386 REPORT OF THE COMMISSIONER OF FISHERIES. 



sess more or less dermal pigment and thus are colored much like ordi- 

 nary fishes. There are four pyloric coeca, and each species possesses 

 tactile ridges. 



KEY TO THE SPECIES OF CHOLOGASTER. 



a. Eye large, contained 5.5 times in the head; species of dark coloration. 



6. Sides with 3 well-defined longitudinal lines, the middle one broadest; tactile 



papillae very smalL cornutus. 



bb. Dark lines present on the sides of the body but much fainter than in cornutus; 



tactile papillae large papilUfcrus. 



aa. Eye very small, contained 10 times in the head; coloration faint agassizii. 



Chologaster cornutus Agassiz. 



The body of this species is rather slender, its length being contained 

 from 5.25 to 6.5 times in its length; head considerably depressed, 3 to 

 3.5 in body; mouth large, terminal, oblique, the lower jaw projecting; 

 maxillar}^ extending to near front of eye; eye small, about half length 

 of snout and so located as to be able to see upward as well as sidewise; 

 gill-membranes united and loosely joined to the isthmus, reaching back 

 to or covering the vent; pectoral 1.5 in head and 1.4 in distance from 

 snout to front of dorsal fin; caudal fin considerably pointed, about 

 equal to head; dorsal with 8 to 9 rays, its front nearer base of caudal 

 than tip of snout; anal with 8 to 9 rays, inserted almost directly 

 under dorsal; scales very small, C3'cloid and not arranged in regular 



rows; no lateral line; tactile ridges pres- 

 . ..p--^^^^ ent but very small; about 70 scales in a 

 "^^ _ _ r-^^.ci^^^^ straight line along side from head to 



""^ caudal fin; head naked. Color dark 



Cut 11. — Vhohxjastcv cornutus. t i -i i i • 



brown above, lighter on sides and white 

 on belly; side with 3 narrow, well-defined longitudinal dark lines, the 

 middle one, which is deepest and widest, extending across head and 

 eye to tip of snout, upper line nearer to back than to middle line; a 

 dark black blotch on base of caudal; remainder of caudal variously 

 mottled with black. There is sometimes a white crossbar about the 

 middle of the caudal, but this ma}^ be reduced to 2 small white spots; 

 tip of fin frequently white. In some specimens the back is entirel}^ 

 black and the dorsal fin white, spotted with black. The color, no 

 doubt, varies much with the conditions. Length of the largest speci- 

 men known, 1.8 inches. 



This little fish inhabits the swamps of the southern United States 

 from the Dismal to the Okefinokee. It is said to be abundant locall}^, 

 but at present there are very few specimens in the museums, so far as I 

 am able to learn. Those examined were f ro'm the Dismal Swamp, Vir- 

 ginia, and were kindl^^ loaned by the United States National Museum. 



The specimens described as C. avitus prove to be a variation of C. 

 cornutits, the difference being chiefly one of color. ^ 



« Jordan and Evermann, Fishes of North and Middle America, I, 703, 1896. 



