FISHES, LAHONTAN SYSTEM OF NEVADA AND NORTHEASTERN CALIFORNIA. 49 



Measurements of Eight Specimens op Catostomus arenarius. 



IfCngtb of body mm 



Length head 



Depth body 



Depth caudal peduncle 



Length caudal peduncle 



Length snout 



Diameter eye 



Interorbital width 



Depth head 



Snout to occiput 



Snout to dorsal 



Snout to ventral 



Length base of dorsal 



Length base of anal 



Height dorsal 



Height anal 



Length pectoral 



Length ventral 



Length caudal 



Dorsal rays 



Anal rays 



Scales lateral line 



Scales above lateral line 



Scales below lateral line 



Scales before dorsal 



No. a 



.09 



.165 



. 12 



.035 



. 10 



.17 



.21 



•51S 



.565 



.14 



.09 



•IS 



.21 



.20 



•I4S 



•23 



0.26 

 .21 

 .08 

 ■ISS 



■ 13 



■ 03 



■US 

 ■I7S 

 .205 

 •SO 

 .58 



■ 13 



■ 08s 

 ■13 



■ i6s 

 .19 

 ■13 

 .19 



0.23S 

 .19 



.08 

 .16 

 •IIS 



• 045 

 .085 

 •IS 



• 21 



■SO 

 •S6 

 •IS 



• 095 



• 16 



•17 

 • 225 



0^245 



• 21 

 •09 



• 165 



• II 



• 045 



• 09 



• 16 

 .21 

 .51 



• S6s 

 .125 

 .08 

 •ISS 

 .19 

 .18 

 .14 



0.24 

 .20 

 .08 

 .155 

 •IIS 

 ■04s 

 . 10 

 .16 



■ ss 



•57 



.14 



.08 



.165 



.19 



.16 

 ■23 



23s 



225 



09 



17 



II 



04 



o9S 



IS 



I9S 



SO 



S8 



13 



08 



7 

 74 

 i6 

 13 

 39 



g 



° No. 1-3. Pyramid Lake; 4, Tnickee River near Pyramid Lake; 5. Fallen Leaf Creek near Lake Tahoe; 6. Humboldt River, 

 Carlin; 7, Pine Creek near Palisade; 8, Star Creek near Deeth. 



Pantosteus lahontan Rutter. Lahontan sucker. 



The relationships of the Lahontan sucker were thought by its describer to be with Pav tosteus generosus 

 of the Bonneville system. o An examination of the types of the suckers described from the Bonneville 

 Basin, and which have been lately regarded as synonymous with P. generosus, reveals the presence of 

 two species which appear to be generically different, Notolepidomyzon generosus (Girard) and Pantosteus 

 plaiyrhynchtts (Cope). The affinities of P. lahontan are with the latter. It has an open fontanel and 

 a long slender form like that of P. platyrhynchus. A series of carefully prepared specimens of P. 

 platyrhynchus is not available for a more detailed comparison of the species. 



The cutting edges of the mouth are provided with sharp, homy coverings. The lips are pendulous 

 and have many prominent papillae. The posterior lip is not deeply cleft, the papillose area opposite 

 the notch extending forward toward the center. The pectorals are pointed and somewhat falcate. 

 The anal frequently extends to the base of the caudal. 



In life, examples of this species are usually brownish olive above, of a lighter or darker shade, depend- 

 ing much on the surroimdings, and lighter to whitish beneath. Often a pale-red lateral stripe appears 

 after death in alcohol. Several males were observed with a bright-red lateral stripe, about equal in 

 width to the eye, extending along the side from middle of head to caudal fin, the color becoming brighter 

 in the region between the head and dorsal fin. The body was light olive above with brassy reflections, 

 lighter on the sides, merging into silvery and then into dead white below. The fins were brassy, the 

 axils of pectorals and ventrals orange red. Anal fin and lower half of caudal with dead white tubercles. 

 Peritoneum dense black. 



The alimentary canal is very slender, extremely long, and regularly coiled over the ventral surface 

 of the abdomen. The air bladder extends over about three-fourths of the length of the abdominal 

 cavity. Its anterior chamber is somewhat less than one-third as long as the posterior part. 



Females with nearly ripe eggs were observed in Long Valley Creek, July 13. Ripe eggs were found 

 in examples in Carson River, July 20, and in Quinn River, July 30. Both males and females appeared 

 to be migrating up the Humboldt River early in July, for they were congregating in large number below 

 obstructions. 



a Bulletin, United States Fish Commission, vol. xxn, 1902, p. 146. 



