NO. 1205. SYNOPSIS OF THE NAIADES— SIAfPSON. 571 



1853, p. 258.— *Chenu, 111. Concli., 1858, pi. xxi, figs. 5, 5a, 5&.— 'H. and A. 

 Adams, Gen. Rec. Moll., II, 1857, p. 495.—* ? Kuster, Conch. Cab. Uuio., 1862, 

 p. 275, pi. xciii, tig. 1. — *fSoWERi5Y, Conch. Icon., XYI, 1867, pi. lvii, fig. 

 291.— *B. H.Wright, Check List, 1888.— 'PvETel, Conch. Sam., Ill, 1890, 

 p. 169.—* Fischer and Crosse, Miss. Sci. Pt. 7, II, 1894, p. 586.i 



* Margarita ( Unio) tampecoensis Lea, Syn., 1836, p. 22; 1838, p. 18. 



* Margaron ( Unlo) tampecoensis Lea, Syn., 1852, p. 26; 1870, p. 41. 



* Unio heermannii Lea, Pr. Ac. N. Sci. Phila,, XIII, 1861, p. 392; Ml. Ac. N. gci. 



Phila.,V, 1862, p. 194, pi. xxvi, fig. 263; * Obs. IX, 1863, p. 16, pi. xxvi, fig. 

 263.— *?SowERBY, Conch. Icon., XVI, 1868, pi. lxxxiii, fig. 441.— "B. H. 

 Wright, Check List, 1888.— "P.etel, Conch. Sam., Ill, 1890, p. 154. 



* Margaron ( Unio) heermannii Lea, Syn., 1870, p. 28.'- 



Northeastern Mexico ; southeastern Texas ; Honduras. 



fLAMPSILIS TECOMATENSIS Lea. 



^ Unio teoomatensis Lea, Pr. Am. Phil. Soc, II, 1841, p. 30; "Tr. Am. Phil. Soc.,VIII, 

 1842, p. 234, pi. XXI, fig. 48; * Obs., Ill, 1842, p. 72, pi. xxi, fig. 48.— Coxrad, Pr. 

 Ac. N. Sci. Phila., VI, 1853, p. 258.— 'H, and A. Adams, Gen. Rec. Moll., II, 

 1857, p. 495.— *Chenu, 111. Conch., 1858, pi. xxxi, figs. 6, 6a, 6&.— ■ B. H. 

 Wright, Check List, 1888.—* Fischer and Crosse, Miss. Sci., Pt. 7, II, 1894, 

 p. 589, pi. Lxv, fig. 6; lxvi, figs. 4, 4a. 



" Margaron ( Unio) tecomatensis Lea, Syn., 1852, p. 27; 1870, p. 50. 



Tecomata Kiver, Mexico. 



LAMPSILIS LIVIDUS Simpson.^ 



""Unio tesfudinens Rkeve, Conch. Icon., XVI, 1865, pi. xxii, fig. 101. 

 " Unio expHcatus Fischer and Crosse, Miss. Sci., Pt. 7, II, 1894, p. 594. 



Rio Usumasinto, Portugal, according to Reeve, who no doubt intended 

 this for Rio TJsumasiiita, Mexico, and Guatemala. 



t LAMPSILIS EXPLICATUS Morelet. 



* Unio explicatns Morelet, Test. Noviss, Pt. 1, 1849, p. 28.^ — Fischer and Crosse, 



Miss. Sci., Pt. 7, II, 1894, p. 594, pi. lxi, fig. 1. 



* Margaron ( Unio) semigranosus Lea, Syn., 1870, p. 34. 



Gentral America. 



^Fischer and Crosse (see above citation) doubt whether Sowerby's figures in Conch. 

 Icon, and Kuster's in Conch. Cab. are tampecoensis. Though not very accurate figures, 

 I can not refer them equally well to any other species. 



^Lea has two siiecimens of heermannii in his collection ; the type, which is a young, 

 slightly injured shell, and a very young one. I am certain it is only tampecoensis. 



■Reeve described and figured this form in the Conchologia, supposing it to be the 

 iestudineiis of Morelet, whicli is a very different thing. Fischer and Crosse in Mission 

 Scientifique, believing it to be equal to Morelet's explicatns, placed it in the syn- 

 onymy of that species. I have never seen an absolutely authentic specimen oi expli- 

 catiis, but if Fischer and Crosse have accurately figured and described it, I am sure 

 it is flifterent from Reeve's species, the latter being evidently more inflated, smoother, 

 differently shaped, and having a great deal higher beaks. This being the case, it 

 becomes necessary to give Reeve's shell a new name. Fischer and Crosse credit the 

 species to Sowerby, but the Plate xxii, in the Conchologia, is credited to Reeve. 



^A single valve of what is probably this species was received by the United 

 States National Museum from Dr. H. von Ihering, under the name of Unio expUcatus 

 Morelet. 



