MANUAL OF NATURAL HISTORY. 133 



sessile at base of tentacles ; gills placed ob- 

 liquely across neck ; foot expanded, simple ; 

 operculum none ; shell conical, non-spiral ; 

 aperture wide, with an internal testaceous 

 appendage. 



36. FAMILY. Bonnet-Shells (Capulidse). Eyes on 



outer bases of tentacles ; gills placed obliquely 

 across neck ; foot folded on itself; operculum 

 none ; shell simple, cap-shaped ; aperture wide, 

 simple internally. Marine. 



37. FAMILY. White-Ears (Vanicoridae). Eyes ses- 



sile on outer bases of tentacles ; foot small ; 

 circular, winged at the sides, and with a 

 narrow lobe in front ; operculum ovate, 

 horny ; shell spiral, white ; last whorl large ; 

 aperture semi-lunar. Marine. (Naricacea, 

 Phil.) 



38. FAMILY. Worm -Shells (Vermetidse). Eyes 



sessile on outer bases of short tentacles ; foot 

 cylindrical, produced and truncate in front, 

 not fit for walking ; operculum circular, spi- 

 ral ; shell attached, tubular, irregularly spiral. 

 Marine. 



39. FAMILY. False Tooth-Shells (Cteecidse). Eyes 



sessile on the head behind bases of ten- 

 tacles ; foot short ; operculum circular ; shell 

 many-whorled, sub-cylindrical, arched ; apex 

 sub-spiral, deciduous. Marine. 



40. FAMILY. Apple -Snails (Ampullariidse). Ten- 



tacles subulate ; eyes on peduncles at their 

 outer bases ; mantle with a siphon ; rostrum 



