156 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Coregonus laurettae, n. s. 



Among the fishes brought down from uortberu Alaska during the 

 summer of 1880 are 4 white fish taken at Point Barrow by the U. S. S. 

 Thomas Cor win, Capt. C. L. Hooper commanding, and one of the same 

 species obtained at Port Clarence, by the U. S. Sch. Yukon. The mu- 

 seum catalogue numbers of these specimens are : 



27G95. Point Barrow, 1880, (4 examples). 



27915. Port Clarence, 1880, (1 example). 



The species is allied to G. Artedi Le Sueur and to (C.) lucidus Eich- 

 ardson. It differs from C. Artedi in the following particulars: 



(1) The eye is } as long as the head (| in Artedi) ; 



(2) The length of the dorsal base corresponds with that of 16 oblique 

 smes of scales immediately under it (10 in Artedi) ; 



(3) The length of the mandible is contained 2^ times in that of the 

 head (2J times in Artedi) ', 



(4) The lateral line runs through 84 to 95 scales (not more than 77 in 

 Artedi) ; there are 10 scales in a transverse series from the origin of the 

 dorsal to the lateral line and as many from the origin of the ventral to 

 the lateral line ( 9-9 in Artedi) ; 



(5) The ventral has 12 rays (11 in Artedi). 



From C. lucidus it is separated by the following characters : 



(1) There are lingual teeth (none in lucidus) ; 



(2) The ventral appendages are less than one-half as long as the ven- 

 tral (more than one-half in lucidus) ; 



(3) The transverse rows of scales between the origins of dorsal and 

 ventral and the lateral line are 10-10 (10-8 in lucidus) ; 



(4) The lower jaw is contained 2-J times in length of head (2 J times in 

 lucidus according to Richardson's measurements) ; 



(5) Judging from the figure given by Richardson the number of rows 

 of scales under the dorsal base of my sijecies is 6 greater than in lucidus. 



DESCRIPTION. 



Br. IX— X; D. 11—12 divided rays; A. 10—11 divided rays; V. 12; 

 P. 16 ; L. lat. 84-95 ; length of types 12—16 inches. 



The height of the body is greater than the length of the head and 

 equals one-fourth of the total length without the caudal ; the distance 

 of the nape from the front margin of the jaw is contained 2J times in 

 its distance from the beginning of the dorsal. The diameter of the eye 

 equals the length of the snout and about \ that of the head. Maxillary 

 reaches nearly to the middle of the eye, its length contained 3^ times in 

 that of the head ; the supi)lemental bone is slightly more than half as 

 long as the maxilla and its greatest width equals ^ of its length. The 

 length of the mandible equals f of that of the head, reaching to the hind 

 margin of the orbit. The appendage of the ventral fin is less than half as 

 long as the fin and nearly equal in length to the 7 scales immediately 

 over it. 



