274 BULLETIN OF THE 



A single specimen was obtained living, at Station 236, off Bequia, in 1591 

 fms., fine ooze, bottom temperature 39°. F. 



The specimen agrees well in every way with Mr. Smith's descriptions and 

 figures. 



Callocardia (Vesicomya) pilula Dall. 



Diplodonta pilula Dall, Bull. M. C. Z., IX. p. 136, 1881. 

 Plate VIII. Fis. 13. 



Habitat. Station 43, 339 fms., one specimen. 



This little shell when submitted to higher powers, and especially when com- 

 pared with the V. atlantica, was recognized as a Vesicomya. Its very minute 

 size and the difficulty of opening it without breaking it led to its reference in 

 the preliminary work to Diplodonta, while the doubt attending the reference 

 was at the same time expressed. I am of the opinion that it is really a young 

 specimen of the species afterward named atlantica by Mr. Smith, but I do not 

 feel certain of it. Should it turn out to be so, I should prefer to waive my 

 name in favor of Mr. Smith's, for the reason that there was not information 

 enough in my description to enable any one to recognize it as a Vesicomya. 



Callocardia (Vesicomya) venusta, n. s. 



Shell pale straw-color, elongate-ovoid, inflated, equivalve, inequilateral, thin, 

 chalky in consistency, fragile ; beaks full, near but not torching each other, 

 lunula large, marked by a sharply cut groove or line ; outer surface polished, 

 uniformly concentrically sculptured with fine not very regular wrinkles ; in- 

 terior polished ; anterior scar high, rather narrow, rounded below and pointed 

 above ; posterior scar much shorter, rounder and broader; pedal scar small, 

 round, strongly marked, under the anterior tooth; hinge that of the subgenus, 

 teeth flat and thin, the anterior cardinal of the left valve the larger, its edge 

 waved ; inside margin of the valves, close to the edge, sculptured with a few 

 not quite parallel sharp grooves, much as in Transennella ; anterior ends of the 

 valves rounded, posterior more pointed especially toward the lower posterior 

 part of the margin. Max. Ion. of shell 19.0; max. alt. 14.0: double diameter 

 of largest valve 11.5 mm. 



Habitat. One valve dredged at Station 1, in 801 fms., mud, bottom temper- 

 ature 39°.5 F., off Havana. Also several valves by the U. S. Fish Commission 

 at Station 2678, in 731 fms., oflf Cape Fear, North Carolina, bottom temperature 

 38°.7 F. 



The presence of a very young valve shows that the elongated shape is con- 

 stant. The shell in shape a good deal resembles Meiocardia Agassizii, but the 

 sculpture is less regular, there are no lateral teeth or radiating keels or ridges, 

 and the substance of the shell is more earthy. 



