ftASTEEOSTElD^. — XCVIH. 259 



XX Dorsal spines in tlie same line, the lowest in front ; ventral 

 plate single, on the middle line of abdomen; caudal 



peduncle stouter Bdcalia, 3. 



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

 not in a right line Pygosteus, 4. 



/. GASTEROSTEUS, Linn»us. Mailed Sticklebacks. 

 1. 6. 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. Foub-Spinbd 

 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. pygmma, ( Agassiz ) 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 caTudal 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 



