518 PROCEEDINGS OF THE NATIONAL MUSEUM. 



* Unio interrupt us CONRAD, New F. \V. Shells, 1834, p. 69.* SAY. Am. Conch., VI, 



1834. *CONRAD, Monog.,X, 1838, p. 88, pi. XLVIII; *Pr. Ac. N. Sci., Phila., 

 VI, 1853, p. 250. *KrsTKK, Conch. Call. Uuio, 1861, p. 182, pi. i.vn, fig. 3; 

 pi. LX, iig. 2.* REEVE, Conch. Icon., XVI, 1864, pi. xiv. lig. 56. 

 ^Truncilla interrupta AGASSI/, Arch, fiir Naturg., I. 1852, p. 44. 



Tennessee drainage. 



+ TRUNCILLA PENITA Conrad. 



* Unio penitiis CONRAD, New F.W. Shells, 1834, pp. 33, 70, pi. v, fig. 1. * FEUUSSAC, 



(Jiirr. Mag., 1835, p. 29. *M6LLER, Syn. Nov. Gen., 1836, p. 203. HANI.EY, 

 Test. Moll., 1842, p. 183; * Biv. Shells, 1843, p. 183. *CATLOW and REEVE, 

 Conch. Nom., 1845, p. 62. * CHENU, Bib. Conch., 1st ser., Ill, 1845, p. 18, pi. in, 

 fig. 9.* CONRAD, Pr. Ac. N. Sci., Phila., VI, 1853, p. 254.* H. and A. ADAMS, 

 Geu.Eec. Moll. , II, 1857, p. 495. * REEVE, Conch. Icon., XVI, 1864, pi. xiv, 

 fig. 55. *P.ETEL, Conch. Sam., Ill, 1890, p. 162. 



"Margarita ( Unio) penitiis LEA, Syn., 1836, p. 19; 1838, p. 16. 



*Mar(jaron ( Unio) penitiis LEA, Syn., 1852, p. 24; 1870, p. 36. 



* Unio compactiis'LE\, Proc. Ac. N. Sci. Phila., Ill, 1859, p. 154 ; * Jl. Ac. N. Sci. Phila., 



IV, 1859, p.218, pi. xxvin, fig. 98 ; * Obs. VII, 1859, p. 36, pi. xxvin, fig. 98. 

 *Maryaron ( Unio) compact us LEA, Syn., 1870, p. 36. 



Alabama aud Tombigbee river drainage. 



tTRUNCILLA MODICELLA Lea. 



*Unio modicellus LEA, Pr. Ac. Phila., Ill, 1859, p. 171; *J1. Ac. N. Sci. Phila., IV, 

 1860, p. 347, pi. LVII, fig. 172 ; *Obs., VIII, 1860, p. 29, pi. LVII, fig. 172.* B. H. 

 WRIGHT, Check List, 1888. 



*Margaron (Unio) modicellus 1 LEA, Syn., 1870, p. 41. 



Conuasaugua and Chattanooga rivers, northwest Georgia. 



The following species a are unfigured and indeterminate: 



Truncilla ( Unio) perplexus Rafinesque. 



TrunciHu granulates Rafinesque. 



Unio (Truncilla) metaplata Rafinesque. 



tTRUNCILLA LENIOR Lea. 



'' rnio lenis LEA, Pr. Am. Phil. Soc., 1, 1840, p. 286. :i 



*Unio lenior LEA., Tr. Am. Phil. Soc., VIII, 1843, p. 204, pi. xn, fig. 18; *Obs., Ill, 



1842, p. 42, pi. xn, fig. 18. *CONRAD, Pr. Acad. N. Sci. Phila., VI, 1853, p.1'51. 



*CHENU, 111. Conch., 1858, pi. xxvn, figs. 4, 4a, 4&. *H. and A. ADAMS, Gen. 



Rec. Moll. ,11, 1857, p. 492. *REEVE, Conch. Icon., XVI, 1864, pi. xvn, fig. 



75. *P.ETEL, Conch. Sam., Ill, 1890, p. 157. 

 *Margaron\Unio) lenior LEA, Syu., 1852, p. 39; 1870, p. 62. 



Stone lliver, Tennessee; near Woodville, Alabama. 



'Four specimens of this species are in the U. S. National Museum collection, from 

 the Connasauga River, Georgia, three of which are males, with a form something 

 like that of T. penita; the fourth is a young female, which distinctly shows a 

 radiately ridged post-basal swelling. 



Q These are in continuation of Monographer, 1831, p. 4. 



3 Lea changed his name lenix to lenior, probably because Conrad had previously 

 used the former for a species of Unio, which is no doubt a young rentricosus. 



