60 Trans. Acad. Set. of St. Louis. 



Anodonta ferruyinea Lea. Trans. Am. Philos. Soc, 

 2d series, Vol. VIII, 1840, p. 289, PI. XIX, Fig. 43. 

 Described from Simon's Creek, Indiana. 



Anodonta tetragona Lea. Trans. Am. Philos. Soc., 2d 

 series, Vol. X, 1845, PI. VIII, Fig. 25, p. 82; described 

 from Alexandria, Louisiana. 



Anodonta sJtafferi%na Lea. Trans. A.m. Philos. Soc, 

 2d series, 1852, Vol. X, PI. XXVI, Fig. 50, p. 288 ; de- 

 scribed from Horn Lake creek, Tennessee, and FlatKock 

 creek, Indiana; Reeve, Anodon Plate XXXV, Fig. 143, 

 Conchologia Iconica, Vol. XVII. 



Anodonta arkansasensis Lea. Trans. Am. Philos. 

 Soc, 2d series, Vol. X, 1852, p. 293, PI. XXIX, Fig. 

 56. Described from Kansas. 



Alasmodonta rhombica Anthony. Am. Jour. Conchol- 

 ogy, Vol. I, 18G5, p. 158. 



Anodon annulaius Sowerby. Reeve, Conchologia Icon- 

 ica, Vol. XVII, Anodon Plate XVIII, Fig. 67. This 

 figure and description are based upon a specimen in the 

 Museum Cuming, from an unknown habitat ; it shows the 

 characters of the beaks of edentula, and is without 

 question that form. 

 This is the most common and abundant Anodonta in the 

 west. The characters of the dorsal margin are such that it 

 is often mistaken for a Margaritana as, indeed, was the 

 case when originally described. Subjected to a vast variety 

 of environmental conditions, it is not surprising that very 

 many names have been applied to its differing forms. It is 

 not easily separated, at times, from the form called Anodonta 

 undulata Say, which is supposed to be entirely confined to 

 the regions east of the Appalachians, or to waters draining into 

 the Great Lakes. 



Reeve's Fig. 60, Vol. XVII, Conchologia Iconica, Plate 

 XVII, is not Anodonta edeiitula, but is something else. 



The species has occurred in collections made in the St. 

 Francis river, at Wittsburg, and in the Saline, at Benton ; a 

 single imperfect specimen was picked up in a small stream, 

 without a name, in the southeastern part of Craighead 

 county. 



