TRUNCATELLID^. 



97 



a short thread, which is attached to the object of support ; and 

 by this it haugs suspended at pleasure. 



Spurious Species of Cyclophorid^e. 



Cyclostoma cincinnatlensis. Lea, not Anthony & DeKay; is an Amiiicola, 



and C. lupidaria, Say, Linsley, and Kiktland, is a species of Pomati- 



opsis, q. V. 

 Cyclostoma marginalis, Kirtland (Ohio Rep.), 



and C. tnarginata, Say, are species of Pupa, Fig. 195. 



q. V. 

 Cyclostoma tricarinata, Say, is a Valvaia. 

 Ctenopoma rugulosum, Pfeiffer, may, perhaps, 



prove an inhabitant of Florida. A single 



specimen found there is here figured. Ctenopoma rugtdosum. 



Family THUNCATELLID.E. 



Lingual membrane with seven rows of recurved, hooked 

 teeth. Animal with a broad, produced, bilobed muzzle, ten- 

 tacles flattened, sub-triangular, eyes sessile on the middle of 

 their upper bases. Foot very short and rounded. Opercu- 

 lum horny, subspiral. Shell lengthened, truncated, with a 

 rounded aperture. 



TRIJ^CATELLA, Risso. 

 Animal with a small foot, against the end of which teste the 

 operculum when the animal is withdrawn ; the tentacles are short, 

 acute; the snout is extended beyond 

 them as much as the whole length of Fig. 196. 



the animah The shell is carried hori- 

 zontally. Operculum horny, hardly 

 spiral, with a basal nucleus. Shell 

 imperforate, but with an umbilical Amm^\ or Truncateiia. 

 groove, cylindrical, turreted, usually 

 pellucid and smooth, of a reddish horn-color ; the upper whirls 



