Lake Maxinkuckee, Physical and Biological Survey 443 



naubee Darter, which is there the most common of the darters ex- 

 cept Percina caprodes. Not a great number were obtained during 

 the seining operations, but nearly every rakeful of Chara brought 

 up during the winter through the ice contained 1 or more of these 

 fishes. This darter probably spends most of its time among the 

 Chara and thus escapes the net. It prefers hiding under weeds to 

 lying on open bottom, and is commonly not seen before being cap- 

 tured. In the short matted Chara found so abundantly in the 

 shallow water of the lake, it is doubtless abundant. In the open 

 places it may frequently be seen lying still on the sandy bottom, 

 or occasionally darting to cover. 



The Iowa Darter probably spawns late in April or early 

 in May. Females taken April 27, 1901, were examined and found 

 to be full of spawn. The ovaries of the specimen examined were 

 each a club-shaped mass narrowed sharply behind, truncate and 

 concave in front, its anterior margin adjusted in outline to that of. 

 the well-filled stomach, and surrounded by a firm membrane. The 

 length of the fish examined was 50 mm., the length of the egg-mass 

 10 mm. The mature eggs, which may have been shrunken some, 

 but probably little by the preservative, were bright yellow, 32 to 

 the inch, and 115 in number in one ovary; probably about double 

 that number in the whole fish. Mixed in with them was a large 

 number of minute ova, probably representing the next year's 

 product. 



More than any other species of fish in the lake, except some 

 of the minnows, this fish is afi'ected with the affliction known as 

 Diplostomiasis characterized by small round black spots in the 

 skin, each indicating the cyst of a distomid which is said to reach 

 its mature form in the stomachs of water birds. 



The only food found in the stomachs examined consisted of in- 

 sects and insect larvje. These darters are occasionally found in 

 the stomachs of other fishes. The bass sometimes eat them. 



On comparing our Lake Maxinkuckee material with specimens 

 of E. iowR', from Creighton, Nebraska, and with current descrip- 

 tions, the Maxinkuckee specimens appear to be less fully scaled on 

 the cheeks and opercles. 



The squamation of these parts is exceedingly various as re- 

 gards degree of development as well as number of scales. The 

 skin of these parts may be entirely smooth or naked ; the scales in 

 their simplest form are represented by raised tubercles, which are 

 usually rather numerous and regularly arranged, which show well 

 on a wet specimen by reflections. In a more developed stage they 

 consist of embedded smooth circular scales which bear some re- 



