﻿ANODONTA 419 



sharply, doubly looped, the bases of the loops nearly or quite 

 nodulous ; posterior ridge full, frequently more or less double 

 and ending behind in a rounded or feebly biangulate point at 

 the median line ; post-dorsal wing low, obliterated in old spec- 

 imens ; upper anterior edge either slightly angled or rounded ; 

 base line curved ; epidermis greenish-brown or browaiish-green, 

 rarely faintly rayed, but showing about three broad, dark rays 

 on the posterior slope ; beak cavities varying from shallow to 

 moderateh' deep, not compressed ; nacre bluish-white, rarely 

 tinted purj>le, sometimes a little thickened in front. 



Length 135, height 68, diam. 40 mm. 



Length 102, height 57. diam. 35 mm. 



Length 146, height yi, diam. 57 mm. 



Entire Mississippi .system ; Upper St. Lawrence drainage ; 

 Red River of the North ; Lake Winnipeg ; ^Manitoba ; south- 

 west to Texas ; southeast to Pennsylvania? 



Type locality. Fox River of the Wabash. 

 Anodonta grandxs Say, N. Harm. Diss., H, 1829, p. 341.— 



C1.ESSIK, Conch. Cab. Ano., 1873, p. 96. pi. xxx, figs, i, 2.— 



Baker, Moll. Chicago, W. L 1898, p. 51, pis. ti; 111, fig. i; 



IV, fig. T. — Simpson, Syn., 1900, p. 641. 

 Margarita (Anodonta) grandis Lea. Syn., 1836, p. 52; 1838, 



p. 31- 

 Anodon grandis Sowerby. Conch. Icon.. X\ IT, 1870. pi. i, 



fig. I. 

 Margaron f Anodonta) grandis Lea. Syn.. 1852, p. 51; 1870, 



p. 81. 

 Anodonta oz'ata Lea. Tr. Am. Phil. Soc, \l. 1838, p. 2, pi. 11, 



fig. 2; Obs., II, 1838. p. 2, pi. II. fig. 2.— Clessin, Conch. 



Cab. Ano., 1874, p. 121. pi. xxxix, figs. 2. 3. 

 Margarita f Anodonta) ovata Lea. Syn., 1836, p. 52: 1838. p. 



30- 

 Anodon orata Cati.ow and Reeve, Conch. Xom.. 1845. P- ^7- 



Margaron (Anodonta) ovata Lea, Syn., 1852. p. 50; 1870. p. 



80. 

 Margarita (Anodonta) saluionia Lea, Syn.. 1836. p. 51 : 1838, 



p. 30. 



