DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



445 



greatest height over the pectorals, the contours then descending in almost straight lines to 

 the base of the tail. Tlie thickness of the body (6) is less than in C arctifrons, being con- 

 tained nearly 17 times in the standard length. 



The scales are thin, decidnous, smaller than in C. ((ret if tons. There are about 40 

 scales in the lateral line, which is sligiitly curved over tlie pectoi-al, and, as nearly as can 

 be determined in the denuded specimens before mc, about V2 rows above and lU below the 

 lateral line at the broadest part of the body. 



The length of the head (25) is one-fourth of the standard length and about ,'5 times 

 tlie diameter of the eye (9), or the distance from the snout to the upper eye (9). Tlie inter- 

 orbital space is wide (4), equal to the length of the snout, and diagonally crossed by a strong 

 ridge, a continuation of two ridges which form the upper boundary of the lower and the 

 lower boundary of the upper orbit. 



The length of the maxillary (11) is less than half, that of the mandible (13) more than 

 half, that of the head. The teeth are minute, in single rows, closely set in the jaws, some- 

 what stronger upon the blind side. A strong short spine above the snout, at the anterior 

 termination of the ridge at the lower margin of tlie upijer eye. Hence the specific name 

 unicornis. 



The dorsal fin begins at the side of the preorbital spine, its anterior rays being slightly 

 crowded over ujioii the blind side. It is composed of I'.i to 75 simple rays. Its greatest 

 height (13) is half the length of the head. 



The distance of the anal from the snout (33) Is one-third of the standard length. The 

 number of rays is 00; their longest (1.'5) equal in length to the longest dorsal rays. 



The caudal is pointed, triangular, subsessile; its length (22) twice that of the maxillary 

 (1 1 ) and two-thirds the distance from the snout to the anal (33). The pectorals are inserted 

 far below the lateral line. The pectoral of the colored side is twice as long (18) as the 

 diameter of the eye, that of the blind .^ide as long (13) as the longest dorsal lays. The for- 

 mer is composed of 10 rays, the latter of 4. 



The length of the ventrals (11) is half that of the caudal. They are asymmetrically 

 placed, asis described under the generic diagnosis. 



Radial formula: D. 73-75; A. CO; P. 4, right, 10, left; L. hit. 40. 



Color, ashy gray, with dark lateral line. Eyes black. 



Current niiuiber of specimeua . 

 Locality 



26, 003. 

 R70 and 871. 



Extreino leuetli 



Leni;th tonriiiin of iiutkile cdurlal rays.. 

 Body : 



Greatest height 



l^east height of tail 



Head: 



Greatest length -^ 



Distance from sncmt to uppei* e.ye . . . 



Bistanee from snoiil to lower eye. .. 



Width of interorbital area 



Lenjrth of snout 



l.enjitii of ni;ixillary 



LiHi^tliof Minuililili) 



DiaiufttT ol orbit, longitudinal 



Dorsal .'spiiinus) ; 



Distauif lr<tm snout 



C.ri-iitc-Bt heiiibt 



Anal; 



instance from snout 



Height at longest ray 



Caudal: Length of miildle rays 



Pectoral : 



Distance from sinmt 



Length 



Ventral: 



Distance front snout on colored aide. 



Length 



Dorsal 



Anal 



Pectoral 



Number of scales in lateral line 



Milli- 

 meteis. 



lOOths of 

 length. 



47 

 11 



25 

 9 

 5 

 4 



4 

 11 

 13 



9 



5 

 13 



33 

 13 



22 



28 

 18-13 



26 

 11 

 75-73 

 60 

 , 10 L. 

 40 



