﻿300 OnOVARIA 



Mciriiaron ( UnioJ ellipsis Lica, Syn., 1852, p. 26; 1870, p. 41. 



Obozvria ellipsis Simi'Son. Syn., i<joo, p. 602. 



Unio triangularis Say, Am. Conch., VI, 1834. 



Unio olivarius Conrad, New F. W. Shells, 1834, p. 70. 



Unio taitianus Sowkkmy^ Concli. Icon., XYI, 1868, pi. lxvii, 



fig- 33^- 

 Unio pealei Lea, Pr. Ac. N. Sci. Phila., I, 1871, p. 191 ; Jl. Ac. 



N. Sci. Phila., VIII, 1874, p. 26, pi. viii. fi.i^. 23; Obs.. XIII, 



1874, p. 30, pi. VIII, fis- 23. 



Unio pealei Lea, of Kansas, is a little lighter colored than 

 the type and has the beaks a little farther from the anterior 

 end, but it does not seem to me to be worthy of even varietal 

 rank. 



Obovaria castanea (Lea). 



Shell rather small, that of the male ovate, that of the female 

 elliptical, inflated, solid, blackish-chestnut or olive-green, some- 

 times with faint, concentric, lighter and darker bands, occa- 

 sionally faintly rayed behind ; beaks fi>ll and high, placed near 

 the anterior end and marked with a few feeble, nearly parallel 

 ridges ; posterior ridge low ; left valve with two pseudocardi- 

 nals, the upper running nearly parallel with the two curved 

 laterals ; right valve with two pseudocardinals, with rarely a 

 third posterior one, the anterior tooth compressed, and a double 

 lateral ; beak cavities shallow : muscle scars small, impressed ; 

 nacre whitish or bluish white, iridescent and slightly thinner 

 behind. The male shell is ovate and pointed behind about mid- 

 way up from the base ; the female shell is elliptical, full at the 

 ]>ost-base, scarcely pointed behind, and in all cases I have seen 

 is much smaller than that of the male. 



Length (male) 40, height 2,2, diani. 2"/ mm. 



Length (female) 28, height 22, diam. 20 mm. 



Streams flowing into the Culf of Mexico, from the Alabama 

 River west to the Nechez. 



Type locality, Alabama River. 



