IOWA ACADEMY OF SCIENCES. 
8S 
TABLE I. SEASONAL AND SEXUAL DISTRIBUTION OF MATERIAL. 
SPECIES 
April 
May 
July 
Aug. 
Sept. 
Oct. 
Nov. 
M. 
F. 
M. 
F. 
M. 
F. 
M. 
F. 
M. 
F. 
M. 
F 
M. 
F. 
l6 
8~ 
j 
20 
14 
2 
15 
13 
2 
2 
3 
IT 
13 
-+ 
6 
13 
4 ! 
6 
4 
6 
I 4 
9 
39 
iy 
2 i 
3 
Quadrula plicata Say 

7 
10 
32 

.... 
... 

4 
8 
A 
6 
5 
10 
Quadrula ru biginosa Lea 
i4 
1 7 
12 
5 
2 
Quadrula ebena Lea... 
6 
10 j 
12 
* 
Unio gibbosus Bar 
l8 
9 i 
3 
3 
Unio complanatus Sol 
36 
29 
43 
27 
Alasmodonta confragosa Say. 
Q ' 
4 
Alasmodonta companata Bar. 
13 
12 
6 
7 
2 
3 
5 
6 
3 
4' 
Alasmodonta rugosa Bar 
/ 
I 
6 
1 
5 
3;, 
Alasmodonta marginata Say... 




16 
20 
6 
!' 
1 

Alasmodonta undulata Say.. . 
2 
1 
Alasmodonta tappaniana Lea.-. 
I 
Strophitus edentulus Lea. 
2 
2 
j 
2 
2 
1 
Anodonta imbecilis Say 
4 
4 
3 
Anodonta suborbiculata Say . . 
18 
sj/ 
2 
Anodonta grandis Lea. 
2 
2 
2 
T/r 
Anodonta corpulenta Coop 
6 
2 
18 
II 
6 
3 
Obliquaria reflexa Raf. 
2 
IT 
6 
j 
Plagiola securis Lea 
0 
-*■4 
5 
Plagiola elegans Lea 
8 
12 
14 
" _ 8 
Plagiola donaciformis Lea 
5 
7 
x8 
T 
Lampsilis parvus Bar 
6 
*T 
25 
x 
Lampsilis ellipsis Lea 
2 
2 i 
2 
2 
1 
Lampsilis ligamentinus Lam... 
J 
A 
5 
6 
3 
”8 
4 
24 
21 
Lampsilis luteolus Lam .. 
4 
3 
6 
6 
8 
1 
Lampsilis nasutus Say 
2 
2 
Lampsilis anodontoides Lea 
4 
2 
11 
32 
1 
1 
1 
Lampsilis rectus Lam 
8 
10 
6 
3 
1 
6 
5 
4 
2x 
Lampsilis ochraceous Say.. 
1 
Lampsilis ventricosus Bar 
3 
7 
8 
7 
"28 
9 
”6 
4 
19 
19 
Lampsilis alatus Say 
2 
A 
4 
23 
9 
3 
3 
1 
Lampsilis laevissimus Lea... 
4 
3 
1 
Lampsilis eracibs Bar 
.. 
TC 
3 
23 
20 
11 
11 

6 
2 
3 
2 
