FISHES OF NEW YORK 337 



pugnacious, and, when these fish are kept in confinement, great 

 mortality is caused by their quarrels. The species is abundant 

 in small streams, where it secretes itself among aquatic plants 

 and is always alert to attack small fishes and insects. Speci- 

 mens have recently been obtained from an artesian well in 

 South Dakota, the well having a depth of 700 feet. From this 

 :great depth the fish were brought up in full strength and vigor, 

 and they were kept in an aquarium several months afterward. 

 A similar occurrence has been recorded by Mrs Eigenmann, in 

 the Prooeedings of the National Museum for 1883, p. 217, of 

 Williamson's stickleback at San Bernardino Cal. The well in 

 this case was only 191 feet deep. There is no doubt that the 

 :fish reach the wells through streams which become subter- 

 ranean in a certain part of their course. 



This species is a nest-builder and is vigorous in the defense 

 of its eggs and young. 



This fresh-water stickleback appears to live better in bal- 

 anced tanks than in flowing water and is not hardy in captivity. 

 It feeds readily on chopped hard clams and Gammarus, the 

 latter being one of its natural foods. 



169 Eucalia inconstans cayuga Jordan 

 Cayuga Lake SticJclehack 



JEucalia inconstans cayuga Jordan, Man. Yert. ed. 1, 249, 1876, Cayuga 

 Lake, Ithaca, N. Y.; Meek, Ann. N. Y. Acad. Sci. IV, 312, 1888; 

 Jordan «& Evermann, Bull. 47, U. S, Nat. Mus. 744, 1890. 



According to Dr Jordan, this variety has longer ventral 

 spines than the common brook stickleback, these being as long 

 as the pubic bones (two thirds as long in inconstans). 

 The size is generally smaller, but the fin rays are the same as 

 in inconstans. 



The variety occurs in small brooks and in the lakes about 

 Ithaca and Syracuse N. Y. 



Genus pygosteus Brevoort 



This genus is characterized by the presence of 9 to 11 

 divergent spines and by the weakness of its innominate bones. 



