44 



BULLETIN OF THE BUREAU OF FISHERIES. 



The dorsal fin was dark olive, pectorals and ventrals tinted with yellowish pink, lips yellowish white, 

 iris brassy. No difference could be found in specimens of this species from Eagle Lake and those from 

 the Lahontan system. 



In the rivers this species is very numerous. Where the water contains much silt they are light in 

 color, often very pale olive, with a considerable amount of light yellow. Late in the season the red 

 stripe seems to almost entirely disappear from the males and it is not seen at all in the females. The 

 young have several dusky spots on the sides. 



The affinities of this catostomid will be considered with those of the following species, C. arenarius. 



Measurements and scale counts are given here, numerous in this case because the Eagle Lake 

 specimens are included in the species. 



The measurements recorded in the following pages v^ere made by means of dividers 

 and a proportional scale. They are expressed in hundredths of the length of the body 

 (which is recorded in millimeters), measured from the tip of the snout to the end of the 

 last caudal vertebra. 



The length of the head is measured from the snout to the posterior edge of the opercle, the opercular 

 flap, which is apt to shrink, not being considered. Depth head, measured at occiput. Depth body, 

 the greatest depth. Snout to dorsal; snout to ventral, from tip of snout to anterior end of base of fin. 

 Depth caudal peduncle, at the narrowest place. Length of caudal peduncle, base of posterior anal ray 

 to end of last vertebra, not to base of lowermost caudal ray, as the latter point is often indefinite. Length 

 of snout, tip of snout to anterior border of eye. Interorbital width measured on skull, the dividers 

 being closed as nearly as possible between the eyes. Snout to occiput, tip of snout to point on occiput 

 where scales begin. Length base of dorsal or anal, distance between bases of first and last rays. Length 

 caudal, from end of last vertebra to tip of upper lobe. Scales lateral line, counted to end of last vertebra. 

 Scales above lateral line, from lateral line upward and forward to a point near middle of back. Scales 

 below lateral line, from anterior edge of base of anal upward and forward to lateral line; lateral line 

 series not included in either count. Scales before dorsal, the number of rows between base of first 

 dorsal ray and the occiput. Dorsal and anal rays, when the posterior ray is cleft to the base it is still 

 counted as one. The anterior ray is often spinelike and preceded by one or more closely adnate simple 

 rays. These are enumerated as one. 



