No.1205. SYNOPSIS or rui: \.u. IDES SIMPSON. 571 



1853, p. 25S. *CHENU, 111. Conch., 1858, pi. xxi, figs. 5, 5a, 5Z. *H. and A. 

 ADAMS, Gen. Kec. Moll., II, 1857, p. 495.' ? KUSTER, Conch. Cab. Unio., 1862, 

 p. 275, pi. xciu. tig. 1. *?SOWERBY, Conch. Icon., XVI, 1867, pi. LVII, fig. 

 291. *B. H.WRKJHT, Check List, 1888. * P.ETKL, Conch. Sam., 111,1890, 

 p. 169.* FISCHKK and CROSSK, Miss. Sci. Pt. 7, II, 1894, p. 586.' 



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



* Margaron ( Unio) tampecocnsis LEA, Syn., 1852, p. 26; 1870, p. 41. 



* Unio Iteermannii LKA, Pr. Ac. N. Sci. Phila., XIII, 1861, p. 392; *J1. Ac. X. Sci. 



Phila., V, 1862, p. 194, pi. xxvi, tig. 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.KTEL, Conch. Sam., Ill, 1890, p. 154. 

 " Margaron ( Unio) heermannii LEA, Syn., 1870, p. 28. c 



Northeastern Mexico; southeastern Texas; Honduras. 



fLAMPSILIS TECOMATENSIS Lea. 



* Unio tecomateiisis 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. CONRAD, 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, 6b. * 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) tecomatejisis LEA, Syn., 1852, p. 27; 1870, p. 50. 



Tecomata River, Mexico. 



LAMPSILIS LIVIDUS Simpson. 1 



"Unio testudineus REEVE, Conch. Icon., XVI, 1865, pi. xxn, fig. 101. 



* Unio explicatus FISCHER and CROSSE, Miss. Sci., Pt. 7, II, 1894, p. 594. 



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

 this for Rio Usumasinta, Mexico, and Guatemala. 



t LAMPSILIS EXPLICATUS Morelet. 



* Unio explicatus MORELET, Test. Noviss, Pt. 1, 1849, p. 28. 4 FISCHER and CROSSE, 



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



* Margaron ( Unio) semiyranosus LEA, Syn., 1870, p. 34. 



Central America. 



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

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

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



2 Lea has two specimens of heermanmi in his collection ; the type, which is a young, 

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



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

 lestudinens of Morelet, which is a very different thing. Fischer and Crosse in Mission 

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

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

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

 it is different 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 ;md Crosse credit the 

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



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

 States National Mnseum from Dr. H. von Ihering, under the name of Unio explicatus 

 Morelet. 



