DIPLODON I 25 I 



generally more or less granose ; sometimes having wavy, 

 zigzag or chevron-shaped granular bars; occasionally it is 

 nearly smooth and shows traces of radial sculpture ; teeth del- 

 icate, compressed ; each valve with two pseudocardinals, the 

 posterior one in the left often nearly wanting ; two laterals in 

 the left valve and one in the right ; nacre whitish, often lurid 

 in the cavities, thicker in front. 



l^ength 50, height 26, diam. 15 mm. 



Length 58, height 35, diam. 19 mm. 



Length 58, height 28, diam. 18 mm. 



Length 39, height 21, diam. 14 nmi. 



Brazil : Guiana. 

 Unio granosa Bkugirrk, Jl. de Hist. Nat., L 1792, p. 107, pi. 



VI, figs. 3, 4.— Desiiayes, Enc. Meth., H, 1827, p. 151, pi. 



ccxLix, fig. 2. 

 Unio granosus Hani.ey, Biv. Shells, 1843, P- 182, pi. xxiii, 



fig. 21. 

 Margarita (Unio) granosus Lea, Syn., 1836, p. 17; 1838, p. 16. 

 Margaron (Unio) granosus Lea, Syn., 1852, p. 23 ; 1870, p. 34. 

 Diplodon granosus Simpson, Syn., 1900, p. 878. 

 Unio multutriaius Lp:a. Tr. Am. Phil. Soc, IV, 1831, p. 91, 



pi. XII, fig. 22: Obs., L 1834, p. loi. pi. XII, fig. 22. — Han- 



].EY, Biv. Shells, 1843, P- 176, pi. xx, fig. 35. — Chenu, 111. 



Conch., 1858, pi. XI, figs. 2, 2a, 2h. — Sowerby, Conch. Icon., 



XVI, 1868, pi. i,xxxv, fig. 455. 

 Margarita fUnio) multistriatus Lea, Syn., 1836, p. 13; 1838, 



p. 14. 

 Unio multisfriata d'ORiuGNY, V'oy. Am. Mer., 1843, P- 607. 

 Unio pfeiffcri Dunker, Zeits. fiir Mai.. V, 1848. p. 181. — 



PPEiFf^ER, Nov. Conch., II, 1866, p. 151, pi. xxxix, figs. 4-9. 

 Unio psammactimis Phiijppt, Conch., III. 1848, p. 79. pi. v, 



fig'- 2. — KusTER, Conch. Cab. Unio, i8s6, p. ic;9. pi. xlv, 



fig. 6. 

 Unio famelicus Goui.d, Pr. Bost. Soc. N. H., Ill, 1850, p. 294; 



U. S. Expl. Exp., XII, 1852, p. 432, figs. 544a, 544&. — Sow'- 



ERBY, Conch. Icon., XVI, 1868. pi. lxxv, fig. 391. 

 Margaron (Unio) famelicus Lea; Syn., 1852, p. 34; 1870, p. 



54- 



