Call — The Unionidoe of Arkansas. 21 



iaua ; it occurs abundantly in the St. Francis river, at Witts- 

 burg, and in the Saline river at Benton. It is a synonym of 

 Unio luteolus Lamarck, to which the reader is referred. 



Unio lachrymosus Lea. 



Transactions Am. Philos. Soc, 2nd series, 1827, p. 

 272, PI. VI, Fig. 8. Described from Ohio. Also Reeve, 

 in Conchologia Iconica, 1864, Unio PI. IX, Fig. 33. 



Unio asperrimus Lea. Trans. Am. Philos. Soc, 2d 

 series. Vol. IV, p. 71, PI. V, Fig. 3. 1830-1. 



Unio quadrulus Rafinesque, so Say, in Am. Conch., PI. 

 53, 1834. 



Unio quadrafus, Rafinesque, so Reeve, in Conchologia 

 Iconica, Unio Plate VI, Fig. 24, 1864. 



Unio lunulatus^ Pratt. Proc. Davenport Acad. Sci., 

 Vol. I, PI. XXXI, Fig. 1, (1870?). 

 Obtained by us in the St. Francis river, at Wittsburg, and 

 in the Saline river, at Benton. Unio lachrymosus was 

 described from a small and immature specimen ; Unio asper- 

 rimus from an old and well-worn shell. Yet the resemblances 

 are so close that one might easily have recognized their iden- 

 tity. From the Little Arkansas river, Kansas, come the 

 largest and finest specimens of this species that we have ever 

 seen. In geographic range the form extends from western 

 New York to Kansas and Minnesota, and south to Texas and 

 Alabama. 



Unio i^^vissimus Lea. 



Trans. Am. Philos. Soc, Vol. Ill, PI. XIII, pp. 444-445. 

 Specimens of this form were taken by Dr. J. C. Branner, 

 in the Little Red river, at Fulton. The shell is somewhat 

 more globose than the same form reported from other local- 

 ities ; the specimens have a slight tendency to vary toward Unio 

 hermannii Lea, described originally from Texas. The types 

 of Lea's Unio Icevissimus came from the Ohio, in which 

 stream it is by no means uncommon. The range of this form 

 is from Western or middle Ohio to Kansas and Nebraska; 

 southward it ranges to Trinity river, Texas. It is a member 

 of the bi-alate group, the leading term of which is Unio alatus 

 Say. 



