246 REPORT OF STATE GEOLOGIST. 



Europe and North America; in the latter, from New York to Lake 

 Michigan and north to Greenland. Found in both salt and fresh waters. 

 Lake Michigan {KJ, 1874); Calumet River and Lake Michigan (i.^, '80, 

 69.) 



This species is said by Dr. Jordan to be rather abundant in Lake Mich- 

 fgan in deep water. Dr. Forbes has examined the food taken by it.- 

 This consists of aquatic larvae of insects and entomostraca, with a consid- 

 erable percentage of vegetable matter. 



Genus EUCALIA Jordan. 



Dorsal spines five, erecting in a straight line. Body not furnished 

 with bony plates. * 



EUCALIA INCONSTANS (Kirt.). 



* Brook Stickleback. 



Gasterodeus inconstans, Jordan aud Gilbert, 1882, 6', 394; Eucalia in- 

 constans, Eigenmann, 1889, 1, 238. 



Body deep and compressed; depth in the length four and one-half. 

 Head in length three and one-half. Eye in head three and three-quar- 

 ters. Mouth small, oblique. Caudal peduncle short, slender, and with- 

 out keel. Dorsal rays IV, I, 10, the spines not leaning to right and left 

 when erected. Anal rays I, 10. Olivaceous, with some mottlings of 

 brown. Males in breeding season black, with more or less of red. 

 Length about two and one-half inches. 



New York, Indiana, aud Kansas, north to Greenland. In Indiana 

 has been taken by Prof. W. P. Shannon in Decatur County (.23, '88, 

 57); in Wabash County by Prof. Ulrey (34, '93, 96). 



Dr. Jordan (3, 998) states that in the aquarium these fishes are quar- 

 relsome, aud in default of other game they will destroy one another. The 

 males during the breeding season build a nest for the eggs and vigorously 

 defend it. They are said to frequent brooks; but Mr. McCormick speaks 

 of finding them in two places in Lorain County, Ohio, in "hot, grassy 

 holes," haunts quite different from those described by Kirtland and Jor- 

 dan, 



Forbes has investigated the food of the species. He says (14, No. 2, 

 78, 14, No. 6, 69) that it consists of entomostraca, insects and some algse. 

 One had eaten some eggs, probably those of some mollusk. This fish is 

 also charged by other authors with destroying the eggs of other fishes. 

 Some species of sticklebacks take vengeance on the fishes w'hich may at- 

 tempt to eat them. Pennell in his " Book of the Pike" states that the 

 pickerel is often killed by attempting to swallow the sticklebacks. This 

 on being attacked erects the spines, so that the httle fish sticks in the 

 throat of the larger fish and leads to its death. 



