206 MEMOIRS OF THE CARNEGIE MUSEUM. 



Ortmann, 1913a, p. 367 et seq.). It is found everywhere in the drainage of the 

 Ohio and in that of the upper Mississippi. There are sections, where records are 

 scarce or missing, as for instance in Kentucky, and its absence in the upper Kanawha 

 system in West Virginia and Virginia should be noted (See Ortmann, 1913, pjx 

 308 and 367). It seems to be rare in the Cumberland (Wilson & Clark, 1914), 

 but in the upper Tennessee system in Tennessee and Virginia it is common. 



In a westerly and southwesterly direction it goes across the Mississippi, and 

 has been found as far west as eastern Nebraska (Tryon, 1868); in Kansas, as 

 far as Saline Co., in the Kansas-drainage, and Reno County, in the southern 

 drainage (Scammon, 1906). From Arkansas it has been reported by Call (1895) 

 and Meek & Clark (1912), and it is represented from the Ozark streams, the Saline 

 and Ouachita Rivers in the Carnegie Museum (previously reported from Ouachita 

 by Vanatta, 1910, and Wheeler, 1918). It is also present in Oklahoma (Carnegie 

 Museum). Frierson (1899) reports it from a tributary of Sabine River in De Soto 

 Parish, Louisiana, and according to Simpson it goes to central Texas (Vaughan, 

 1893, does not mention it from northwestern Louisiana, and Singley, 1893, does 

 not mention it from Texas). 



Records from the southern Atlantic and Gulf states are lacking, though 

 Simpson cites Tyner, Tuscaloosa Co., Alabama; and a number of allied forms, 

 separated as species, are credited to Georgia, Alabama, and Mississippi. I can- 

 not judge of these; but I may mention, that specimens from the Alabama-drainage 

 in the Carnegie Museum, partly collected by H. H. Smith, partly by myself, seem 

 to differ, and to represent possibly two other species: S. connasaugaensis (Lea) 

 (= alabamensis Lea = gesneri Lea), and *S. spilhnani (Lea). Both have the 

 pseudocardinal teeth better developed than S. edentulus. 



139 



Subfamily LAMPSILIN.^ (v. Ihering, 1901) Ortmann (1910). 

 Ortmann, 1910, p. 118; 1911, p. 337; 1912, p. 300. 



Key to the Genera of the Lampsilin.e. 

 «!. Marsupium not kidney-shaped. Ovisacs subcylindrical or very slightly compressed. Placentae 

 generally very solid. Inner edge of mantle in front of branchial opening, not distinctly differ- 

 entiated. Shell rounded, ovate, subelliptical, sometimes with sculpture upon the disk. Male 

 and female shells practically alike. 



61. Marsupium occupying the whole of the edge of the outer gill, folded. .Placentae club-shaped, 



short. Shell subelliptical, smooth Ellipsaria. 



62. Marsupium occupying only a part of the outer gill. Placentae subcylindrical, elongated or very 



long. Shell more or less rounded, generally with tubercles. 



"' V. Ihering first coined tliis subfamily-name, but places some of the genera belonging here in liis 

 subfamily Quadrulinm. 



