472 THE AMEBIC AN NATURALIST [Vol. XL VI 



and species from the Middle States region it has been 

 my opportunity to study in the present connection, the 

 following conditions are found. 



The stone roller (Campostoma anomalum) occurs in 

 the Mississippi Valley. In spring or early summer the 

 adult males sometimes have the entire upper surface of 

 the head and body covered with small tubercles, though 

 on the fins I have only found them extending on the rudi- 

 mentary dorsal rays. Though mostly attended with high 

 coloration, red being more or less conspicuous at most of 

 the bases of the fins, this is not always the case. Others 

 were found full of spawn, without tubercles, but in high 

 color. 



The red-bellied dace (Chrosomus erythrog aster) is one 

 of the most brilliant of all our common freshwater fishes, 

 occurring mostly west of the Alleghanies. The adult 

 spawning male has the entire head and body almost 

 everywhere covered with minute tubercles in the greatest 

 profusion. No females with tubercles have been secured. 



The fat-heads (Pimephales promelas and P. notatus) 

 are remarkable for their black heads, in the case of 

 spring males, besides having only a few large conspicuous 

 tubercles on the muzzle. The former species occurs only 

 west of the Alleghanies while the latter is found in all the 

 river-basins of Pennsylvania. The tuberculate males 

 seem to be the exception, or of short duration in that 

 condition, as among hundreds of examples of the latter 

 but few were found. 



The fall fish (Semotilus bullaris) and creek chub {S. 

 atromaculahis) are two well-known fishes. The former 

 occurs only east of the Alleghanies, and the fully adult 

 male is with brilliant rosy sides and mostly rosy fins. 

 Though reaching a length of nearly two feet, examples 

 three inches long have been taken with fully developed 

 eggs. The only tuberculated examples were all over a 

 foot in length, and had only their muzzles densely 

 covered with small tubercles. No nests were ever found 

 made by the small fish of three or four inches in length. 



