400 PROCEEDINGS OF THE NATIONAL MUSEUM. vouxxvi. 



Shell oval, quite inequilateral, when fresh of an olive-green or rich 

 olive-l)rown color, l>leaching- on the beach to cream color, with regular, 

 rather distant concentric sulci; subcompressed, sometime almost ros- 

 trate behind. Maximum length, 38.0; diameter, 13.5 mm. 



The 3^oiuig are ver}" like the adult Z. Jluctuosa Gould, of the boreal 

 Atlantic. ])ut have a deeper pallial sinus. 



LIOCYMA SCAMMONI Dall, 1871. 



Port Simpson, British Columbia, Scammon. 



Brown, dark, solid, with heavy hinge and strong, prominent liga- 

 ment. The umbones are more central and the pallial sinus more 

 shallow than in any other species. Maximum length, 24.0; diameter, 

 11.. 5 mm. 



VENERUPIS LAMELLIFERA Conrad, 1837. 



Farallones Islands, oft" San Francisco Bay, and soutli to Lower 

 California. 



This ver}^ irregular species has obsolete radial and often very strong, 

 distant, concentric lamellae, though under favorable conditions, espe- 

 cially in adolescent specimens, the lamelh\? may be thin and sharp. 

 The young are brightly colored, the adults dull and earthy, though 

 toward the southern extreme of its range the shell becomes more 

 porcellanous. It was described as Yerius JaiiieUlfera by Conrad, and 

 Petricola cordlerl Deshayes, 1839, is synonymous. It has been gener- 

 ally known as Rupellaria lamellifera., as determined by Carpenter. 



VENERUPIS FOLIACEA Deshayes, 1853. 



Cape St. Lucas, the Gulf of California, and southward to Acapulco 

 and the Bay of Panama. 



A short and foliaceous species, more or less stained with purple. 

 Ta2Jes squamosa Carpenter, 1857, from Mazatlan, is the nepionic young 

 of this species. Venerupis jpaupercula Deshayes, 1853, if nnilly from 

 Mazatlan, is perhaps identical, and Venus troglodytes Morch, 1861, is 

 certainly synonymous. 



VENERUPIS OBLONGA Sowerby, 1834. 



Bay of Panama to Payta, Peru. 



Yenrriiplsfim'brlata Sowerby, 1853, is prol)ably synonymous; T. ellip- 

 tica and Y. solida Sowerby, 1831, ])elong in the genus Petricola, where 

 Sowerby originally placed them, and not in Venerupis, to which they 

 w-ere referred by Deshayes. The relations of V oUonga to V. foUacea 

 are in need of elucidation. 



