64 ONCIDIOPSIS. 



Subgenus MARSENINA, Gray, 1850. 

 L. RHOMBICA, Dall. PI. 26, figs. 24, 25. 



Pure white, subrhomboidal, moderately elevated, whorls 3 ; 

 columella thickened, stout, with a groove behind the callus ; 

 whorl appressed against and slightly flattened below the suture ; 

 spire very small, not elevated ; aperture subquadrate, outer lip 

 very much produced above and below, suture deep ; surface 

 smooth. Length, 12 mill. 



Monterey, Cal. 



Animal bluish translucent, white, the mantle only partially 

 covering the shell. Untigured. 



L. GLABRA, Couthouy. PL 26, figs. 26-28. 



Thin, pellucid, white, smooth and shining, whorls two, the first 

 a mere nucleus, the aperture oval, very large. Length, 12 mill. 



New England to Greenland, Norway. 



It is L. halioloidea, Gould, not Linn.; L. micrompliala, Bergh, 

 (figs. 27, 28). 



L. GRCENLANDICA, Holier. PL 26, figs. 29, 30. 



Obliquely elevated, whorls 2, the last very large, whitish, 

 shining. Length, 8 mill. 



Greenland, Norway. 

 L. PRODITA, Loven. PL 27, figs. 31, 32. 



More obliquely elevated than the preceding species, with 

 deeper suture, but perhaps only a variety of it. 



Maine to Greenland. 

 L. AMPLA, Verrill. PL 27, figs. 33, 34. 



Inflated, subglobular, the spire not elevated. 



Eastport, Maine. 



Genus ONCIDIOPSIS (Beck), Bergh, 1853. 



0. GLACIALIS, Sars. PL 26, figs. 35, 36. 



Shell thin, hyaline, slipper-shaped, flexible. Length, 16 mill. 

 Animal with a long, narrow foot ; the mantle subverrucose, ash- 

 colored, maculated with brown. 



Norway, 



