(Jail — The Uaionidoz of Arkansas. 53 



pp. 99-100, PI. LV, Fig. 1. Described from near New 

 Orleans, Louisiana. A copy of this figure is given here- 

 with, Plate XX, Pigs. 1-3. 



Unio sayii Ward. So Tappan in Am. Jour. Sci. and 

 Arts, 1st series, Vol. XXXV, 1839, p. 268, PI. Ill, Fig. 

 1; Conrad, Monograph Plate LVI, Fig. 2, as Unio say- 

 anus Ward. These figures are produced herewith, on 

 Plate XIX, figures 3-5. Described from Circleville, Ohio. 

 Unio symmetrica* Lea. Trans. Am. Philos. Soc, Vol. 

 X, 1845, p. 73, PI. IV, Fig. 11. From the Red river, 

 Alexandria, Louisiana. 



Unio subcroceus Conrad. Jour. Acad. Nat. Sci.Phila., 

 2d series, Vol. II, p. 297, 1854, PI. XXVI, Fig. 1. 

 Described from a stream in Arkansas, tributary to the 

 Canadian fork of Red river. 



Unio manubrius Gould. Proc. Bost. Soc. Nat. Hist. 

 Vol. V, 1855, p. 229. From Chihuahua, Mexico. 



Unio jamesi anus Lea. Jour. Acad. Nat. Sci. Phila., 2d 

 series, 1858, Vol. IV, p. 52, PL VI, Fig. 35. Described 

 from a single specimen obtained at Jackson, Mississippi, 

 and then in the cabinet of U. P. James, of Cincinnati. 

 The specimen is a pathologic representative of Unio 

 I' Iralasmus Say. 

 This widely distributed species occurs from Ohio, south to 

 central Alabama and through Texas into Mexico. Its most 

 northern and western locality thus far is central Kansas, not far 

 from Wichita. It preserves its specific characters so generally 

 that it is a matter of great surprise that so many synonyms 

 should fall under it. The study of the figures, descriptions, 

 and localities above indicated, will furnish convincing evidence 

 of identity. Of the total number listed, seven came from 

 Louisiana and contiguous territory; of these seven, five are 

 from the same State, and of these five, two are from the same 

 bayou. The pathologic Unio jamesianus is not the first shell 

 or the only one which has been projected into specific distinc- 

 tion; the small Unio liebii Lea and the Unio hippopceus Lea, 

 both from Lake Erie, are further illustrations. 



This species occurs in Arkansas in the White and the Black 

 rivers, and in the Red river, near the Louisiana boundary. 



