NO. 1205. SYNOPSIS OF THE NAIADES— SIMPSON. 785 



very high; beak sculpture very coarse, concentric ridges ; ' disks irregu- 

 larly concentrically striate; epidermis rich, dark chestnut; hinge plate 

 rather narrow; pseudocardinals radial, stumpy; cavity of the beaks 

 only moderately deep. 



'Eo gravid specimens have been seen, but those examined do not seem 

 to differ from others of the genus. 



tQUADRULA CHICKASAWHENSIS Lea. 



*Unio ckickasaivhensis Lea,, Pr. Ac. N. Sci. PMla., V, 1861; p. 39; *°J1. Ac. N. Sci. 



PMla., V, 1862, p. 101, pi. xvi, fig. 250; *Obs., VIII, 1862, p. 105, pi. xvi, 



fig. 25a— *B. H. Wright, Check List, 1888. 

 Margaron (Unio) cMckasaivhensis Lea, Syn., 1870, p. 55. 



Mississippi and Louisiana. 



tQUADRULA SUCCISSA Lea. 



* Unio succissus Lea, Tr. Am. Phil, Soc, X, 1852, p. 275, pi. xxi, fig. 32 ; * Obs., V, 



1852, p. 31, pi. XXI, fig. 32.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, 

 p. 496.— *S0WERBY, Conch. Icon., XVI, 1866, pi. xxxiii, fig. 174.— -B. H. 

 Wright, Check List, 1888.— *P^tel, Conch. Sam., Ill, 1890, p. 169.— 

 * Simpson, Pr. U. S. Nat. Mus., XV, 1892, p. 29, pi. lxxi, fig. 5, 



* Margaron {Unio) succissus Lea, Syn., 1852, p. 24; 1870, p. 38. 



Wnio cacao Lea, Pr. Ac. N. Sci. Phila., Ill, 1859, p. 154; *J1. Ac. N. Sci. Phila., 

 IV, 1860, p. 344, pi. Lvi, fig. 169; * Obs., VIII, 1860, p. 26, pi. Lvi, fig. 169.— 

 *B. H. Wright, Check List, 1888. 



^Margaron ( Unio) cacao Lea, Syn., 1870, p. 54. 



West Florida ; southern Alabama. 



tQUADRULA PUMILA Lea. 



* Unio pmnilus Lea, Tr. Am. Phil. Soc, VI, 1838, p. 23, pi. vii, fig. 17; * Obs., II 



1838, p. 23, pi. vii, fig. 17.—* Troschel, Arch, fiir Naturg., V, 1839, Pt. 2, p 

 234.—* Hanley, Test. Moll., 1842, p. 185; * Biv. Shells, 1843, p. 185, pi. xxiii 

 fig. 13.—* Catlow and Reeve, Conch. Nom., 1845, p.-63.—* Conrad, Pr. Ac 

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

 1857, p. 495.— *Chenu, 111. Conch., 1858, pi. xix, figs. 1, la, lb. — * Sowerby, 

 Conch. Icon., XVI, 1866, pi. xxxvi, fig. 198.— *B. H. Wright, Check List 

 1888.—* P^tel, Conch. Sam., Ill, 1890, p. 164. 



* Margarita ( Unio) inmiilus Lea, Syn., 1836, p. 20; 1838, p. 17. 



* Margaron ( Unio) ])umilus Lea, Syn., 1852, p. 24; 1870, p. 37. 



Black Eiver, North Carolina. Only the type shell, a small specimen, 

 not in very good condition, has been seen by me. 



t?QUADRULA UTRICULUS Lea. 



* Unio utriculus Lea, Pr. Am. Phil. Soc, IV, 1845, p. 164; *Tr. Am. Phil. Soc, 



X, 1848, p. 69, pi. I, fig. 3; Obs., IV, 1848, p. 43, pi. i, fig. 3.—* Conrad, Pr, 

 Ac. N. Sci. Phila., VI, 1853, p. 259.—* B. H. Wright, Check List, 1888. 

 "^ Margaron ( Unio) utriculus Lea, Syn., 1870, p. 46., 



INorth Carolina. The specimen in the Lea collection which came from 

 Arkansas is not this species at all. 



'According to Marsh, who has examined the beak sculpture of Q. asJceivi. I have 

 never seen a specimen of the group in which it was not all eroded away. 

 Proc. ]Sr. M. vol. xxii 50 



