﻿NKPHRONAIAS 



277 



I have never seen this species, which seems to be distin- 

 g^uished from other members of its group by being- higher in 

 proportion to its length. \on Martens" figures, 10 and 11, 

 represent male specimens. His fig. q is probably taken from 

 a young shell. 



Nkphron.\ias rugui.osa (Charpentier in Kuster). 



Shell oblong, rhomboid, compressed or subconipressed, solid, 

 quite inequilateral, covered with close, distinct, concentric fur- 

 rows ; beaks rather high, their sculpture not observed; epider- 

 mis olivaceous or greenish-brown, often with hairlike, green- 

 ish rays over the disk and one or more broader, distinct green 

 and yellow rays on the posterior slope : pseudocardinals large, 

 solid and ragged ; laterals straight : muscle scars well im- 

 pressed : dorsal scars deep and numerous, extending from the 

 center of the cavity along the base of the pseudocardinals ; 

 cavity of the .shell shallow ; nacre rich purple. The figures of 

 the two shells, which I refer to this species, are evidently 

 taken from male shells and are nearly straight on the base. 

 The lower end of the biangulation behind reaches nearly to the 

 base of the shell. 



Length 52. height 28. diam. 14 mm. 



Mexico or Central America probably. 

 Unio rngiilosns Charpentier in Kuster, Conch. Cab. Unio, 



1856, p. 154, pi. xLiv, fig. 5. 

 Ncphronaias riigulosiis Simpson, Syn., iqoo, p. 596. i 



The locality, "New Holland," given in Kuster for this spe- 

 cies is undoubtedly erroneous. It is evidently Mexican or 

 Central American, and is. no doubt, a male shell of a species 

 of Nephronaias. I have not seen authentic specimens of either 

 this or Unio persulcatiis Lea. but the two are certainly very 

 close to each other. 



Nephrgnaias persulcata (Lea). 



Shell long rhomboid, rather compressed, svibsolid with a 

 low, rounded posterior ridge, which ends in a scarcely percep- 

 table biangulation behind, covered throughout with close, fine, 



