IlELIClNIDiB. 



ICT 



We are indebted for this little species to Dr. Jay, of New York, in Miiose 

 honor it is named. It cannot be confounded witli the European species 

 N. Jluviatilis—of which it is the American analogue— not only on account 

 of its constant coloration, but still more on account of its conical si)ire 

 and canaliculated suture. {Rrrluz.) 



Nerithiajajjana, Recluz, Jouru. de Conch. I, 1.57, pi. vii, f. 13 (1850). 



I am unable to add any information regaixling this species or 

 its habitat, further than what is contained in the above copy of 

 the original description and figure. , 



Spurious Species of Xeritella. 



Neritina striata, Besleri, from New Orleans is quoted in the synonymy 

 of Neritina zebra, Bkug., of Cayenne, by Recluz, in Journ. de Conch. 

 I, 152, and 



Neritina zif/za;/, Sowekby, from Florida, as a synonym of Neritina lineo- 

 lata, Lam., of Cayenne. I can find no description or further infor- 

 mation regarding the former, or any authority for the habitat given 

 of the latter. 



Family HELICINID^. 



Lingual membrane long, narrow, with numerous longitu- 

 dinal series of teeth, arranged 00, 5, 1, 5, 00 ; see description 

 of Helicina orhiculata, on p. 108. Head proboscidiforni ; 

 tentacles subulate, with the ejes at their outer bases. Foot 

 elongated. Operculum non-spiral, annular, semi-oval or sub- 

 triangular, with concentric elements, thick and testaceous, or 

 thin and horny. Shell with the aperture semilunar. 



Fig. 214. 



Head of Helicina 

 orbiculata. 



Fig. 215. 



HELICIIVA, Lam. 



Animal long, heliciform, tentacles slender, drooping, eyes at 

 their external base ; proboscis 

 truncated. Operculum non-spi- 

 ral, somewhat semioval, mem- 

 branous or testaceous. Shell 

 heliciform, turbinate, globose or 

 depressed, base callous around 

 the columella, which is some- 

 what flattened, and rather straight ; aperture tri- 



