6o BULLETIN OF THE BUREAU OF FISHERIES. 



Siphateles obesus (Girard). Lake chub. (Species illustrated on p. 64.) 



This is the Rutilus or Myloleucus <^ olivacens of recent authors, which, at times confused with 

 Leucidius pectinifer, has been reported from various parts of the Lahontan system. It was first described 

 from the Humboldt River as Algansea obesaJ> The type of this species, no. 193, United States National 

 Museum, is a specimen measuring 171 millimeters, and although the pharyngeal bones have been 

 removed there seems to be no reason to doubt that it belongs to the same species which Cope later called 

 Leuctis olivaceusy and which is abundantly represented in the Humboldt River, its tributaries, and 

 other streams and lakes of this system. 



S. obestis is related to similar forms, S. columbiamis, S.formosu?, <^ S, bicolor, and S. oregonensis, of 

 the Columbia, Sacramento, Klamath, and Oregon Lake systems. Its affinities are most close to the 

 Oregon Lake form, S. oregonensis, and it is very doubtful whether the latter should be recognized at all. 

 The form called S. oregonensis is made up of isolated tmits which occupy distinct basins and which 



dorsal fin. The following measurements are in hundredths of the length to base of caudal fin, which is 130 millimeters. Head 

 0.2S; depth body 0.28; depth caudal peduncle o.ii; snout to occiput 0.22; snout to dorsal 0.54; snout to ventral 0.56. The 

 gillrakers are 11 in number, short and pointed. 



R. atrarius and Tigoma obesa Girard (Proceedings. Academy Natural Sciences Philadelphia, 1856, p. 206) are apparently not 

 synonymous. The type of the latter. United States National Museum, no. 215. is a specim.en with a very long deep body, small 

 head, and short roimded fins, looking much like a well-fed and fat example of R. baltealm, such as one occasionally finds in a 

 slough or pond where food is very abundant. Its describer says that it came from Salt Lake Valley. The iluseum register gives 

 no locality. The teeth, 5. 2-2, 4. have a narrow grinding surface. There are S rays in the dorsal, 9 in the anal; scales in the lateral 

 series 5s; between lateral line and back 13; between occiput and dorsal fin 28. Length from snout to base of caudal iii milli- 

 meters; length head 0.25; depth body 0.24; depth caudal peduncle o.ii; snout to occiput 0.19; snout to dorsal 0.59; snout to ven- 

 tral 0.55. There are 7 stubby, pointed gillrakers. If this specimen was collected in Salt Lake Basin, it apparently represents a 

 species not since found there. 



Richardsonius kumboldti (Girard) is another nominal form known from the type only (Proceedings, Academy Natural Sciences 

 Philadelphia, 1856, p. 206). It is said to have been collected by Bowman and Beckwith in the Humboldt River. The species 

 has not been seen there since. There is difficulty in distinguishing between the type specimen and examples of R. hydrophlox. 

 It has a somewhat larger head, deeper body, and deeper caudal peduncle than any specimen of R. hydropldox with which it has 

 been compared. It differs from examples of R. cgregius from the Humboldt in having 11 rays in the anal fin, a deeper body, larger 

 head, and larger eyes. There are 54 scales in the lateral series, 13 between the lateral line and back. 29 between occiput and dorsal 

 fin. The dorsal is inserted considerably behind a vertical through the ventrals. Both this specimen and the type of T. obesa 

 were collected in the course of one of the early surveys. Neither has had an attached label. Both look Uke over-fed examples 

 of the same species which might have Uved in a spring or pond, the bloated body and short, rounded fins being characteristic. 



a Fowler (Proceedings, Academy Natural Science, Philadelphia, 1913, p. 71) finds that the cotype of Myloleucus pidveruientus 

 Cope which is preserved in the collection of the Philadelphia Academy has 2 rows of pharyngeal teeth. No type or cotype of 

 the species is in the National iluseum. The specimen examined by Fowler is apparently a Richardsonius. The name Siphateles 

 (Cope. Proceedings, Academy Natural Science, Philadelphia. 18S3, p. 146) then becomes available for the lake and channel species 

 that have been referred to Rutilus and Myloleucus. Through the kindness of Mr. Fowler the writer was enabled to examine the 

 type of Siphateles vittatus Cope at the museimi of the Philadelphia Academy. It is a specimen belonging to the species that is 

 here called 5. obcsus. 



t Girard, Proceedings, Academy Natural Science, Philadelphia, 1856. p. 183. 



c On careful comparison, the type of Algansea for jnosa Girard from Merced River, Cal., and also a number of specimens from 

 Wolf Creek, north fork of Feather River, collected by Rutter and referred to Rutilus bicolor, are found to differ in no way from 

 examples taken in Pit River and Goose Lake, these in turn being like those described by Cope as Myloleucus thalassinus. Sipha' 

 teles {Ruitlus or Myloleucus) bicolor is confined to the Klamath Basin and should not be confused with the Sacramento form. The 

 latter will now be referred to as Siphateles fortnosus. A partial synonomy of these forms may serve to eliminate some of the con- 

 fusion regarding them: 



Siphateles formosus (Girard). — Sacramento-San Joaquin system, including Goose Lake and its tributaries. Algansea formosa 

 Girard, Proceedings, Academy Natural Sciences, Philadelphia, 1856, p. 183. Myloleucus thalassinus Qope, Proceedings, Academy 

 Natural Sciences. Philadelphia, 1883, p. 144. Rutilus symmetricus Jordan and Evermann, Bulletin 47, United States National 

 Museum, 1896, p. 245. Rutilus thalassinus Snyder, Bulletin, Bureau Fisheries, vol. xxvn, 1907, p. 86. Rutilus bicolor Rutter, 

 Bulletiu, Bureau Fisheries, vol. xxvn, 1907, p. 135. 



Siphateles bicolor (Girard).— Klamath River. Klamath Lake, and tributaries. Algansea bicolor Girard, Proceedings, Academy 

 Natural Sciences, Philadelphia, 1856. p. 1S3. M yloleucus parovanus Cope. Proceedings, Academy Natural Sciences. Philadelphia, 

 1883, p. 143- Rutilus bicolor Jordan and Evermann. Bulletin 47, United States National Museum, 1896, p. 244. Gilbert, Bulletin, 

 United States Fish Commission, vol. xvn, p. 8. figure. 



Siphateles oregonensis (Snyder). — Lake region of southeastern Oregon; generally distributed. (Not in Goose. Klamath, and 

 Malheiu- Basins.) Rutilus oregonensis Snyder, Bulletin, Bureau Fisheries, vol. xxvn, 1907, p. 87, fig. 3. Myloleucus formosus 

 Cope, (not of Girard), Proceedings. Academy Natural Sciences, Philadelphia, 1S83, p. 143. 



Siphateles columbianus (Snyder). — Columbia River, Malheur Lake Basin. (Not known from the Snake River or Bonneville 

 Basins.) Rutilus columbianus Snyder, Bulletin, Bureau Fisheries, vol. xxvn, 1907, p. 92, fig. 4. 



Siphateles obesus (Girard). — Lahontan system, including Eagle Lake. AlQanseaobesaGirard, Proceedings, Academy Natural 

 Sciences, Philadelphia, 1856, p. 183. Leucos obesus Jordan. Report Chief, Engineers, 187S, pt. 3, Appropriation, N. N., p. 1614, and 

 L. formosus, p. 1615. Leucus olivaceus Cope, Proceedings, Academy'Natural Sciences, Philadelphia, 1883, p. 145, also L. dimidiatus 

 Cope, p. 14s. and Siphateles vittatus Cope, p. 146. 



