SALMON INVESTIGATIONS IN COLUMBIA RIVER BASIN IN 1896. 69 
ventrals short, rounded, the middle rays hut little longer than the others; anal small, somewhat 
pointed ; margin of dorsal slightly concave ; caudal lunate, not deeply forked. Muciferous canals on 
head not strongly developed. Scales moderately large; lateral line nearly straight, not running 
upward toward nape. 
Length of type, 8 inches to base of caudal. 
The cotypes agree closely with the type in all characters of importance. 
We have compared our specimens of this species with specimens of C. occidentalis (Fig. 2) from 
the Sacramento River and find important differences. Comparing examples of the same size, we find 
that C. tsiltcoosensis has a smaller head, longer, more pointed snout, smaller eye, larger scales, and 
much smaller fins; the pectorals in C. occidental is are falcate while in this species they are more 
rounded, and the ventrals also are less pointed. 
An example of C. occidentalis 9 inches long has the head 4f; depth 5 ; eye5f-; snout 21 ; D. 12; A. 7; 
scales 13-70-10, 41 before the dorsal. 
This species is abundant in Tsiltcoos Lake and Siuslaw River. The specimens from Siuslaw 
River were obtained in brackish water. 
5. Catostomus macrocheilus Girard. Columbia Hirer Sucker; “Yellow Sucker.” 
Abundant throughout entire Columbia River basin ; obtained this year from Alturas and Wallowa 
lakes, in both of which it is abundant. It seems not to occur in Siuslaw River, nor in lakes of that part 
of Oregon. Five specimens from Lake Union near Seattle, and one from Lake Washington at Seattle. 
6. Catostomus snyderi Gilbert. 
One obtained from an Indian at the mouth of Williamson River, November 5. This species was 
caught, along with Chasmistes copei and Chasmistes stomias, in the small trap or basket nets which the 
Indians were using at that place. Three small specimens, 2f to 4f inches long, were taken in the 
seine at the south end of Upper Klamath Lake November 10, and two others, 2 and 2£ inches long, 
respectively, in a slough at Pelican Bay November 3. No large examples seen in shallow water. 
