472 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



eludes the first row and a half of scales above the lateral line, and 

 covers eight oblique rows (six in paratype) ; this spot is ocellated 

 by a wide lighter band, which is immediately preceded and followed 

 by rather indistinct saddles, similar to those of related species. 

 After an interspace three-fourths as long as the head, the dark spot 

 is followed by the usual dark saddle, which in this species is quite 

 indistinct. The head is lightly colored, with silvery reflections as 

 on the sides of the body; the opercle is dusky; the margin of the 

 branchiostegal membranes laterally is whitish. The buccal cavity 

 and the upper two-thirds of the branchial cavity are lined with a 

 dusky membrane; the parietal peritoneum is light purplish brown, 

 blotched with darker and underlain with silvery. The first dorsal 

 is mostly dark, but lighter near its base, and near the tip of the 

 spine; the second dorsal is light; the anal fin has a dark margin, 

 which is widest anteriorly. The pectoral fin is almost whitish, ex- 

 cept on its upper margin ; the ventral is dusky, with a blackish base. 



This interesting species is similar to the last one described, C . 

 triocellatws, but differs notably in lacking the ventral fossa, in its 

 plainer coloration, etc. It is also closely related to the next species, 

 C. argu-s, from which it differs in the produced dorsal spine, in the 

 broader snout with more convex sides, and in details in the squama- 

 tion of the head. From both of these species, C. dor sails differs 

 also in its finer scales, there being 6^ instead of 5| scales in a row 

 between the origin of the second dorsal and the lateral line series. 



Measurements of type in hundredths of length to amis. — Length 

 of head, 76 ; length of orbit, 21 ; postorbital length of head, 24 ; width 

 of interorbital, 17; width of suborbital, 9; distance from orbit to 

 preopercular margin at angle, 28; length of snout, 32; length of 

 upper jaw, 18; length of barbel, 3.7; depth of body, 39; width of 

 body, 26 ; distance from center of anus to origin of anal, 9 ; distance 

 from anus to base of outer ventral ray, 18.5 ; distance from base of 

 outer ventral ray to isthmus, 22 ; height of second dorsal spine, 84 ; 

 height of third dorsal ray, 51 ; length of first dorsal base, 16 ; length 

 of interspace between dorsals, 20.5 ; length of pectoral fin, 40 ; length 

 of outer ventral ray, 39 ; length of second ventral ray, 25. 



{dorsalis in reference to high dorsal fin.) 



30. COELORHYNCHUS ARGUS Weber. 



Coelorhynchus argus Weber, Fische der Sft&o^a-Expedition, 1913, p. 161, 

 pi. 4, fig. 4 and 4«. 



We hesitate to refer our specimens to ('. argus, as certain discrep- 

 ancies between them and Weber's description are difficult to explain. 

 The orbit is never quite as long as the postorbital length of the head, 

 as we measure these parts, either in our specimens or in Weber's 

 figure, but his measurements indicate the reverse. The interorbital 



