66 PROCEEDINGS OF THE ACADEMY OF [Feb. 



SOME TYPE-SPECIMENS OF THE AMERICAN CYPRINOID FISHES OF THE 

 GENUS RUTILUS. 



BY HENRY W. FOWLER. 



While studying the cyprinoid fishes in the Acadeni}- of Natural 

 Sciences of Philadelphia recently, a number of detailed notes were 

 made on the variation found in the genus Rutilus. The material 

 embraces a number of typical specimens of the American species, 

 most of which have not been critically examined since they were 

 described. Owing to the imperfect nature of the incomplete and 

 unsatisfactory original descriptions, it is hoped that the present 

 contribution will be of value. Few, if any, of the species have been 

 figured, and certainly not from these specimens. 



In searching for sufficient characters to separate the American 

 from the European species generically, I have been unsuccessful. 

 Most of the former show no scaly axillary ventral flaps, though 

 a few exceptions were noted. All the Old World species have this 

 character very evident, as represented in the collection, the pointed 

 scale appearing quite conspicuous. Therefore, while Myloleucus 

 (or Leucos) may eventually be found subgenerically distinct, the 

 elevation of Siphateles to generic rank by CockerelU would seem 

 hardly warranted solely on scale characters. 



Rutilus olivaceus (Cope). Figs. 1-3. 



Leucus olivaceus Cope, Proc. Acad. Nat. Sci. Phila., 1883, p. 145. Pyramid 



Lake, Nevada. 

 Leucus dimidiatus Cope, I.e. Pyramid Lake. 

 Siphateles vitlatus Cope, I.e., p. 146. Pyramid Lake. 



Head 3| to 4; depth 3| to 5; D. iii, 7, i, rarely iii, 8, i; A, iii, 7, i, 

 rarely iii, 6, i or iii, 8, i or iii, 9, i; scales 50 to 62 in 1. 1. to caudal 

 base+3 or 4, usually 3, on latter; 13 to 15 scales above 1. 1., usually 

 14, frequently 13, seldom 15; 8 to 10 scales below 1. 1., usually 9, 

 frequently 8 or 10; 29 to 42 predorsal scales; snout 3| to 4i in head; 

 eye 3 to 5|; maxillary 3 to 4|; interorbital 2f to 3i; teeth 5 — 5, 

 frequently 5 — 4; length 2| to lOf inches. 



Nos. 19,354 (type) to 19,366, A. N. S. P., cotypes of Leucus oli- 

 vaceus Cope. 



1 Proc. Biol. Soc. Wash., XXII, 1909, p. 217. 



