GASTEROBTEID^. — XOVIII. 259 



:}::}: Dorsal spines in the same line, the lowest in front; ventral 

 plate single, on the niidcUe line of abdomen; caiulai 

 peduncle stouter. . ... . . Eucalia, 3. 



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



not in a right line. Pygosteus, 4. 



/. GASTEROSTEUS, Linni^us. Mailed Sticklebacks. 



1. G. noveboracensis, C. & V. New York Stickle- 

 back. Maine to Cape Hatteras, coastwise; sometimes 

 ascending- streams. 



2. APELTES, ])eKay. Naked Sticklebacks. 



< G aster osteiis^ L. 



1. A. quadracus, (Mitch.) Brevoort. Four-Spined 

 Stickleback. Abundant, with the preceding. 



2. EUCALIA, Jordan. Nest - Building Sticklebacks. 



1. E. inconsians, (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, ]0; 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-buildina: habits. 



Var. pygmcea, ( Agassiz ) Jordan. Lake Superior 

 Stickleback. Depth 3f in length; head 3-J; 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, G; A. I, 6. L. 

 Superior. 



Var. cayuga, Jordan. Cayuga Lake Stickleback. 

 Head 3-g- in length; depth 4:^; spines all high; caudal 



