FAMILY STROMBID&. 



Shell ini perforate, usually solid, with ttirriculated spire, and 

 more or less dilated or winged lip ; the lip frequently digitated, 

 with usually a sinus near the base for the protrusion of the head 

 of the animal ; aperture mostly canaliculated at each extremity, 

 the columella callous, without plaits. Operculum corneous, 

 small, generally unguiculate, sometimes oval, with apical nucleus. 



Animal with sessile or pedunculated eyes, slender tentacles, 

 contractile annulated proboscis, short siphon, varying foot. 

 Dentition taenioglossate. 



Corresponds with the family Alata of Lamarck. 



Subfamilies. 



Subfamily STROMBIN^E. Animal furnished with large eyes, 

 placed on thick cylindrical peduncles; the iris highly colored, 

 often in concentric zones, tentacles slender, rising from the 

 middle of the eye-peduncles ; foot narrow, adapted for leaping 

 rather than walking ; siphon very short, not extending beyond 

 the anterior canal of the shell ; mantle with an extension laying 

 in the posterior canal ; penis long, narrow, with a hook-like or 

 bifurcated extremit} 7 . Dentition. Central tooth multicuspid, 

 short ; laterals, one on each side, subtrigonal, with crenulated 

 margins; marginals falciform, narrow, sharp-pointed, with finely 

 denticulated margin (PL 1, fig. 1). 



Shell with expanded, entire, or shortly digitated lip, with an 

 anterior marginal sinus, and usually a posterior prolongation; 

 aperture canaliculated anteriorly and posteriorly. Operculum 

 narrow, unguiculate. 



Subfamily APORRHAIN^E. Eyes small, sessile at the outer 

 bases of the narrow, subnlated tentacles; foot rather small, 

 oblong, adapted for walking. Operculum suboval. Dentition : 

 central tooth subquadrangular. the edge multicuspid ; laterals 

 transverse, with entire margins ; marginals elongated, narrow, 

 curved, sharp, with entire, margins (PI. 11, fig. 25). 



Shell with turriculated spire, the lip much dilated, usually 

 digitated, with an incomplete canal or notch in front. 



(99) 



