GASTROPODA 553 



2. OxYGYRTJS 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 TcBnioglossa except that the radula and jaws are absent : 



2 families, both marine. 



Key to the families of Gymnoglossa: 



flj Apical whorls normal ; animals often parasitic 1. Eultmidae 



tta Apical whorls sinistral 2. Pyramidellidae 



Family 1. EULIMIDAE. 



Shell usually elongate, conical, and multispiral, white in 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. EuLiMA 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 hriareus. 



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: 



a. Columella without a fold 1. Turbonilla 



tfa Columella with an oblique fold' 2. Odortomia 



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

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

 cosmopolitan. 



