568 PEOCEEDINGS OF THE NATIONAL MUSEUM. vor.xxii. 



fLAMPSILIS ALATUS var. POULSONI Conrad. 



* Uvio iwuUoni Conrad, New F. W. Shells, 1834, p. 25, pi. i, p. 71. — *M5ller, 



Syn. Nov. Gen., 1836, p. 200.—* Chenu, Bib. Couch., 1st ser.. Ill, 1845, p. 15, 

 pi. I, fig. 7.— ^B. H. Wright, Check List, 1888.— 'P^.tel, Conch. Sam., Ill, 

 1890, p. 164. 

 '" Sympliynota poulsoni Ferussac, Guer. Mag., 1835, p. 25. 



* Unio inftatus Conrad, Monog., VII, 1836, p. 57, pi. xxxii.' 



Entire Mississippi drainage as far south as Arkansas; St. Lawrence 

 drainage; Eed River of tlie North; the variety in the Alabama and 

 Tombigbee systems. 



fLAMPSILIS COLORADOENSIS Lea. 



* Unio coloradoensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 103; "Jl. Ac. N. Sci. 



Phila.,111, 1858, p. 314, pL xxxi, fig. 29; *Obs., VI, 1857, p. 34, pi. xxxi, fig. 

 29.—* B. H. Wright, Check List, 1888. 

 *Margaron (Unio) coloradoensis Lea, Syn., 1870, p. 41. 



Eastern Texas. 



fLAMPSILIS ROVIROSAI Pilsbry. 



* Unio (Lampsilis) rovirosai Pilsbry, Nautilus, XIII, 1900, p. 140. 

 Laguna de Atasta, near San Juan Bautista, Mexico. 



fLAMPSILIS PURPURATUS Lamarck. 



*Unio pur purata 1j AM ARCK, An. sans Vert., VI, 1819, p. 71. — * Stark, Nat. Hist., 

 II, 1828, p. 90.—* Deshayes, An. sans Vert., 2d ed., VI, 1835, p. 533 ; 3(1 ed., II, 

 1839, p. 667. 



* Unio purpuratus Lea, Obs., I, 1834, p. 199.— * Ferussac, Guer. Mag., 1835, 'p. 26. — 



* Hanley, Test. Moll., 1842, p. 208; * Biv. Shells, 1843, p. 208, pi. xxii, fig. 5.— 

 *Catlow and Reeve, Conch. Nom., 1845, p. 63. — * Conrad, Pr. Ac. N. Sci. 

 Phila., VI, 1853, p. 2.55.— ■ Kuster, Conch. Cab. Unio, 1861, p. 185, pi. Lix, 

 fig. 1. — * Reeve, Conch. Icon., XVI, 1865, pi. xxiv, fig. 115. — * B. H. Wright, 

 Check List, 1888.—* P^tel, Conch. Sam., Ill, 1890, p. 164.—* Pilsbry, Nau- 

 tilus, V, 1891, p. 76.—* Call, Tr. Ac. Sci. St. Louis, VII, No. 1, 1895, p. 38, pi. v. 



* Margarita (Unio) purpuratus Lea, 1836, p. 39; 1838, p. 25. 



* Margaron ( Unio) purpuratus Lea, Syn., 1852, p. 38 ; 1870, p. 61. 



t Unio ater Lea, Tr. Am. Phil. Soc, III, 1830, p. 426, pi. vii, fig. 9; *Obs., I, 1834, 

 p. 40, pi. VII, fig. 9.— *CoNRAD, New F. W. Shells, 1834, p. 67.—* Chenu, 111. 

 Conch., 1858, pi. x, figs, la, Ih. 



Unio aira Deshayes, Enc. Meth., II, 1830, p. 582. 



* Unio lugubris Say, Am. Conch., V, 1832, pi. xliii ; VI, 1834. 



* Unio poulsoni Sowerby, Conch. Icon., XVI, 1866, pi. li, fig. 270. 



* Unio dolosus Lea,2 Pr. Ac. N. Sci. Phila., IV, 1860, p. 307; * Jl. Ac. N. Sci. Phila., 



V, 1862, p. 75, pi. IX, fig. 224 ; * Obs., VIII, 1862, p. 79, pi. ix, fig. 224.— '" Sow- 



' The variety j;o)i/so}w is narrower anteriorly and more drawn at the post-basal 

 point than the type, and this form is common iu the streams that drain into the Gulf 

 east of the Mississippi, but it seems to connect with typical alatus in Tennessee. 



-A miserable, worn, young specimen of what I am quite sure is L. purpuratus. Lea 

 states that the embryos of this are pouch-shaped, while fhosQoi purpuratus are wedge- 

 shaped, but the form of embryos in a given species is often not constant. 



