SYNOPSIS OF THE NAIADES— SIMPSOX. 871 



t PRISODON ALATUS Sowerby.i 



* Syria alata Sowerby, Conch. Icon., XVII, 1869, pi. v, lig. 13, — P.etel, Conch. 



Sam., Ill, 1890, p. 189. 



Guiana. 



PRISODON CASTELNAUDI Hupe. 



* Hyria castelnaadi Hupe, Moll. Nouv., Ill, 1857, p. 81, pi. xv.r, fig. 1. — * Sow- 



erby, Conch. Icon., XVII, 1869, pi. iv, fig. 8. — * P^tel, Conch. Sam., Ill, 

 1890, p. 189.^ 



Brazil. 



t PRISODON OBLIQUUS Schumacher. 



* Prisodon obliquus Schumacher, Ess. Noua^. Syst., 1817, p. 139, pi. xl, fig. 2.^ 



* Hyria ohliqiia PiETEL, Conch. Sam., Ill, 1890, p. 189. 



*Hyria avicidcms 'LxMARCK, An. sans Vert., VI, 1819, p. 82. — * Crouch, 111. Int. 

 Lam., 1827, p. 16, pi. ix, figs. 5 a, &.— *Stark, Nat. Hist., II, 1828, p. 89.— 

 *Wyatt, Man. Conch., 1838, p. 67, pi. v, fig. 4. — * Delessert, Rec. Co(i. Lam., 

 1841,pl.xii, fig. 9.— "Hanley, Test. Moll., 1842, p. 214; *Biv. Shells, 1843, p.' 

 214, pi. XXIV, fig. 11. — * Catlow and Reeve, Conch. Nom., 1845, p. 65. — 

 ■ Troschel, Arch, fiir Nat., XIII, Pt. 1, 1847, p. 271, pi. vi, fig. 3.—* Chexu, 

 Man., 1859, II, p. 149, fig. 734.— - Sowerby, Conch. Icon., XVII, 1869, pi. in, 

 figs. 6 a, i. 



" Umo fflDicwZam Desha YES, Enc. M^th., II, 1830, p. 583; ^Traite Elem. Conch., 

 1839, p. 18, pi. XXIX, figs. 10, 11. 



* Hyria avicularia Guerix, Icon. Regue An., 1844, II, pi. xxviii, fig. 8. 



" Unio caudatus Wagner, Test. Fluv. Bras., 1827, p. 35, pi. xxvii, figs. 1, 2. . 

 " Diplodon furcatum Spix, Test. Flnv. Bras., 1827, p. 35, pi. xxvii, figs. 1, 2. 



* Hyria elongata Swainson, Ex. Conch., 1841, p. 29, pi. xxiv. 



'^ Triqueira elongata H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 508. 



Amazon draiiiage; southward through Brazil. 



PRISODON RECTUS Sowerby.^ 



'* Hyria recta Sowerby, Conch. Icon., XVII, 1868, pi. v, fig. 10. — * PiETEL, Conch. 

 Sam., Ill, 1890, p. 189. 



South America; locality unknown. 



t PRISODON BROWNIANUS Lea. 



* Unio hrotv7iianus Lea, Tr. Am. Phil. Soc, 1838, p. 108, pi. xxiv, fig. 116; * Obs., II, 



1838, p. 108, pi. XXIV, fig. 116.— * Troschel, Arch, fiir Nat., V, 1839, Pt. 2, 

 p. 237. 



* Margarita ( Unio) iroivnianiis Lea, Syn., 1838, p. 13. 



"Hyria hrowniana Hanley, Test. Moll., 1842, p. 215; * Biv. Shells, 1843, p. 215.— 

 * Catlow and Reeve, Conch. Nom., 1845, p. 65. — * Sowerby, Conch. Icon., 

 XVII, 1869, pi. V, fig. 12.—* PiETEL, Conch. Sam., Ill, 1890, p. 189. 



' This form has the posterior wing greatly produced and curved upward. I doubt 

 whether it is more than a form of syrmatoplwra. 



^This is probably a variety of ohliqii us Schumacher. 



^Only a part of the interior is figured, but from its form I think there need be no 

 doubt as to what the author meant. 



^This may be only a peculiar ohliqima. The dorsal line curves up in the center. 



