58 THE NAUTILUS. 



cation was correct, since Rafinesque' s shell came from the Ohio 

 drainage, and these Hyde shells from the Atlantic drainage. In 

 case these latter should prove distinct Conrad proposed the 

 name Unio subviridis. In the following year Dr. Lea published 

 the same shell under the name of tappanianus, but in the mean- 

 time Conrad had published the shell a second time (Monography 

 of Unionidse, 1836) as viridis (Rafinesque). Dr. Lea up to his 

 death, claimed the shell, on the ground that it was not viridis 

 Rafinesque, and that Conrad's name viridis was a synonym. 



Conrad, on his part, persisted that his identification was cor- 

 rect, because a single valve of this shell in Mr. Poulson's collec- 

 tion had been labeled viridis by Rafinesque. The confusion 

 thus wrought, is now eighty years old. 



Rafinesque, in 1820, described very clearly a shell from the 

 Ohio drainage, under the name of viridis, which Dr. Lea (as he 

 freguently did} redescribed several years later, under the name 

 of compressa. In 1831, Rafinesque labeled for Mr. Poulson, a 

 single valve of a shell under the name viridis which valve Conrad 

 stated was identical with the Hyde shells. It is worthy of note, 

 that if this valve was not correctly named by Rafinesque, it was 

 an exceedingly close guess, as the two species are so close that they 

 are often confounded yet. That Dr. Lea was so positive that 

 this label was incorrect, proves conclusively that Lea was fully 

 aware that the true viridis of Rafinesque was the compressa, (or 

 pressus) of Lea. Of course, Lea was too "cute" to call atten- 

 tion to this fact, since he would then lose this name also, nor 

 did he have generosity enough to give the Hyde shells to Conrad 

 under the name subviridis, of which he was fully cognizant. 



Subviridis Conrad was elegantly figured on plate 9, in an ap- 

 pendix to "New Fresh Water Shells." The appendix is dated 

 1835, and was only bound in a few copies of the book, and this 

 accounts for the total omission of the name, or plate, by Mr. C. 

 T. Simpson, and other authors. The correct synonymy of these 

 two species therefore (omitting some unimportant names) is as 

 follows 



LASMIGONA SUBVIRIDIS (Conrad). 



Unio viridis? Conrad, 1835, New Fresh Water Shells, appen- 

 dix, plate 9, Fig. 1, or subviridis Conrad, if new. 



