one- 

 fourth of the size of the mantle. The trunk long, like that of Buc- 

 cinum. The tentacles depressed, close together, united on the inner 

 side over the top of the cavity of the proboscis, with the eyes near the 

 tips. The canal of the mantle is very distinct and lined with a car- 

 tilaginous skin. Operculum none. 



2. Lamellaria. 

 Body depressed, smooth, notched in front. Foot very large, broad, 

 produced behind. Teeth 1 • 1 ■ 1, U.-Lamellaria. 



lateral, large, versatile (ng. 13). — 

 Love'n, t. 4.f. 15. Shell large, spiral, 

 internally ear-shaped. 



1. L. tentaculata, t. 103. f. 11; 



t. 103. f. 4; Forbes $■ Hanley, 

 Brit. Moll. t. P.P. f. 2. 



2. L. ? neritoidea, t. 103. f. 2. 



3. L.? Audouini, t. 105. f. 3, 4. 



4. L. latens. Cryptocellal., Adams, Gen. Moll. t. 21. f. 4 



