FISH OF ONTARIO. 35 



erate. Sexual changes very slight, no red or black pigment distinguishing 

 the males in spring. 



Subgenus HYBOGNATHUS. 



(28) Silvery Minnow. 



(Hybognathus nuchalis.) 



Body rather slender ; head rather short, the profile evenly curved ; eye 

 moderate ; lateral line decurved. Caudal moderate in size and deeply forked. 

 Scales, 6-38 to 39-4. Teeth, 4-4, long, much compressed, with a long 

 oblique grinding surface. Intestines seven to ten times as long as the 

 body. 



Colour above, olivaceous green, translucent; sides silvery, with bright 

 reflections ; fins unspotted. Length about six inches. 



Has been taken in the Lake Ontario region of New York State and 

 will probably also occur here. 



Genus PIMEPHALES. (Fat-head Minnows.) 



Body rather robust, little compressed; head short and rounded, mouth 

 small, inferior; upper jaw protractile; no barbel; teeth 4-4, with oblique 

 grinding surface, usually only one of the teeth hooked ; dorsal over ven- 

 trals, its first (rudimentary) ray separated from the rest by membrane, 

 not joined to them as usual in Minnows, this character most distinct in 

 adult males, in which the skin of the first ray is thickened ; anal basis 

 short ; intestinal canal elongate ; peritoneum black ; pseudobranchiae pre- 

 sent ; scales rather small ; lateral line complete or variously incomplete. 

 Size small. Breeding males with much black pigment and with large 

 warts on the head. 



Black-head Minnow. {Fiinephales proiuelas.) 



(29) Blackhead Minnow. Fathead. 



(Pimephales promelas.) 



Body short, deep, and moderately thick ; head short, with a very 

 obtuse snout; mouth very small terminal, slightly oblique. Scales, 9-45 

 to 49-6. 



4 F. 



