1895. PROCEEDINGS OF THE NATIONAL MUSEUM. 17 



U. S. Fisli Commission station 2770, off Spiring Bay, Argentine coast- 

 attached to seaweed dredged in 58 fathoms. 



Tijpc.—^o. 97057, U. S. N. M. 



This little species is interesting as being the first marine Pelecypod 

 in which the existence of a glocliidiuni stage was recognized. An exam- 

 ination of P. setosa^ Carpenter, from Cape St. Lucas shows that it agrees 

 in this particular. The genus was originally named BryojjMla, which 

 proved to be preoccupied, and was changed to Philohrya.^ The geiuis 

 is apparently related to Fteria, rather than to Finna, as supposed by 

 Carpenter. 



CALLOCARDIA STEARNSII, Dall. 

 Callocardia sicarnsii, Dall, Proc. U. S. Nat. Mus., XVII, p. 693, fig. lA, 1895. 



Shell closely resembling C. ( Vesicomija) venusta, Dall, but larger, less 

 intiated, the anterior end higher, the base more rounded, and the pos- 

 terior end more angukT.r and pro])ortional]y longer. Internally the 

 flexure in the pallial line below the posterior adductor scar is more 

 marked, and the ligament and also the posterior tooth in the right valve 

 are conspicuously shorter. C. stearnsii has the same pale straw-colored 

 epidermis and feeble incremental sculpture as C. venusta, but the iunuie 

 is narrower and the line circumscribing it less impressed. Height, 1 7.5 ; 

 length, 25; diameter, 11.5 mm.; the vertical of the beaks is behind the 

 anterior end about 7 mm. 



Off the coast of Washington, near Tillamook, at U. S. Fish Commis- 

 sion station 334(3, in 780 fathoms, mud; temperature, 37.3° F. 



This genus is remarkable for its subfoliobrauchiate gills, so xevj dif- 

 ferent from the loosely reticulate branchia of the shallow- water Iso- 

 cardia, with which until recently CaUoeardia was associated as a mere 

 subgenus. These are described in the paper to which reference is made 

 above, but, the species having been only named in manuscript at that 

 time, it w^as thought best to add the present description. 



CALLOCARDIA LEPTA, new species. 



Shell large, thin, earthy, white, compressed, with an olivaceous or yel- 

 lowish, dehiscent epidermis, with concentric wrinkles and projecting, 

 lamiuic, which in the young are somewhat regularly spaced and dis- 

 tant, in the adult crowded and irregular ; beaks small, low, not conspicu- 

 ous, moderately intiated; valves evenly arcuate below, rounded at both 

 extremities, the anterior shorter and less high than the posterior; lunule 

 narrow, long, bounded by an incised line; ligament external, long, set 

 in a groove, with the escutcheon narrow, its edges elevated above the 

 dorsal margins of the valves and obtusely keeled, extending one-half 

 longer backward than the length of the ligament; interior smooth, or 



' Smithsonian Miscellaneous Collectious, X, No. 252, MoIIusks of Western Nortb 

 America, by P. P. Carpenter, index, p. 21, December, 1872. 



Proc. N'. M. J»5 2 



