«7 



catfish manages to tear from its shell. The shells recently emptied 

 were sometimes brought out by seines in great numbers. Young 

 and adults were seen in the sloughs and lakes, one of the former 

 measuring .62 in length. A valve of a large one picked up at the 

 edge of Wood Slough measured' 6.75 inches in length. 



Localities: Lily Lake, Broad Lake, AVood Slough. 



Anodonia imbecilis, Say. 



{A imhccilis, Say, New Harmony Disseminator, 1829.) 



Young examples about an inch long were very common in Wood 

 and Willow Sloughs. The adults were not seen. 



Localities: Willow Slough, Lily Lake, Wood Slough. 



Unto fdatiis, Say. 

 [U. alakis, Nich. Enc, Am, ed., iv, f. 2, 1816, 1818, 1819.) 

 Taken in Willow Slough and Lily Lake. 



Unto gracilis, Barnes. 



( U. gracilis, Barnes, Silliman's Jour, ii, 174, 1823. ) 

 Taken in Willow Slough. 



Unio Icevissimiis, Lea. 



{U. locvissimus. Lea, Am. Phil. Soc. iii, pi. 13, f. 23; Obs. on 

 Genus Unio, L) 



This is one of the large compressed species with angular ex- 

 pansions of the dorsal or hinge portion of the shell. The young 

 are especially noticeable because of the large relative size of these 

 angular processes, and were very common in portions of Wood 

 and Willow Sloughs. In Lily Lake, also, they were numerous, but 

 were not seen elsewhere. 



Unio parvus, Barnes. 



( U. parvus, Barnes, Silliman's Jour., vi, 174, 1823. ) 



Examples of this small clam 1.62 inches long were taken in 

 Harkness Slough. It was not observed outside the levee. 



INSECTA. 



Unfortunately, little has been done on aquatic insects by ento- 

 mologists, beyond describing and naming the species, and a search 

 through the writings of American and foreign authors does not 

 yield much of the particular kind of knowledge of which practi- 

 cal fish work stands in need. The food habits and transforma- 

 tions especially have been greatly neglected. We can not there- 

 fore give such an account of the species collected as could be 

 wished, but shall aim to add something to a knowledge of food 

 habits in certain cases, and to point out, as clearly as we can in 

 a brief paper, the forms whose acquaintance the economic ichthy- 

 ologist needs to make. 



