114 BULLETIN OF THE 



lamellsD are separated by pretty uniform spaces marked ^\^th extremely fine 

 and rather irregular lines of growth ; there are no radiating ribs, but on the 

 transversely sculptured rostral area the laniellai fail and are replaced by 

 densely crowded, rather irregular and extremely fine wrinkles ; anterior cardi- 

 nal margin arched ; posterior cardinal margin oblique, nearly straight ; anterior 

 and basal margin rounded, with a strong sharp flexuosity differentiating the 

 rostral part, which is also correspondingly compressed as compared with the 

 inflated anterior part ; rostrum short, rounded at the end, not recurved ; umbo 

 prominent ; interior smooth, with grooves corresponding to the lamellse ; mar- 

 gins thin, sliarp ; ligamentary fossette long, extremely narrow, reduced to a 

 mere line parallel with, the margin from which a barely perceptible corner 

 projects inward. Lon. 12.5, of which 6.75 is posterior to the line of the 

 umbo ; alt. 8.0 ; approximate diam. 6.25 mm. 



Station 36, 84 fms., one right valve. 



This also agrees with none of the described species so far as I have been 

 able to discover, and is a particularly well marked form if the limited mate- 

 rial be a fair representative of the usual characters of the species. 



Corbula cubaniana D'Orbignt. 



C. cubaniana D'Orbigny, Sagra, Moll. Cub., II. p. 282, Tab. XXVI. figs. 51-54 



(1846). 



Sigsbee, off Havana, in 100 fms. ; one valve probably of this species. 



Corbula Barrattiana C B. Adams. 

 C. Barrattiana C. B. Adams, Contr. to Conch., p. 237, 1852. 



Off the west coast of Florida, in 30 fms. ; Station 21, 287 fms. 

 Two specimens probably of the above unfigured species. 



Corbula Swiftiana C. B. Adams. 



C. Swiftiana, C. B. Adams, Contr. to Conch., p. 236, 1852. 



Sigsbee, off Havana, in 182 and 450 fms. ; off Sombrero, in 72 fms. 

 Specimens agreeing with Adams' diagnosis of his hitherto unfigured species 

 were obtained in some numbers, especially at the first locality. 



Corbula Dietziana C. B. Adams. 



C. Dietziana C. B. Adams, Contr. to Conch., p. 235, 1852. 



Off the west coast of Florida, 30 fms. ; off Sombrero, 72 fms. ; Barbados, 

 100 fms. ; Gordon Key, 68 fms. 



