564 PROCEEDINGS OF THE NATIONAL MUSEUM. 



\*Unio &eaZei Lea, Pr. Ac. N. Sci. Phila., VI, 1862. p. 169; ' Jl. Ac.N. Sci. Phila., V, 

 1862, p. 204, pi.' XXX, fig. 273; *Obs., IX, 1863, p. 26, pi. xxx, fig. 273.— *B. H. 

 Wright, Check List, 1888. 



*Mavgaron ( Unio) healei Lea, Syu. 1870, p. 49. 



t LAMPSILIS TEXASENSIS var. COMPRESSUS Simpson.' 



Texas, north to Kansas; Missouri; southern Illinois and Indiana; 

 south through Tennessee, Alabama, Mississippi, and Louisiana; the 

 variety in southwest Texas. 



tLAMPSILIS MEARNSI Simpson. 

 "Lampsilia mearnsi Simpson, Pr. Ac. N. Sci. Phila., 1900, p. 75, pi. i. tig. 4. 

 Vicinity of Fort Clarke, Kinney County, Texas. 



t LAMPSILIS PARVUS Barnes. 



"^ Unio parvus Baknes, Am. Jl. Sci., VI, 1823, pi. xiii, fig. 18 (outline).- — Short and 

 Eaton, Transylvania Journal, 1831, p. 78. — *Conrad, New F. W. Shells, 1834, 

 p. 70.— *Say, Am. Conch., VI, 1834.— Ferussac, Guer. Mag., 1835, p. 26.— 

 *Hanley, Test. Moll., 1842, p. 196.— " Philippi, Abbild, I, 184.5, p. 19, pi. i, 

 fig. 4. — *Catlow and Reeve, Conch. Nom., 1845, p. 62. — *Kustp:r, Conch. Cab. 

 Unio, 1852, p. 33, pi. v, fig. 5.—* Conrad, Pr. Ac. N. Sci. Phila., VI, 1853, p. 

 25.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 494.— *B. H. Wright, 

 Check List, 1888.— *P^tel, Conch. Sam., Ill, 1890, p. 162. 



"" Margarita ( Unio) parvus Lea, Syn., 1836, p. 28; 1838, p. 21. 



""Margaron ( Unio) parvus Lea, Syn., 1852, p. 31; 1870, p. 49. 



""Lampsilis parvus Baker, Moll. Chicago, Pt. 1, 1898, p. 109, pi. xiii, fig. 3. 



*Myaparra Eaton, Zool. Text- Book, 1826, p. 222. 



Mississippi River drainage generally; southwest to central Texas; 

 western Kew York ; southern Canada; and Michigan doubtfully. 



tLAMPSILIS HALEIANUS Lea.^ 



* Unio haleianus Lea, Pr. Am. Phil. Soc, II, 1842, p. 224 ; * Tr. Am. Phil. Soc, VIII, 

 1842, p. 247, pi. xxvii, fig. 63 ; ^ Obs., Ill, 1842, p. 85, pi. xxvii, fig. 63.— Con- 

 rad, Pr. Ac. Nat. Sci. Phila,, VI, 1853, p. 250.— ''H. and A. Adams, Gen., Rec. 

 Moll., II, 1857, p. 494.— ^Chenu, 111. Conch., 1858, pi. xxvi, figs. 6, 6a, 6&.— 

 * ? Reeve, Conch. Icon., XVI, 1865, pi. xxiv, fig. 116.—* B. H. Wright, Check 

 List, 1888.—* P^TEL, Conch. Sam., Ill, 1890, p. 154. 



*Margaron ( Unio) haleianus Lea, Syn., 1852, p. 31; 1870, p. 49. 



Alexandria, Louisiana; eastern Texas. 



1 A remarkably compressed elevated form from southwest Texas may bear this name. 



"Barnes's outline shows a small shell, evenly rounded posteriorly. I believe that 

 this character of being rounded behind is constant, and is the only one by which if 

 always differs from its near ally, L. texasensis, which is more sharp behind and usually 

 obliquely truncate at the post-base. The two species have been continually con- 

 founded, and even Dr. Lea has placed in his collection under the name parvus a 

 number of specimens which I am sure are his texasensis. The former is generally the 

 smaller of the two, though not always, as in northern Illinois it sometimes reaches 

 a length of 2 inches. L. texasensis undoubtedly ranges north into northern Missouri, 

 southern Illinois and Indiana, and the true parvus is occasionally found well down 

 into Texas. 



^This is often confounded with L. texasensis. It is a larger, thinner-shelled form, 

 and is not so decidedly truncate at the post-basal region. 



