452 FOWLER— DESCRIPTION OF COREGONUS NELSONII. [Dec. 16, 



Gill-opening large, extending forward a little over half way in 

 length of head but not to posterior margin of eye. Rakers 6 -j- 14, 

 short, pointed, about 3^ in longest filaments. Filaments long, 

 longest 5 in head. No pseudobranchiae. Branchiostegals 8, rather 

 large and conspicuous, and graduated to uppermost which is largest. 

 Isthmus rather long, triangular and with convex surface. 



Scales small, cycloid, well exposed and more or less of equal size 

 except on base of caudal and on breast. None on chest. Distri- 

 buted in longitudinal even series. A pointed scaly flap in axil of 

 ventral. Head and fins naked, except base of caudal. Lateral line 

 continuous, more or less parallel with lower profile most of its 

 course and extending posteriorly along middle of side of caudal 

 peduncle to base of caudal. Tubes simple. 



Origin of dorsal nearer that of adipose fin than tip of snout or a 

 little behind tip of pectoral, high, and second branched ray longest. 

 Adipose fin well developed, beginning a little behind that of anal, 

 and length of fin a trifle less than half length of head. Height of 

 adipose fin nearly half of its base. Anal originating much nearer 

 base of caudal than origin of ventral, lower than dorsal, and first 

 branched ray highest. Caudal robust, deeply emarginate, and 

 lobes pointed. Pectoral rather long, about equal to height of 

 dorsal, and reaching a little over half way to ventral. Ventral 

 inserted behind origin of dorsal, a little longer than first branched 

 anal ray, and reaching half way to origin of anal. Vent close in 

 front of anal. 



Color in alcohol more or less faded uniform brown, lower side 

 and under surface paler. Fins brownish and immaculate. Each 

 longitudinal series of scales on trunk with median portion paler so 

 that body has appearance of many alternate dark and light longi- 

 tudinal bands, most distinct or pronounced above. Iris slaty. 

 Length about 24 inches. 



No. 7258, Wistar Inst. Anat. Phila. Meade River, Alaska. Nov. 

 1897. E. L. Macllhenny. This is an adult female. Also three 

 others which show the following : Head 5 to 5^ ; depth 3! to 4^ ; 

 D. Ill, 10 or III, II ; A. iii, 9 or iii, 11 ; scales 80 or 81 in lateral 

 line to base of caudal and 4 to 6 more continued out on latter ; gill- 

 rakers about 12 on lower half of first arch and 7 to 9 on upper half; 

 total length 21 to 24 inches. The smallest was obtained at Point 

 Barrow, Alaska. 



The following notes relative to the alimentary canal are expli- 



