146 PAPERS ON ZOOLOGY OF MICHIGAN. 



The immense schools of mmnows here contained more red-belHed dace 

 than other species, but the followmg were also abundant in the schools : 

 Leuciscus neogaeus, Cayuga minnow, black-head mimiow, and silvery 

 minnow. 



The intestines of a number of the dace examined were filled with 

 humus and many diatoms, alga filaments, and some pine pollen. 

 Data on the food of the species is given by Forbes (1883), Needham 

 (1908) and Ellis (1914). 



10. Hyhognathus 7iuc1ialis Agassiz. Silver}- IMinnow. — This species 

 was found to be abundant at Station 55, in schools with red-bellied 

 dace and other species (see supra). A few were found in other parts 

 of the marsh lakes, except those east of Vermilion, where there were 

 none. They are also found in the beach ponds west of Vermilion. 

 Nowhere were they of full size, except at Station 55 where conditions 

 appeared unusually favorable for the species. One which was opened 

 had been eating some insects including chironomid larvae and mud 

 rich in diatoms. 



The hundred or so captured measured from 1 to 3.3 inches in length. 

 One of the larger ones was colored as follows: light-yellowish olive 

 above, below white with yellowish reflections, a distinct black lateral 

 band, sides not silver}' as the}' usually are in this species. 



11. Pimephales promelas Rafinesque. Blackhead Minnow. — The 

 species is similar in distribution to the red-bellied dace and the silvery 

 minnow in that it is abundant in the west group of marsh lakes near 

 Vermilion and relatively scarce and of small size in the east group. Like 

 the others, it also finds optimum conditions in marsh bays (Station 52, 

 53, and 55). It was common in the beach ponds at Mason's Creek, 

 and some were found in Little Lake. 



Over two hundred of these minnows were taken; they measured 

 from .7 to 2.5 inches in length. One of the larger specimens was of a 

 light-yellowish olive above, fading to the white of the lower parts, and 

 had a black, lateral stripe. 



Mud rich in diatoms was found in a few intestines examined. Forbes 

 (1883) found the species eating mud and insects, and Fowler (1908) 

 states that it eats green algae and mud. 



12. Semotilus atromaculatus (Mitchill). Horned Dace. — Horned 

 dace were uncommon in the Whitefish Point region. Small specimens 

 .7 to 2.7 inches long were caught in Beaver Lake, in Cranberry Creek 

 and in the beach ponds west of Vermilion. The last named place was 

 the only one in which they were found to be at all common. 



13. Leuciscus neogceus (Cope). This abundant species of minnow 

 also belongs to the red-bellied dace association, and is very similar to 

 it in distribution, except that it is fairly common in the east marsh 



