ORTMANN: monograph of the naiades of PENNSYLVANIA. 147 



In the Tennessee-drainage it is extremely rare, but certainly' extends into northern 

 Alabama. It is also very rare in the Cumberland-drainage, but has been reported 

 by Wilson & Clark (1914) from ponds at Clarksville, Montgomery, Tennessee, 

 and from Stones River, in Rutherford Co., Tennessee. 



In the southwestern part of its range this species seems to become more 

 decidedly a pond- or lake-form. Call (1900) makes the statement that in Indiana 

 it is found in the ponds along the Ohio and Wabash, and that it occurs in the rivers 

 in the northwestern part of the state, that is to say, in smaller streams; this cor- 

 responds well with what we have observed in Pennsylvania. But west of the 

 Mississippi pond-forms prevail, and assume special shapes, which I cannot discuss 

 here, for they require much more detailed study (compare Wheeler, 1918, p. 121). 



Anodonta grandis footiana (Lea) (1840). 

 .Anodonta grandis footiana (Lea) Simpson, 1914, p. 422. 



Plate X, figs. 3, 4. 

 Records from Pennsylvania: 



Ortmann, 1909fe, p. 202. 



Characters of variety: According to Baker (1898a, pp. 51 and 53), this variety 

 differs from Anodonta grandis by the greater inflation of the shell, chiefly in the 

 anterior and umbonal region, and by the finer beak-sculpture, which consists of 

 onlj^ four bars (while there are five in A . grandis) . 



This is the most concise statement of the differences of the two forms that 

 has ever been made. But with regard to the number of the bars in the beak- 

 sculpture it is to be remarked that in the light of my material, this is quite variable 

 (from four to six bars in footiana as well as grandis), but with a stronger tendency 

 toward the smaller figure in footiana. 



In other respects A. grandis footiana behaves much like A. grandis, and varies 

 greatly in shape (more or less elongated), thickness, and color (from yellowish 

 and greenish to brownish and reddish) ; it lacks the dark green and blackish tints 

 found so often in grandis. Rays are generally entirely missing. The size is 

 inferior to that of grandis. 



L. H. D. 



2. do. " " do 



■3. do. " " do 



4. Beach Pool E. & F., Cat. No. 61.-1181 



5. do. " " do. 



6. " Big Bend," Cat. No. 61.4188 



7. do. " " do 



