MUSEUM OF COMPARATIVE ZOOLOGY. 245 



Area (Bo/rhatia) pteroessa E. A. Smith seems very similar externally to our 

 shell, but the hinge is diflferent and the shell more produced behind ; the 

 manner in. which the black ligament is placed would seem to be similar in 

 both. 



An allied species with an outline almost precisely similar to A. culebrensis 

 Smith (Chall. Rep., pi. xvii. fig. 9 a) was obtained (a single valve) N. W. of 

 the N. W. end of Cuba in 80 fms. by the U. S. steamer " Albatross " in 1885. 

 It has a hinge much like that of 31. asperula, but its external surface is 

 entirely different; there are numerous concentric grooves, with wider inter- 

 spaces covered everywhere with an oblique shagreened ornamentation ; beside 

 this there are obsolete radiating series of minute scales, probably stronger in 

 some specimens, and on and behind the ridge from the umbo to the posterior 

 angle of the margin are four well defined and two or three obsolete nodulous 

 radii. The valve is about six millimeters long and quite inflated ; the um- 

 bones must nearly touch in perfect specimens, as the area is extremely narrow 

 and the beak well developed. It may take the name of M. sagrinata. 



Professor Yerrill's Area profundicola, though not very characteristically 

 figured, is, from a typical specimen, more finely striated, the lower posterior 

 region less patulous and its hinge margin not so high. The front teeth are 

 more, and the hind teeth less, oblique than in Macrodon. It may be observed 

 that the gap between Macrodon and certain forms of Barbatia is not very wide. 



Family NUCULID^. 

 Genus NUCULA Lamarck. 



Nucula Lamarck, Prodrome d'une Nouv. cl. des Coquilles, p. 87, no. 104, 1799. 



Type Area nucleus, L. 

 NxKulana Link, Beschr. Rost. Samml., p. 155, 1807. 



I take this opportunity of mentioning, for students who cannot get access to 

 the rare work of Link, that his Nuculana is an exact synonym of Nucula 

 Lamarck, and was intended merely as a modification of that word; while the 

 diagnosis, " shell smooth, closed all round," will not apply to the group sepa- 

 rated by Schumacher, afterward, under the name of Leda. That the only 

 species of the group in the collection was N. rostrata was merely an accident, 

 and it was evidently not intended as a type, for it does not agree with his 

 diagnosis. 



