srxorsis of the y.uADEs—sfirpsox. 545 



' i'nio (Ligumia) recta Swainson, Treat, on Mai., 1840, pp. 267, 274, fig. lv. 



Unio rectus SnoRT emd Eaton, Transylvania Jl., 1831, p. 77. — * Conrad, New F. 

 W. Shells, 1834, p. 71.—* Say, Am. Conch., VI, 1834.—* Feeussac, Guer. Mag., 

 1835, p. 27.— *Conrad, Monog., Ill, 1836, p. 33, pi. xv.— *Hanley, Test. Moll., 

 1842, p. 204.—* C. B. Adams, Thompson's Hist, of Vt., 1842, p. 167; *F.W. 

 and L. Sh. of Vermont, 1842, p. 17.—* Hanley, Biv. Shells, 1843, p. 204.— 

 * De Kay% Zool. of N. Y., Pt. 5, 1843, p. 195.—* Potiez and Michaud, Gall. 

 Moll., 1844, II, p. 149, pi. LVii, figs. 3, 4. — *" Catloav and Eeeve, Conch. Nom., 

 1845, p. 63. — *IvrsTER, Conch. Cab. Unio, 1852, p. 35, pi. vi, fig. 1; vii, fig. 

 l._* Conrad, Pr. Ac. N. Sci.,Phila., VI, 1853, p. 256.— * H. and A. Adams, 

 Gen. Eec. Moll., II, 1857, p. 491.— *Chenu, Man., 1859,11, p. 139, fig. 675.— 

 Reeve, Conch. Icon., XVI, 186.5, pi. xix, fig. 86. — * Calkins, Pr. Ottawa Ac, 

 1874, p. 44.— * Latchford, Tr. Ottawa F. N. Club, 1882, p. 50.— * B. H. 

 Wright, Check List, 1888.—* P^etel, Conch. Sam., Ill, 1890, p. 165.—* Call, 

 Tr. Ac. Sci., St. Louis, VII, 1895, p. 43, pi. vii. 



* Margarita ( Unio) rectus Lea, Syn., 1836, p. 34; 1838, p. 23. 

 *Margaron ( JJnio) rectus Lea, Syn., 18.52, p. 35; 1870, p. 57. 

 ""Lampsilis rectus Smith, Bull. U. S. Fish Com., 1899, p. 290, pi. lxxviii. 



t* Unio latissima Rafinesque, Ann. Gen. Sci. Phys. Brux., Pt. 13, V, 1820, p. 297, 

 pi. Lxxx, figs. 14, 15. 



* '^Unio prcelongus Barnes,^ Am. .Jl. of Sci., VI, 1823, p. 261, pi. xiii, fig. li. — 

 *Hildreth, Am. Jl. of Sci., XIV, 1828, p. 286, fig. 18. 



""Mya prcelonga Eaton, Zool. Text-Book, 1826, p. 220.— Wood, Ind. Test (Han- 

 ley), 1856, p. 200, pi. I, Supp., fig. 11. 



* Eurynea lyroilonga Stimpson, Shells of N. Eng., 1851, p. 13. 



t* Unio sageri Conrad, Monog., VI, 1836, p. 53, pi. xxix, fig. 1. 



* 1 Unio' arquattis" Conrad, .11. Ac. Nat. Sci. Phila., 1854, p. 297, pi. xxvi, fig. 8. — 



B. H. Wright, Check List, 1888. 



pjutire Mississippi drainage; Alabama River drainage; Red River of 

 the North ; St. Lawrence system. DeCamp's Unio anodontoides, reported 

 from Michigan, is a tawny colored variety of this species according to 

 Walker. 



(Group of Lampsilis nasutus.) 



Shell elongated, thin, compressed, with a distinct posterior ridge, and 

 drawn out to a long, pointed beak behind; epidermis rather dull, olive 

 green, and feebly rayed; beaks low, sculptured with fine, close-set 

 ridges, which are slightly looped in front and are parallel with the axis 

 of the shell behind; hinge teeth delicate and compressed; nacre bluish; 

 female shell not greatly produced in the post-basal region. Animal 

 with the marsupium often occupying the greater x)art of the length 

 of the outer gills posteriorly; inner gills free or united to the, abdomi- 

 nal sac. 



t LAMPSILIS NASUTUS Say. 



Unio nasutus Say, Nich. Encyc, 1st ed., 1816, pi. iv, fig. 1. — *Swainson, Zool. 111., 

 Istser., 1,1821, pi. Lvii.— *Conrad, NewF. W. Shells, 1834, p. 70.— *Ferussac, 

 Guerin Mag., 1835, p. 26.— * Conrad, Monog., IV, 1836, p. 38, pi. xviii, fig. 1, 



'Barnes only gives an outline of his shell, which appears to me more like his U. 

 gihiosus than rectus. However in deference to the opinions of Hildreth, Lea, and 

 others, I place it in the synonymy of L. rectus. Hildreth's description answers fairly 

 well to rectus, and it was submitted to Barnes for his inspection. 



2 Lea believes this to be a distorted rectus. I am not quite certain of it. 

 Proc. N. M. vol. xxii 35 



