432 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



Challenger Expedition, Station 305, west coast of Patagonia, in 165 fathoms, 

 mud. 



U. S. S. " Albatross," station 2792, off Manta, Ecuador, iu 401 fathoms, mud, 

 bottom temperature 43° F. U. S. N. Mus. 95,418. Also at station 2780, 2781, 

 and 2782, southern coast of Chile, in 258 to 369 fathoms, mud, temperatures 

 47° to 50°; and a broken specimen, probably of this species, at station 3360, in 

 1672 fathoms, saud. Gulf of Panama, temperature 42° F. 



This widely distributed species is somewhat notable for its long, slender, and 

 twisted rostrum, which is smaller in caliber, considering its length, than that of 

 any other of the large species yet made known. 



Cuspidaria panamensis Dall, n. sp. 



Plate 16, flgire 2. 



Shell large, inflated, rostrate, equivalve, subequilateral, white, covered with a 

 yellowish-brown periostracum, paler toward the middle of the disk ; surface 

 sculptured only with lines of growth ; rostrum small, short, somewhat recurved, 

 gapiug at the extremity; beaks inflated, high, opisthogvrate ; luuule none, but 

 a long, lanceolate, iuipressed, smooth escutcheon, the larger part of which is in 

 the left valve ; form as figured ; interior white, the hinge as usual ; in the right 

 valve the hgamentary nymph (which is distinct from the resiliifer), is so promi- 

 nent as to appear like a tooth ; there is no palhal sinus. Lon. 42 ; alt. 25 ; 

 diam. 23 mm. There is a small lithodesma. 



U. S. S. " Albatross," station 3394, in the Gulf of Panama, in 511 fathoms, 

 mud, bottom temperature, 41°.8 F. U. S. N. Mus. 122,937. 



A large species, not in general unlike C glacialit Sars, but with a smaller, 

 more distinctly defined and proximally constricted rostrum. 



Cuspidaria (Cardiomya) pseustes Dall, n ep. 



Shell large for the genus, rostrate, inflatetl, nearly equivalve, inequilateral, 

 whitish, with a thin, greeuish-gray periostracum ; beaks rather low, but full, dis- 

 tinct, situated in advance of the middle of the shell, and separated by a long, 

 narrow, longitudinally faintly striated, amphidetic, impressed area, wider behind 

 the beaks; anterior dorsal margin straight, abruptly declining to the rotundity 

 of the anterior end; base evenly arcuate; posterior dorsal slope slightly cou- 

 cavely arcuate as the rostrum recurves a little ; end of the rostrum gapiug and 

 roundly truncate; surface radially very finely threaded above, crossed by con- 

 centric wrinkles of the periostracum ; proximal end of the rostrum somewhat 

 constricted ; disk radially threaded, the threads rounded, with wider interspaces 

 and occasional more sh'uder intercalary threads; the major threads near the 

 middle of the base are about one millimeter apart ; interior whitish, the sculpture 

 reflected by grooves corresponding to the external ridges ; hinge normal ; interior 



