GASTEROPODA. 



55 



The only known species, Swainson includes with the 

 Mitra, and Reeve with Conus. 



Terebellum. Lam. — (Seraphis Gray.) Shell ob- 

 long, smooth and convolute ; spire pointed and 

 short ; aperture narrow and long ; right lip rather 

 sharp and truncated, left lip quite smooth. Ani- 

 mal, having the head prolonged into a proboscis ; 

 the eyes on very long stalks, tentacula entirely 

 absent ; the foot appears to have an operculum. — 

 1 species, also fossil. 



T, subulatum, the only species, is brought from 

 the Indian seas ; it is thin, delicate, and prettily 

 marked with bands and cloudy spots : the fossil subulatum. 

 species are curious, having the spire concealed by the last 

 whorl. 



Rostrotrema. Lycett. — Shell differing from Rostel- 

 laria, by having the upper canal not carried over the spire ; 

 and the outer lip but little dilated, extending above, only 

 as far as the last whorl but one. This canal has not a 

 thickened edge. It differs from Strombus, in having no 

 winged sinus. — About 1 1 species, fossil. 



Pterodonta. U Orb. — Shell oval, somewhat long 

 and swollen, lengthening regularly with simple smooth 

 whorls, the last having an entire dilated lip, which some- 

 times is thickened outwardly, but has neither notch nor 

 sinus ; sometimes prolonged at the base ; the aperture 

 slightly narrowed, oval, and with a short, oblique canal in 

 the upper part ; inside the outer lip a tooth, or rather a 

 prolonged fold. — 6 species, fossil. 



Spinigera. U Orb. — Shell like Rostellaria, but the 

 whorls are keeled, and the outer lip has a spine on the 

 keel, which being formed at every half whorl, gives it 



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