198 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



as the shell, the anterior part carrying six radiating minute teeth, the posterior 

 part eight, which are somewhat more nearly horizontal ; interior of the valve 

 smooth, whitish, margins entire. Alt. 6 ; lat. of shell, 6 ; of hinge line, 5 ; max. 

 diam. 4 mm. 



U. S. S. "Albatross," station, 3392, Gnlf of Panama, in 1270 fathoms, hard 

 bottom, temperature 36°.4 F. U. S. N. Mus. 122,876. 



Quite similar to the variety orbiculata of the Area pertuncuIoideSf but less ex- 

 tended laterally, less oblique, and with a finer ;iui more delicate sculpture. 



Area (Bathyarca corpulenta var. ?) pompholyx Dall. 



Cf. Area (Barhatia) corpulenta Smith, Challenger Rep., 1885, 13 (bivalves), 

 p. 263, pi 17, figs. 5-5b. 



Smith's Area corpulenta ranged from North Australia to Juan Fernandez 

 Island, and on the west, northward to Celebes, in 200 to 2-125 fatlioms, thus cov- 

 ering part of the range of the present shell, which differs from Smith's very full 

 and careful description of A. corpulenta'wx the following particulars : The beaks are 

 larger, fuller, and more conspicuous ; the sculpture is composed of narrow, fiat, 

 sniootli, concentric bands much wider than the radiating lirae, which are only vis- 

 ible in the interspaces and do not nodulate the intersections; in comparing an 

 umbonal view of the present shell with the figure in the Challenger Report, the 

 beaks of tlie specimen are much nearer the anterior end of the hinge line than in 

 the figure. These lead me to tliiuk that the two may be distinct, or at least dis- 

 tinguishable varieties, as the specimens I liave seen show variations. The present 

 shell measures 23.5 mm. long; 26 high; diameter 22; hinge line 16.5, with 

 the beaks 4.5 mm. from the anterior end of the hinge line. The hinge in this 

 specimen has seven anterior and five posterior teeth with an edentulous gap 

 10 mm. long between them, but another specimen of the same species has the 

 entire hinge line denticulate. The stations are as follows : 



Barbatia Gkay. 



CUCULLARIA Conkad. 



Cucullnriii Conrad, Amer. Journ. Conch., 1869, 5 p. 97 ; type, Area heterodonta Des- 

 liayes. Eocene. 



I pointed out in 1898 that the forms included by Conrad in his genus Cucul- 

 laria were probably not closely related to Macrodon Lycett, to which tiieir hinges 



