CONCHOLOGY. 113 



ventricose. Inhabits the Indian seas. Four living species. 

 Seven fossil, 



Delphiimla laciniata. Delphinula distorta. 



D. turbinopsis. D. rugosa. 



FAMILY XVI. 

 TuKiuxACEA. Eight genera. 



1. Genus SolaHiim. PI. XI. 

 Animal. Unknow^n. 



Shell. Orbicular, depressed, umbiUcus large and conical, crenu- 

 lated or dentated on the inner margin of the whorls ; aperture 

 not modified by the last whorl of the spire, which is entirely flat ; 

 no columella. Inhabits the Indian seas. Seven living species. 

 Eight fossil. 



Solarium granulatum. Solarium Isevigatum. 



S. perspectivum. S, stramineura. 



S, hybridum. S. variegatum. 



S. luteum. 



2. Genus Trochus. PI. XI. 



Animal. Spiral, having the sides of the body often ornamented 

 with digitated or lobed appendages, and provided with a short 

 foot rounded at its two extremities ; head provided with two 

 tentacula more or less elongated, having the eyes upon a dilation 

 of their external base ; mouth without superior tooth, but fur- 

 nished with a spiral lingual band. 



Shell. Marine, found in almost all parts of the world, some 

 smooth, others knotted, spined, tuberculated, or undulated ; thick, 

 generally pearl), spire sometimes depressed, at others elevated and 

 pointed at the summit, sharp or carinated at its circumference, fre- 

 quently umbilicated, not always; aperture transversely depressed, 

 the margins not united at the upper part ; columella arched and 

 twisted, often projecting forward; operculum horny, thin, with, 

 numerous spiral whorls, increasing from the centre to the circum« 

 11* 



