Ill. COTTOIDS OF NORTH AMERICA. 49 
§ 4. Sprctes wits Turez Sorr Rays 10 THE VENTRALS. 
Vil. COTTUS GRACHLIS, Hecx. 
Prats I. Figs. 11 and 12. 
Syn. Cottus gracilis, Heck. Ann. d. Wien. Mus. II., 1837, p. 148.—Girarp, Proc. Amer. Ass. Adv. 
Se. IL., 1850, p. 411; and, Proc. Bost. Soc. Nat. Hist., TII., 1850, p. 189. 
Uranidea quiescens, Dexay, New York Fauna, 1842, p. 61, Pl. V. Fig. 14. 
Cottus gobio, Ayrus, Bost. Journ. Nat. Hist., V., 1845, p. 121, Pl. XI. 
The history of this species is quite interesting: described abroad for the first time 
as the second species of Cottus, peculiar to this country, its description remained 
unknown for years on this side of the Atlantic, and when Dr. Dekay published 
the Fauna of the State of New York, he even lost sight of the fresh-water Cotti, 
and proposed for it a new genus. Next we find Mr. Ayres restoring this species to 
its true genus, and yet misled on the question of the species, an error which he 
would not have committed if the paper of Mr. Heckel had been at his command. 
This is one of the small species of the genus, scarcely exceeding three inches in 
length. The specimens which we have had under examination had not quite that 
size. The general appearance is fusiform, slender, less so, however, than C. boleoides ; 
but on the other hand, it is shorter than the latter, resembling more in shape C. 
Bairdii. The greatest depth of the body is contained a little more than six times 
in the total length; a little less thick than deep anteriorly, it diminishes gradually 
towards the tail, though more rapidly in thickness than in depth. The latter, on 
the peduncle of the tail is reduced to the proportions of one-thirteenth of the total 
length. 
The head forms about the fourth of the total length. The occipital region is 
slightly sloping backwards, thus giving to the neck a depressed appearance. From 
the orbits to the end of the snout, the head is rather rounded, although not 
abruptly truncated. The eyes, circular in form, are one-sixteenth of an inch in 
diameter, which is comprised nearly four times in the length of the head. Their 
frontal distance is only the half of their diameter. The anterior nostrils are situated 
midway between the orbits and the snout; the posterior ones are higher up, and 
close to the eyes. The mouth is proportionally great; its angles nearly reach the 
pupil. The lips are well developed, but the teeth are not very conspicuous. Pala- 
tine teeth have been assigned to this species, but are not to be found in the specimen 
figured. There is nothing which resembles teeth on the tongue as ascribed to 
Uranidea quiescens. The preopercular spine is but little prominent; that of the 
subopercular is constantly concealed under the skin. The gill openings are oblique; 
the isthmus is a quarter of an inch wide. There are constantly six branchiostegal 
rays, even in the specimens in which Dr. Dekay signalizes seven. 
The origin of the first dorsal is six-eighths of an inch distant from the extremity 
of the snout; it is not quite half an inch long, and its height is less than the half 
of its length. Its upper edge is rounded and convex; the first and second rays 
being a little shorter than the third and fourth; there are eight rays in all; the 
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