792 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



Conch., 1858, pi. xv, figs. 1, la, 15.—* Kuster, Conch. Cab., 1861, p. 190, pi. lx, 

 fig. 3.— *B. H. Wright, Check List, 1888. 



* Margarita ( Unio) suirotundus Lea, Syn., 1836, p. 34; 1838, p. 23. 

 *Margaron ( Unio) subrotundus Lea, Syn., 1852, p. 35 ; 1870, p. 56. 



• * 1 Unio Irevialis Crouch, 111. Int. to Lamarck, 1827, p. 16, pi. ix, fig. 3.'— '' f Cat- 

 low and Reeve, Conch. Norn., 1845, p. 56. 



* Unio personatus Conrad, New F. W. Shells, 1834, p. 71. 



" Uviopolitus Say, Am. Conch., VI, 1834.^—* Ferussac, Guer. Mag., 1835, p. 28.— 

 * Conrad, Monog., VIII, 1837, p. 67, pi. xxxvii, fig. 2.—* Kuster, Conch. 

 Cab. Unio, 1852, p. 62, pi. xiv, fig. 4.—* Conrad, Pr. Ac. N. Sci. Phila., 

 VI, 1853, p. 255.— * SOWERBT, Conch. Icon., XVI, 1866, pi. xxxii, p. 168.— 

 ^PiETEL, Conch. Sam., Ill, 1890, p. 164.3 



Ohio, Cumbeiiaud, and Tennessee river systems. Eeported from 

 Michigan and the Grand River, Ontario, but it is probable that the 

 material from these localities is not subrotundus. 



tQUADRULA PILARIS Lea. 



* Unio pilaris Lea, Pr. Am. Phil. Soc, 1, 1840, p. 285; Tr. Am. Phil. Soc, VIII, 1842, 



p. 209, pi. XIV, fig. 24 ; Obs., Ill, 1842, p. 47, pi. xiv, fig. 24.—* Conrad, Pr. Ac. 

 N. Sci. Phila., VI, 1853, p. 255.— *H. and A. Adams, Gen. Rec. Moll., II, 

 1857, p. 492.— *Chenu, 111. Conch., 1858, pi. xxix, figs. 3, 3a, 3&.—* Kus- 

 ter, Conch Cab., 1861, p. 255, pi. lxxxvi, fig. 3.—* Reeve, Conch. Icon., 

 XVI, 1865, pi. XXVII, fig. 138.— *B. H. Wright, Check List, 1888.— *P^tel, 

 Conch. Sam., Ill, 1890, p. 163. 



* Margaron ( Unio) pilaris Lea, Syn., 1852, p'. 35 ; 1870, p. 56. 



]*Unio lesueiirianus Lea, Pr. Am. Phil. Soc. I, 1840, p. 286; *Tr. Am. Phil. Soc, 

 VIII, 1842, p. 195, pi. VIII, fig. 6; *Obs., Ill, 1842, p. 33, pi. viii, fig. 6.— 

 *CoNRAD, Pr. Ac. N. Sci. Phila., VI, 1853, p. 251.— *H. and A. Adams, Gen. 

 Rec. Moll., 11, 1857, p. 492.— * Chenu, 111. Conch., 1858, pL xxx, figs. 4, 4a, 

 4&.— ^Kuster, Conch. Cab. Unio, 1861, p. 215, pi. lxxii, fig. 2.— *B. H. 

 Wright, Check List, 1888.— *P^tel, Conch. Sam., Ill, 1890, p. 157. 



* Margaron ( Unio) lesueiirianus Lea, Syn., 1852, p. 35 ; 1870, p. 56. 



Tennessee and Cumberland river sytemsj Green River, Kentucky; 

 reported from the Ohio River. 



tQUADRULA CUNEUS Conrad.^ 



* Unio cuneus Conrad, Monog., XII, 1840, p. 105 ; pi. lviii, fig. 1.—* B. H. Wright, 



Check List, 1888. 



Arkansas; Louisiana; Sabine River, Texas. 



1 The figure looks something like subrotunda, or it may possibly be ehenw^. I can 

 not make out Lamarck's irevialis (An. sans Vert., VI, 1819, p. 75), which he says came 

 from the Isle de France. Sganzin was told by the people of the island that no Unio 

 was found there (Mem. Hist. Nat. Strasb., Ill, 1846, p. 8). 



2 Merely listed by Say, but neither Lea nor I have been able to find that it was ever 

 described by him. 



^Kirtland states that an oblique sulcatiou below the superior posterior angle dis- 

 tinguishes the female of this species, as it does the retusiis, from the male. I have 

 not noticed it. 



' Mr. Conrad states in the Monography that his shells came from the Little Red 

 River, Arkansas. Our shells in the U. S. National Museum collection are from the 

 same stream, but are not quite so solid, nor are they just the shape of the figure, yet 

 I have no doubt that they are cuneus. 



