NO. 1205. SYNOPSIS OF THE NAIADES SIMPSON. 871 



t PRISODON ALATUS Sowerby. 1 . 



* Hyria alata SOWERBY, Conch. Icon., XVII, 1869, pi. v, fig. 13. PYETEL, Conch. 



Sam., Ill, 1890, p. 189. 



Guiana. 



PRISODON CASTELNAUDI Hupe. 



* Hyria castelnaudi HUPE, Moll. Nouv., Ill, 1857, p. 81, pi. xvr, fig. 1. * SOW- 



ERBY, Conch. Icon., XVII, 1869, pi. iv, fig. 8.* PA:TEL, Conch. Sam., Ill, 

 1890, p. 189.'^ 



Brazil. 



t PRISODON OBLIQUUS Schumacher. 



* Prisodon obliquus SCHUMACHER, Ess. Nouv. Syst., 1817, p. 139, pi. XL, fig. 2. 3 



* Hyria obliqua P^TEL, Conch. Sam., Ill, 1890, p. 189. 



* Hyria avicularis LAMARCK, An. sans Vert., VI, 1819, p. 82. * CROUCH, 111. Int. 



Lam., 1827, p. 16, pi. ix, figs. 5 a, b.* STARK, Nat. Hist., II, 1828, p. 89. 



* WYATT, Man. Conch., 1838, p. 67, pi. v, fig. 4. * DELESSERT, Rec. Coq. Lam., 

 1841, pi. xn, fig. 9.' HANLEY, Test. Moll., 1842, p. 214 ; * Biv. Shells, 1843, p. 

 214, pi. xxiv, fig. 11. * CATLOW and REEVE, Conch. Norn., 1845, p. 65. 



* TROSCHEL, Arch, fur Nat., XIII, Pt. 1, 1847, p. 271, pi. vi, tig. 3.* CHENU, 

 Man., 1859, II, p. 149, fig. 734. * SOWERBY, Conch. Icon., XVII, 1869, pi. m, 

 figs. 6 a, b. 



* Unio avicularis DESHAYES, Enc. M6th., II, 1830, p. 583; 'Traite Elem. Conch., 



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



* Hyria acicularia GUERIX, Icon. Regne An., 1844, II, pi. xxvin, fig. 8. 



* Unio caudatus WAGNEU, Test. Fluv. Bras., 1827, p. 35, pi. xxvn, figs. 1, 2. 



* Diplodon furcatum SPIX, Test. Fluv. Bras., 1827, p. 35, pi. xxvu, figs. 1, 2. 



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



* Triquetra elongata H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 508. 



Amazon drainage; southward through Brazil. 



PRISODON RECTUS Sowerby. 4 



* Hyria recta SOWERBY, Conch. Icon., XVII, 1868, pi. v, fig. 10. * P^ETEL, Conch. 



Sam., Ill, 1890, p. 189. 



South America; locality unknown. 



t PRISODON BROWNIANUS Lea. 



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



1838, p. 108, pi. xxiv, fig. 116. * TROSCHEL, Arch. fiirNat., V, 1839, Pt. 2, 

 p. 237. 



* Margarita ( Unio) brownianus LEA, Syn., 1838, p. 13. 



* Hyria browniana HANLEY, Test. Moll., 1842, p. 215; * Biv. Shells, 1843, p. 215. 



* CATLOW and REEVE, Conch. Norn., 1845, p. 65. * SOWERBY, Conch. Icon., 

 XVII, 1869, pi. v, fig. 12.* PJSTEL, Couch. Sam., Ill, 1890, p. 189. 



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

 whether it is more than a form of syrmatophora. 



2 This is probably a variety of obliquus Schumacher. 



3 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. 



4 This may be only a peculiar obliquy*. The dorsal line curves up in the center. 



