136 THE NAUTILUS. 



U. excavata vs. satur. These two are the same species ' 

 U. satur is not, strictly speaking, a variety of ventricosa, but be- 

 cause of priority it is a good species, and excavata becomes a syn- 

 onym! 



U. claihornensis vs. hydiana. The greatest difiFerence existing here 

 is the lack of rays in claihornensis. 



U. beadleana, ) ^,^ ^gkewii. These three species are identical, 



U. chickasawensis ) 

 the varietal differences being no more than the different hab'tats 

 should demand. 



Proptera inflata vs. amphichxna. A suspicious piece of evi- 

 dence is to be noted in the fact that where one of these species is 

 found, there is a lack of P. Icevissima J 



However, amphichcena has no wing, even when young and per- 

 fect. 



TJ. refulgens and sphsericus. These two species are identical and 

 form a well-marked subspecies characterized by purple nacre. 



U. ebentis and crassidens do not grow in the Sabine. 



Margaritana complanata is by this find considerably extended 

 down South. They were gravid when taken in November. 



PLANORBIS BICAEINATUS AND PLEURODONTE ANGULATA. 



BY E. G. VANATTA. 



Some recent studies have shown that the nomenclature of these 

 species is somewhat intricate, and an examination into their history 

 proves that the names in current use cannot be held. 



The records bearing on the question follow. 

 Planorbis bicarinatus Lamarck. 



In the Ann. du Mus. Hist. Nat. Paris V, p. 36, 1804, La- 

 marck describes a fossil under the name Planorbis bicarinata, which 

 was figured on plate 62, fig. 3 of the Annales du Museum viii, 1806. 

 It was also described in Animaux sans Vertebres Supp., vii, p. 542, 

 1822. Deshayes in the Anim. s. Vert. Bassin, Paris, ii, p. 438,. 

 1864, placed this species in Adeorbis. 



Planorbis bicarinatus Say (not Lam.) 



In the Third American Edition of Nicholson's British Encyclo- 

 pedia, Philadelphia, 1819, Conchology, pi. 1, f. 4, Say, described 



