1246 DU'IOnON 



and of various shades of green, showing the closest relation- 

 ship with many of the forms on the west side of the Andes. 

 The older shells often have the dorsal and ventral lines al- 

 most parallel and a decidedly bronzy epidermis much like that 

 of D. auratns. 



This species was received from von Ihering under this name, 

 but, so far as I have been able to ascertain, it has never been 

 published. 



DiPi,oi)ON WAGNERiANUS Simpson. 



"Shell ovate-oblong, ventral margin slightly incurved ; trans- 

 versely sulcate, anterior end roundly attenuate, posterior nar- 

 row and rounded. Hinge consisting of one, heavy/ crenulate 

 and sometimes bifid cardinal tooth and two, compressed, elon- 

 gate laterals in the right valve and two crenulate cardinals and 

 a single, very long, very thin, crenulate lateral in the left. Beaks 

 incurved, in young specimens with simple, longitudinal folds, 

 in the adults eroded. Umbones plano-convex, not rugose. 

 Margins acute, simple. Cavity smooth, shining, pearly. Epi- 

 dermis olive-brown, nacre bluish. 



Length 2.1, height i inch." (Wagner). 



Type locality, Rio Sao Francesco, Brazil. 

 Unio ellipticus Wagner, Test. Fluv. Bras., 1827, p. ^;^, pi. xxu, 



figs. I, 2. — KusTKR, Conch. Icon. Unio, 1861, p. 238, pi. hxxx, 



fig. 2. — SowKRRY, Conch. Icon., X\T, 1868, pi. lxxiv, fig. 



382. 

 Margaron (Unio) ellipticiis Lra, Syn., 1852, p. 21 ; 1870, p. 31. 

 f Diplodon zvagnerianiim Simpson, Syn., igoo, p. 877. 



Barnes applied the name Unio ellipticus in 1823 to a species 

 which is believed to be ligamcntina. Wagner placed his shell 

 in Unio in the text, but Spix called it Diplodon cllipticmn in 

 the plate. 



Var. santaniis von Ihering. 



"Mr. Garbe collected numerous examples in the Rio Santa 

 Maria, a tributary of the Rio Doce. The largest measures 42 

 mm. in length. The ventral margin runs nearly straight from 

 the upper anterior end in a posterior and downward direction 



