THE WHITEFISHES OF NORTH AMERICA. 295 



reaching slightly beyond the vertical at front of the eye, broadly 

 ovate; preorbital narrow, its greatest width 5 times in its length and 

 3J in eye; width of supraorbital bone 2^ in its length. Distance from 

 snout to nape one-third distance from nape to front of dorsal ; front of 

 dorsal nearer tip of snout than base of caudal by a distance equal to 

 length of snout and eye. Adipose fin large. Scales small, adherent, 

 very regularly imbricated. Color probably very dark in life; in spirits, 

 fins all blackish, with a bluish tinge (Gilbert). Large, reaching a 

 length of 2 feet. 

 Dr. Bean says : 



This is the muksun of the Russians, a name transferred from a Siberian species of 

 similar appearance. The broad wkitefish reaches the weight of 30 pounds, ranking 

 next in size to the inconnu only. It is a food-fish of great excellence. Dall states 

 that it is abundant in both •winter and summer, spawning in September in the small 

 streams falling into the Yukon. 



The type of this species came from Fort Good Hope, British America. 

 Murdock reports it from the Meade and Kuahroo rivers, Alaska; Town- 

 send found it in the Kuwuk River, Dall and Turner in the Yukon ; 

 and it was recently obtained by Miss Elizabeth Taylor in Great Bear 

 Lake. All the Alaskan references to G. clupeiformis probably belong 

 to this species, or to G. richardsonii, if the latter be distinct from G. 

 Jcennicotti. 



4. Coregonus richardsonii Giinther. 

 Richardson's Whitefish. 



Coregonus richardsonii Giinther, Cat., vi, 185, 1866, exact locality unknown. 



Very similar to the common whitefish, also to the broad whitefish, 

 with which it may prove identical. Scales 10-72 to 80-12; B. 9 ; D. 13; 

 A. 13. Snout of moderate length, the lower jaw included; eye shorter 

 than snout; maxillary reaching anterior edge of eye, 4 in head; sup- 

 plemental bone short, broad, and semicircular; inaudible shorter than 

 least depth of tail. Pectoral longer than head without snout. 



This species was described in 1868, the type locality being unknown, 

 but it was somewhere iu British America. It is a species of doubtful 

 validity. Only the types are known. Dr. G. A. Boulenger has kindly 

 sent us the following note regarding the types of this species which are 

 in the British Museum : 



I have examined the types (dry) of Coregonus richardsonii. There are about 20 

 gillrakers on the lower part of the anterior arch, the longest half the diameter of 

 the eye. The maxillary extends to below anterior border of eye, and its length is 

 4 times in length of head, as stated by Giinther, therefore a little shorter than in 

 C. clupeiformis. Tongue with 4 series of teeth, as iu C. labradoricus. It seems to 

 agree best with C. nelsoni (description), but has fewer scales in lateral line. Iu 

 short, 1 can not identify C. richardsonii with any of the forms known to me. 



