THE FISHES OF ALASKA. 307 



This species is doubtless common throughotit Alaska, but being t'ouml further up the streams away 

 from brackish water and in places not usually visited by collectors, it has not been taken aliundantly 

 or recorded from many places. 



129. Cottus cognatus Richardson. Gnat Bear Lake Bullhead. 



One of the most interesting results of the side trip made to the headwaters of the Yukon was the 

 securing of a fine series of specimens of Coitus cog7iatus. Until now the type of this species had remained 

 unique, no additional specimens having come into any museum or having been collected by any natur- 

 alist so far as we are informed. 



At Lake Bennett, July 19-21, 1903, 45 specimens were collected. They were obtained by the use of 

 the seine at various places along the shore, chiefly toward the head of the lake above the railroad station 

 and near the crossing of the Yukon and White Pass Railroad. These specimens range in length from 

 1.2 to 3i inches. Although the original description is very brief there is no doubt in our mind as to the 

 identification. Following is a detailed description: 



Head 3.66 to 4.1 in length; depth 5.13 to 6.2; eye 3.8 to 4.66 in head; snout 3.6 to 4; maxillary 

 2.25 to 2.5; mandible about 2; interorbital width 5.25 to 6; dorsal usually viii-17 (viii-15, v:ii-16, 

 ix-15, ix-17, and i.x-18 indicate the range of variation); longest dorsal spine about 3 in head; longest 

 dorsal ray 1.75 to 2; anal usually 11 or 12, varying from 10 to 13; longest anal ray about 1.75; pectoral 

 13 or 14, its longest rays (14 or 15) 3.87 to 4.2 in head, lowermost 7 or 8 rays thick, but not branched; 

 ventral i, 3, the length 5.5 to 6 in head; caudal lobes about 5. 



Body rather heavy forward, tapering gradually to the rather slender caudal peduncle; head moderate, 

 evenly rounded above, interorbital space narrow, slightly concave; mouth moderate, somewhat oblique, 

 maxillary reaching middle of pupil, lower jaw slightly included; branchiostegal rays 6; gill-membranes 

 separate, joined to the isthmus; villiform teeth on jaws and a small patch on the vomer; caudal peduncle 

 slender, its least width about 2 in its least depth; head entirely smooth; preopercle with a single spine 

 at the angle projecting backward and upward, chiefly concealed by skin; lower edge of preopercle with 

 one rather distinct Ijroad spine prrijecting downward and forward, in front of which is another poorly 

 defined spine or blunt point; opercle without spine; no other spines or filaments about head; body 

 entirely smooth except a patch of small roughish scales under the pectoral; fins well developed, spinous 

 and soft dorsal barely connected; caudal truncate or slightly rounded; pectoral broad at base, the tip 

 reaching past beginning of anal ; ventrals scarcely reaching vent ; vent usually somewhat nearer tip of 

 snout than base of caudal; there is, however, some slight variation in this character; in one specimen, 

 apparently a female, it is equally distant from tip of snout and base of caudal. 



A specimen 3J inches long was. in life, dark olive, much mottled; trace of about 6 dark saddles 

 less distinct than inmost specimens; first dorsal blackish olive with a narrow orange edge, the fin mesially 

 darker; second doi-sal dusky olive and translucent, the olive in irregular blotches; caudal with 4 or 5 

 vague bars of darker olive; ventrals and anal uncolored; pectoral brown with 4 narrow irregular dark 

 Ijars, the coloration more olive and more uniform than usual; a patch of light colored, rather coarse 

 prickles behind axil; belly silvery; lower jaw greenish, faintly barred with 5 black dots. •■' 



There are two patterns of coloration, probably representing the two sexes, a darker and a lighter 

 phase. The darker phase maybe described as follows: Sides and top of head, anterior portion of body, 

 the beginning of soft dorsal, and sides of body along base of soft dorsal and upper part of caudal peduncle, 

 dark or blackish, more or less vermicidated with lighter; base of caudal fin with a large Y-shaped black 

 area; tip of lower jaw dark; under side of head and entire lower parts of body yellowish white, profusely 

 covered with numerous minute black or brownish punctulations; spinous dorsal lilack, white at the 

 tip; soft dorsal vermiculated with dark and light, the distal half lighter; anal yellowish-white with fine 

 dark punctulations; caudal dirty white, with fine dark punctulations and evidence of faint darker 

 cross-bars; pectoral dark on l^asal two-thirds, lighter at the tip, with rather distinct vertical cross-bars 

 of dark and light; ventrals yellowish- white, somewhat punctate with dark. 



A specimen of the lighter phase may be described as follows: Head and upper parts of body 

 brownish white, blotched with darker; occipital region dark; back with about 6 dark or brownish saddles, 

 distributed as follows: The first, which is very small, at beginning of spinous dorsal, the second under 

 last dorsal spines, the third under third to sixth dorsal rays, the fourth under eighth to tenth dorsal rays, 

 the fifth under the last dorsal rays but one. and the sixth on base of caudal fin; the third and fifth 



