Lake Maxinkuckee, Physical and Biological Survey 331 



to Texas, and is usually abundant, especially west of the Missis- 

 sippi. It is very variable and is closely related to both A. natalis 

 and A. nebulostis. It is, however, a smaller fish and can usually 

 be known by the fewer rays in the anal and by the marked contrast 

 between the pale anal rays and the dark interradial membranes. 



This species is not at all common in Lake Maxinkuckee, only a 

 few individuals having been seen there, and the majority of these 

 were obtained in the Outlet and in Lost Lake. 



Head 3.5 ; depth 3 to 4 ; eye 8 to 9 ; snout 3 ; D. I, 6 ; A. 17 to 19. 



Body short and stout; head blunt; mouth moderate, jaws sub- 

 equal; origin of dorsal midway between tip of snout and origin 

 of adipose fin, dorsal spine long, 2 in head, equalling pectoral spine ; 

 anal short, its base 4 to 5 in length of body, its rays 1.75 in head; 

 barbels long, maxillary barbel much longer than head. 



Color usually almost black; anal rays pale, the membranes 

 black, the contrast being quite marked. Size a foot or less. 



9. MAD TOM; TADPOLE CAT 



SCHILBEODES GYRINUS (Mltchill) 



(Plate 5) 



This little fish is common from the Hudson River westward 

 through almost the entire Mississippi Valley and upper lake re- 

 gion. In Lake Maxinkuckee it is rather common. It seldom 

 reaches a length of more than 3 inches here, though specimens 5 

 inches long have been reported from elsewhere. Of 35 examples 

 measured at the lake the largest was 2.6 inches long, the short- 

 est .9 inch, and the average was 1.74 inches. Several of these 

 examples were mature fish. This is the only species of the genus 

 occurring in Lake Maxinkuckee, although other species are com- 

 mon in the various streams of Indiana. It may be readily kno\\Tii 

 from the young of any of the other catfish found there by its 

 adnate adipose fin which is continuous with the caudal fin, and also 

 usually by its color. 



It was found by us both in the main lake and in the small one. 

 It is not at all uncommon in shallow water near shore, where we 

 would frequently find it more or less completely secreted in the 

 Chara or in patches of Nitella or dwarfed Potamogeton. Speci- 

 mens were also brought up with vegetation by the dredge or 

 grapple from depths of 8 to 16 feet. Throughout the winter rak- 

 ing in the Chara would frequently bring up one or more of these 

 fishes. With the exception of the Iowa darter this is one of the 

 most common fishes taken in this manner. They were also often 



