PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 659 



received from Mr. Willetts vary in length from 5J to 6J inches. Three of 

 these examples have the air bladder much distended and filling the 

 greater portion of the abdominal cavity. 



The specimen received from Professor Smith, which we take as the ba- 

 sis of our description, is 10 inches long. 



The species is most closely related to C. artedi, but differs from it and 

 from all other species known to me in many im]iortant characters which 

 have been only vaguely indicated in most of the published descriptions. 

 It is much more widely separated from C. artedi than is the var. sisco of 

 Jordan. 



Description.— Body elongate, moderately compressed, slender. 

 Head less compressed than body, its greatest width equaling one-half 

 the distance froai tip of lower jaw to nape; the lower jaw projecting con- 

 siderably even when the mouth is closed. Mouth large, the maxillary 

 reaching to the vertical through the anterior margin of the pupil. Pre- 

 orbital bone long and slender, more than one-third as long as the head. 

 Supraorbital as long as the eye, four times as long as broad. 



The greatest height of the body is considerably less than the length 

 of the head, and is contained five times in the total length without cau- 

 dal. The greatest width of the body is less than one- half its greatest 

 height. The least height of caudal peduncle equals the length of the 

 orbit and about one-third of the greatest height of the body. Scales 

 small, nine in an oblique series from the dorsal origin to the lateral line, 

 eighty-two tube-bearing scales, and eight in an oblique series from the 

 ventral origin to the lateral line. 



The length of the head is one-fourth of the total length to the end of 

 the lateral line. The distance of the nape from the tip of the snout is 

 nearly one-third of the distance from the tip of the snout to the origin 

 of tbe first dorsal. The length of the maxilla is one-third of the length 

 of the head. The mandible is one-half as long as the head. Lingual 

 teeth present. The eye is as long as the snout and one-fourth as long 

 as the head. Gill rakers long and slender, the longest five-sixths as long- 

 as the eye; there are fifty-five on the first arch, thirty-five of which are 

 below the angle. The insertion of the dorsal is nearer the tip of the 

 snout than the end of the middle caudal rays. The longest ray of the 

 dorsal equals the greatest length of the ventral and is contained seven 

 times in the total length to the end of the middle caudal rays (six and 

 two-third times in length to end of lateral line). 



The length of the pectoral is one-sixth of the standard body length. 



The insertion of the ventral is midway between the tip of the snout 

 and the end of the middle caudal rays. When the ventral is extended 

 the distance of its tip from the vent is only one-fourth of the length of 

 the fin. In this respect this species differs widely from C. artedi. 



Colors. — Back grayish silvery; sides silvery; dorsal and caudal with 

 darker tips. 



Radial formula.— D. iii, 9; A. ii, 13; Y. i, 12; P. i, 16; scales 9—82—8. 



