FISHES, LAHONTAN SYSTEM OF NEVADA AND NORTHEASTERN CALIFORNIA. 47 



Measurements op Catostomus tahoensis — Continued. 



EAGLE LAKE. CALIFORNIA. 



Length of body mm 



Length head 



Depth body 



Depth caudal peduncle 



IvCngth caudal pedxmcle 



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 



Pectoral rays 



Scales lateral line 



Scales above lateral line 



Scales below lateral line 



Scales before dorsal 



362 



32s 



276 



28s 



o. 24 



.215 



.09 



• I4S 

 .IIS 



■ 032 

 . II 



• 17 

 .19 

 .48 

 •55 

 •15 

 . 10 

 •15 

 .19 

 . 20 

 •13 



■ 20s 



II 

 7 

 >4 

 89 

 19 

 16 

 44 



e 



0-23S 

 . 205 

 .08s 

 .16 

 .IIS 

 .032 

 .105 



• 17 

 .205 

 •SO 

 •56 

 .14 



. xo 



.14 



• 17 



• iSs 

 ■ 13 



J 

 o. 25 



.20s 



.09s 



15 



12 

 035 



<? 



o. 24 



.2IS 



.08s 



•IS 



. 12 



•031 

 .IDS 



.i6s 

 . 20 

 •SI 

 •S6 

 ■ 14 

 •095 

 • IS 

 •19 

 .185 



o. 24 



. 219 

 .085 

 .165 



• IIS 



• 03S 

 .105 

 .i6s 

 .195 



• 49 

 •57 

 •14 

 .09 

 .16 

 . 20 

 .I8s 



• 14 



■ 205 



<? 



o. 24 



. 205 



.09 



•IS 



•IIS 



.032 



.105 



.i6s 



. 205 



• 485 

 •55 



• 14 



• 09s 



• 145 

 .19 

 •175 

 •13 

 .18s 



. 20s 

 .08s 



• IS 

 . 12 

 .032 



• los 

 .165 

 •I9S 

 •48s 

 .565 

 •155 

 . 10 

 •15 

 .195 

 .iS 



• 14 

 •195 



<? 

 o. 24 

 •195 

 .085 

 •14 

 . 12 

 •035 

 .105 

 • 17 

 •195 

 •SI 

 •575 

 .14 

 .09 

 .14 

 .195 

 .195 

 •14 

 . 20s 



235 



22 



095 



14 



IIS 



°32 



10 



i6s 



(? 



0.245 

 •215 



• 08s 

 .16 

 •IIS 

 ■ 03S 

 . 10 

 ■17 

 •215 



• 48s 



•57 



■IS 



. 10 



•145 



.I8s 



.18 



.14 



.19 



7 

 15 

 94 

 20 

 16 

 48 



Catostomus arenarius, new species. Sand-bar sucker. 



Examples of the species, which is here described for the first time, resemble those of C. tahoensis so 

 closely as to easily pass unnoticed among them. The scales of C. arenarius are larger, however. This 

 species is apparently a representative of C. macrocheilus , C. snyderi, and C. occidenialis , all similar coarse- 

 scaled forms of the Columbia, Klamath, and Sacramento River systems, respectively. It should not 

 be regarded as a very close ally of either C. catostomus, C. rimiculus, or C. microps. It differs but little 

 from C. warnerensis of the Oregon Lake system, and it is possible that the immediate relationships of 

 that form may be with this species rather than with C. catostomus or C. tahoensis. C. arenariics has 

 smaller scales than are found in C. macrocheilus, C. snyderi, or C. occidenialis. In addition to the smaller 

 scales it has fewer dorsal rays than are found in C. occidenialis or C. snyderi.a 



When its relationships are considered, the discovery of this species becomes a matter of considerable 

 interest, for it adds an important link to the chain of related catostomid species which are known to 

 occur in the Sacramento, Klamath, Columbia, and Lahontan systems. The following diagram will 

 serve to illustrate the probable affinities and distribution of these forms: 



Coarse-scaled catostomids . 



'Sacramento C. occidenialis. 



Klamath C. snyderi. 



Columbia C. macrocheilus. 



Oregon Lake C. warnerensis. 



.Lahontan C. arenaritts. 



Sacramento C. microps. 



Klamath C. rimiculus. 



Columbia C. catostomus, 



Lahontan C. tahoensis. 



It has been suggested that the lake region of eastern Oregon 6 may in the remote past have furnished 

 a free way for the migration of both a fine and a coarse scaled catostomid, which became differentiated 

 after entering the systems where its representatives are now found. But one species, C. warnerensis, 



1 Bulletin, United States Bureau Fisheries, vol. xxvn, 1907, p. 80-84, 161-169. 

 6 Bulletin, United States Bureau Fisheries, vol. xxvn. 1907, p. 77. 



Fine-scaled catostomids. 



