712 PROCEEDINGS OF THE ACADEMY OF [Nov. , 



Calyptogena pacifica Ball, 1891. 



Clarence Strait, Alaska, in 322 fathoms, muddy bottom, tem- 

 perature 42.4° F. ; U. S. Fish Commission steamer " Albatross." 

 Also fossil in the Pliocene of Los Angeles, Cal. 



An oblong, heavy, dull and chalky shell ^vith no radial sculpture 

 and with a grayish-green periostracum over a nearly smooth 

 surface. 



Milneria minima Dall, 1871. 



Monterey, Cal, south to Cerros Island, Lower California, usually 

 nestling on the backs of the shells of Haliotis. 



Originally described as Ceropsis minima, the generic name being 

 preoccupied, was changed to Milneria in 1881. A minute, tra- 

 pezoidal white shell, of which the females have a dome-shaped 

 indentation on the ventral surface lined and closed by an extension 

 of the mantle, in which the young are incubated. It is figured 

 in Proc. U. S. Nat. 3Ius., VIII, PL XXIV, figs. 4 to 7, and also 

 in Fischer's Manual. 



Carditella pallida E. A. Smith, iS9l. 



Port Rosario, Western Patagonia, in 2 to 30 fathoms. 



A small fan-shaped whitish shell with an internal resilium and 

 12 to 15 strong radial ribs. There is a small external ligament. 

 Carditella semen Reeve, 1813. 



Off Mexillones, Atacama Desert, Bolivia, in three fathoms, 

 Cuming. 



Ovate, olive-brown, with flattish ribs, very minute. 



Carditella tegulata Reeve, 1843. 



^^alparaiso, Chile, in 25 fathoms, Cuming. 



Said by Smith to differ from C. pallida by being more inequi- 

 lateral, less triangular and has only twelve ribs. It is certainly 

 very closely allied. 



Carditopsis flabellum Reeve, 1843. 



Valparaiso, Chile, Cuming ; and the western part of the Straits 

 of Magellan, in 61 fathoms, bottom temperature 47.9°; U. S. Fish 

 Commission steamer " Albatross." 



Differs from C. pallida by the greater delicacy of the lateral 

 teeth, a larger resilium, and the absence of any external hgament, 

 according to Smith. 



