SALMON INVESTIGATIONS IN THE COLUMBIA RIVER BASIN IN 1896. 71 
hump ; mouth large, inclined upward at an angle of 45°, maxillary not nearly reaching vertical at front 
of anterior nostril; width of mouth If in snout, or 4 in head; upper lip thin, without papilla;; lower 
lip thin, entirely without papilhe, interrupted at symphysis, forming rather broad lateral lobes; pores 
on head very conspicuous; gillrakers larger than in C. stomias, broadly triangular at tip when viewed 
from behind, densely tufted on anterioredge, each appendage more or less bifid and club shaped, closely 
resembling those of C. liorus; fontanelle narrow, its length in snout, width one-fifth its length. 
Fins all small ; origin of dorsal a little nearer snout than base of caudal, its sixth ray over base of 
ventrals, free edge straight, base 2-f in head, last ray a little less than 2 in first, which is 2 in head; 
pectorals somewhat falcate, reaching slightly more than half distance to ventrals, their length If in 
head; ventrals very short, reaching only two-thirds distance to vent, free end nearly straight; outer 
ray longest, 2f in head ; inner shortest, 3f in head ; anal fin short, bluntly pointed, not reaching base of 
caudal, third and fourth rays longest, If in head; no tubercles on anal rays; caudal lobes equal, length 
about 1|- times the middle ray. Scales small and crowded anteriorly, about 14 rows downward and 
backward from front of dorsal to lateral line, 11 vertically upward from base of ventral to lateral 
line, about 38 oblique series before dorsal; lateral line nearly straight, with about 80 scales. Entire 
upper parts of head and body, and sides nearly to level of base of pectorals, dark olivaceous ; under parts 
abruptly whitish or yellowish in alcohol; a dark spot in upper part of axil; dorsal and caudal dark; 
pectorals dark on inner surface; ventrals and anal plain. 
From Chasmistes stomias this species is readily distinguished by its larger head, larger, more 
oblique mouth, less prominent snout, and very small fins. The differences in the fins are very great, 
particularly in the ventrals, as may be seen in the accompanying illustrations. It differs from C. 
brevirostris, as characterized by Dr. Gilbert, in its much larger, more oblique mouth, the absence of 
papilhe on the lips, and shorter fins. 
We name this species for the late Prof. Edward Drinker Cope, who wrote the first paper on the 
fishes of Upper Klamath Lake. 
Six nominal species of suckers have thus far been described from the Klamath Lakes, viz : Chas- 
mistes luxatus and Chasmistes brevirostris by Cope in 1879; Catostomus rex by Rosa Smith Eigenmann in 
1891; Catostomus snyderi and Chasmistes stomias by Gilbert, and Chasmistes copei by Evermann & 
Meek, the last three in the present Bulletin. Mr. A. Seale has recently taken C. luxatus as the type 
of his new genus Deltistes, which he bases upon the peculiar structure of the gillrakers. Dr. Gilbert 
finds that Catostomus rex is a synonym of Deltistes luxatus. As now understood, we therefore know 
from Upper Klamath Lake one species of Catostomus, one of Deltistes, and three of Chasmistes. 
9. Mylocheilus caurinus (Richardson). Columbia Chub. 
Obtained from Little White Salmon River, Lakes Washington and Sammamish at Seattle, and 
Lake Pend d’Oreille at Hope, Idaho. Abundant early in September in lagoon at mouth of Little White 
Salmon River, and seen in considerable numbers at steamboat landings between Portland and The 
Dalles. It does not occur in the Redfish Lakes in Idaho, nor has it been recorded from Wallowa 
Lake, nor from any of the streams or lakes south of the mouth of the Columbia. 
