GASTEEOPODA. 463 



SMI conic, few- whirled, epidermis green ; aperture oblique, peristome 

 abruptly reflected ; operculum claw-like. The typical species appear to be 

 MelaniaddB, but some small shells like HydroUa have been included in the 

 genus. 



ViTEiNELLA (valvatoides). C. B. Adams, 1850. Shell minute, hyaline, 

 turbiniform, umbilicated ; aperture large, orbicular. Bistr, 18 sp. W.In- 

 dies (5), Panama. 



ScissuRELLA (crispata). Animal like Margarita; tentacles long, 

 pectinated, with the eyes at their base ; foot with two pointed lappets and 

 two long slender pectinated cirri on 

 each side ; operculum ovate, very thin, with 

 an obscure sub-spiral nucleus. 



No part of the animal was external to 

 the shell. The only living example occurred 

 at Hammerfest, in 40-80 fm. water; when 

 placed in a glass of sea- water it crawled up 

 the side and scraped the glass with its 

 tongue. It was pale and translucent when 

 living, but turned inky black after immer- 

 sion in alcohol. {Barrett, An. N. H. 17, Fig. 261. SHssm-ella. -f- 

 p. 206.) 



Mr. Jeffreys found S. ehgans, D'Orb. plentifully alive in sea-weed on the 

 coast of Piedmont. It has a multispiral operculum, like Margarita. In 

 this species, as noticed by Mr. G. Sowerby, the slit in the pedstome of the 

 young shell is converted into a foramen in the adult, as in the Jurassic 

 Trochotoma. 



Catantostoma (clathratum) Sandberger, 1842. Shell \<ktTleurotomaria; 

 last whirl deflected, peristome incomplete, slightly varicose, irregular. 

 Fossil. Devonian, Eifel. 



Raphistoma (angulata). Hall, (p. 147). L, Silurian. U. States. Canada. 

 Shell depressed, out lip sinuated. In R. compacta (Salter) the spire is sunk 

 and basin-shaped, the umbilical side flat, and the last whirl a little disunited. 



Holopea (symmetrica). Hall. 1847. (lanthinidre ?) Outer lip sinu- 

 ated near the base. L. Silurian, New York. 



Brownia (Candei) D'Orb. 1853. (Atlantidse ?) A minute discoidal shell, 

 associated with Helicophlegvia in the first instance, but distinguished by the 

 serrated keels on its whirls, and lateral notches to the aperture. Cuba. 



Calcarella (spinosa) Souleyet. 1850. (Atlantidse?) Shell sub-globose, 

 dextrally spiral, horny, pellucid, with three acutely seiTated keels ; aperture 

 thickened, entii-e. Lat. 3 lines. South Seas. (^ Echinospira, Krohn.) 



Recluzia, Petit, 1853. R. Jehennei, Red Sea. R. Rollandiana, Atlan- 

 tic, and Mazatlan. Animal pelagic, resembling lanthina ; one inch long. 

 Shell paludiniform, thin, with a brown epidermis ; whirls ventricose ; aper- 



