﻿SYMPHYNOTA 



487 



tial difference in the teeth or other characters. It is smaller 

 than charlottensis and rather more compressed, is lighter col- 

 ored and smoother. 

 SymphYxNOTa nf,glecta (Lea). 



Shell rhomboid, scarcely subsolid, convex, its greatest diam- 

 eter being about midway of the length, and from this point 

 it tapers regularly to the ends ; beaks rather full but not high; 

 posterior ridge double and angled; surface with delicate 

 growth lines; epidermis pale greenish-yellow with faint green 

 rays; left valve with two blurred pseudocardinals and two 

 remo'te, feeble laterals; right valve with one subcompressed 

 pseudocardinal and one well- developed lateral ; nacre whitish, 

 tinted purple, iridescent behind, slightly thicker in tront. 

 Length 50, height 30, diam. 19 mm. 

 Type locality. Northern Alabama. 

 Unio ncglectus Lea, Desc. 12 Uniones, 1843; Tr. Am. Phil. 

 Soc, IX, 1846, p. 280, pi. XLii, fig. 10; Obs., IV, 1848, p. 

 88, pi. XLii, fig. 10.— KusTER, Conch. Cab. Unio, 1861, p. 

 225, pi. LXXVI, fig. 4- 

 Margaron (Unio) neglectus Lea, Syn., 1852, p. 33; 1870. p. 



Symphynota ncglecta Simpson, Syn., k^oo, p. 004. 



' Has better developed teeth and a more decided double pos- 

 terior ridge than S. quadrata. The beak sculpture has not been 

 seen in either of these shells. 

 Symphynota quadrata (Lea). 



Shell rhomboid, scarcely subsolid, subcompressed, some- 

 what inequilateral, with slightly elevated, rather compressed 

 beaks, their sculpture not seen ; posterior ridge rounded ; sur- 

 face with decided concentric sculpture; epidermis brownish- 

 green with lighter and darker bands, slightly rayed and shin- 

 hig; left valve with an irregular, compressed, reflexed tooth 

 under the beak and a vestigial one in front of it; right valve 

 with a distinct, compressed pseudocardinal; laterals blurred 



