ANODONTITES 1449 



truncate or snbtrnncate above, rounded below ; posterior ridge 

 full, rounded ; surface rough, usually with rude, irregular 

 growth lines, covered with a thick, dirty olive or brown epi- 

 dermis, which sometimes is feebly rayed ; nacre lurid, bluish 

 or greenish, thicker in front ; muscle scars large, impressed ; 

 prismatic border wide. 



Length 83. height 46, diam. 37 mm. 



Length 80, height 48, diam. 30 mm. 



Brazil, Ecuador, Peru; south to Argentina. 

 Anodonta tenehrkosa Lka, Tr. Am. Phil. Soc, V, 1834, p. 78, 



pi. XII, fig. 36; Obs., L 1834. p. 190, pi. XII, fig. 36. — Chenu, 



Man., 1850, p. 146, p. 720. 

 Margarita (Anodonta) tenehrkosa Lka, Syn., 1836, p. 54; 



1838, p. 2>^. 

 Anodon tenehricosa vSowerby, Conch. Icon., XVII, 1867, P^- 



XIII, fig. 43. 

 Margaron (Anodonta) tenehricosa Lea, Syn., 1852, p. 53; 



1870, p. 83. 

 Glabaris tenehricosa von Ihering, Arch, fiir Nat., 1893, p. 61. 

 Anodon tenehricosus Sowerby, Conch. Icon., XVII, 1870, pi. 



XXXI, fig. 123. 

 Glaharis tenehricosus Simpson, Syn., 1900, p. 930. 



A rough, dull-colored, unattractive species, which, when old, 

 usually has the shell much eroded. The border outside the 

 pallial line is wide, and in old specimens the pallial line is gen- 

 erally impressed and crenate. 



Anodontites pastas anus (Clessin). 



Shell rather short, rhomboid, moderately inflated, subsolid, 

 subrugose, lightly, undulately striate, somewhat inequilateral ; 

 beaks full and elevated ; hinge line arched ; base incurved me- 

 dially so that the shell is a little arcuate ; anterior end rounded ; 

 posterior end obliquely truncate above, rounded below ; epider- 

 mis dark fuscous : nacre whitish. 



L.ength 69, height 37, diam. 26 mm. 



Rio Pastasa. Ecuador. 

 Anodonta pastasana Clessin, Mai. Bl. (2), I, 1879, p. 173, pi. 



XI, fig. I. 

 Glaharis pastasaniis Simpson, Syn., 1900, p. 930. 



