GASTROPODA 553 



2. OXYGYRTTS Benson. Shell" milky white, rounded on the periph- 

 ery and keeled only near the aperture, which has no notch : 4 species, 1 

 on the South Atlantic coast. 



0. keraudreni D'Orbigny. New Jersey to Texas; West Indies. 



DIVISION 3. GYMNOGLOSSA. 



Similar to the Tcenioglossa except that the radula and jaws are 'absent : 

 2 families, both marine. 



Key to the families of Gymnoglossa: 



a x Apical whorls normal ; animals often parasitic 1. EULIMIDAE 



c a Apical whorls sinistral , 2. PYBAMIDELLIDAE 



FAMILY 1. EULIMIDAE. 



Shell usually elongate, conical, and multispiral, white hi color and 

 polished; foot long and narrow; proboscis very long, sometimes longer 

 than the body; animal often parasitic, sucking the juices of its host by 

 means of the long proboscis: 5 genera and numerous species. 



1. ETJLIMA Risso. Shell slender, tall, sometimes bent; operculum 

 horny, spiral: 50 species, mostly southern, many parasitic. 



E. oleacea Kurtz and Stimpson (Fig. 867). Shell small, solid, 

 with 12 flattened whorls; color pale brown; aperture small, oval; length 

 6 mm.; width 1.5 mm.: Vineyard Sound to North Carolina; parasitic 

 on Thy one briareus. 



2. STYLIFER Broderip. Shell thin, transparent, ovate or elongate, 

 with a very sharp apex which is sometimes bent; operculum wanting; 

 aperture small ; tentacles slender ; eyes sessile : 20 species ; cosmopolitan ; 

 parasitic on or in the integument of echinoderms, often producing tumors. 



S. stimpsoni Verrill. Shell white, swollen, with 4 to 5 whorls, the 

 lowest very large, with an impressed revolving line just below the 

 suture; length 3.75 mm.: Massachusetts to New Jersey; on Strongylo- 

 centrotus. 



FAMILY 2. PYEAMIDELLIDAE. 



Shell conical, elongate or ovate, usually small, with apical whorls 

 sinistral and excentric; operculum horny, spiral; tentacles ear-shaped, 

 joined at the base; eyes sessile: several hundred species. 



Key to the genera of Pyramidellidae here described: 



O! Columella without a fold 1. TURBONILLA 



a a Columella with an oblique fold 2. ODOSTOMIA 



1. TURBONILLA Risso. Shell long and slender and multispiral, 

 white or yellow, ribbed or striate; lip incomplete: 50 species; 

 cosmopolitan. 



