GASTEBOSTEID.E. XCVTLT. 259 



\\ Dorsal spines in the same line, the lowest in front ; ventral 

 plate single, on the middle line of abdomen; caudal 



peduncle stouter EUCALIA, 3. 



** Dorsal spines 7 or more; sides mailed or not; dorsal spines 



not in a right line PYGOSTEUS, 4. 



/. GASTEROSTEUS, Linnaeus. MAILED STICKLEBACKS. 

 1. G. noveboracensis, C. & V. NEW YORK STICKLE- 

 BACK. Maine to Cape Hatteras, coastwise; sometimes 

 ascending streams. 



2. APELTES, DeKay. NAKED STICKLEBACKS. 



< Gasterosteus, L. 



1. A. quadracus, (Mitch.) Brevoort. FOUR-SPINED 

 STICKLEBACK. Abundant, with the preceding. 



2. EUCALIA, Jordan. NEST -BUILDING STICKLEBACKS. 



1. E. inconstans, (Kirtland) Jordan. BROOK STICKLE- 

 BACK. OHIO STICKLEBACK. Head about 3 in length; 

 depth nearly 4; spines rather low; ventral spine about 

 equal to eye; color olivaceous, marbled with darker; 

 males in spring jet black, finely punctate; D. Ill to 

 V I, 10; A. I, 10; length 2$ inches. Ohio to Minne- 

 sota and Kansas, chiefly northward; abundant in sluggish 

 streams; an interesting species, remarkable for its pug- 

 nacity and for its nest-building habits. 



Var. pygmcea, ( Agassi z ) Jordan. LAKE SUPERIOR 

 STICKLEBACK. Depth 3f in length; head 3; caudal 

 peduncle short and stout; body shorter and deeper than 

 in the preceding; vent much nearer tip of caudal than 

 snout; color similar; D. Ill or IV I, 6; A. I, 6. L. 

 Superior. 



Var. cayuga, Jordan. CAYUGA LAKE STICKLEBACK. 

 Head 3 in length; depth 4; spines all high; caudal 



