SO AMERICAN MARINE CONCHOLOGY. 



1. R. eburnea, Stimpson. Fig. 164. 



(Rissoa.) Proc. Bost. Soc. Nat. Hist. iv. 14. 1851. 



Shell small, ovate-conoid, white, shining, smooth ; whorls four, 



rather convex, subangulatecl at the suture ; aperture ovate-elliptic ; 



peristome thin, simple, acute, effuse anteriorly. 



Length 4.5, diam. 2.2 mill. 



• Massachusetts. 



2. R. stjlcosa, Mighels. Fig. 165. 



(Phasianella.) Bost. Journ. Nat. Hist. iv. 348, t. 1G, f. 4. 1843. 

 Shell very small, ovate-conical, smooth and white; whorls four, 

 slightly convex, with six or seven transverse grooves on the body- 

 whorl, and three on each of the two next above, spire smooth and 

 pointed ; aperture ovate-oblong, with three slightly apparent trans- 

 verse bands within, as seen under a strong magnifying power. 



Length 2.5, diam. 1.3 mill. 



Maine. 



Genus SKENEA, Fleming. 



Hist. Brit. Anim. 297, 313. 1828. 



1. S. planorbis, Fabricius. Fig. 166. 

 {Turbo.) Fauna Grcenl. 394. 1780. 

 Shell minute, flat, slightty convex above, broadly concave below, 

 with a perspective umbilicus ; whorls three, smooth, light horn- 

 color; aperture small, circular, with sharp lip. Operculum multi- 

 spiral, horny. 



Height .8, diam. 1.2 mill. 



Clinging to stones at low-water mark. 



Mass., northwards. (N. Europe.) 



Genus COCHLIOLEPIS, Stimpson. 

 Bost. Proc. vi., 308. 1858. 

 1. C. parasiticus, Stimpson. Fig. 167. 

 Bost. Proc. vi., 308. 1858. 

 Shell thin, discoidal, convex above, concave and umbilicated 

 below; the edge thin and sharp; whorls three, rapidly enlarging; 

 surface smooth and glossy ; lip not thickened. Operculum thin, 

 flexible and pellucid. 



Animal blood red ; foot oblong, tapering behind, and slightly 

 emarginate in front; head small, rounded, with long, slender, 

 tapering tentacles. Eyes none? 



Parasitic on Acoetes lupina. 



Charleston, 8. C. 



