434 GEOLOGICAL SURVEY OF THE TERRITORIES. 



With the Salmo virginalis, probably from near Fort Bridger, from the 

 head- waters of the Green River or Western Colorado. 



Catostomidce. 



I have proposed to adopt as valid (Proc. Amer. Philos. Soc, 1870, 

 480) seven genera of this family. I would now add an eighth, which 

 embraces species which combine "with the characters of Gatostomus 

 proper, a complete union of the parietal bones, which obliterates the 

 fontanelle so universal among the suckers. The only other exception is 

 seen in Cycleptus, Raf., as I have already mentioned. In all the members 

 of the family where I have examined it, this fontanelle is quite open and 

 of no doubtful proportions, and nowhere reduced to the slit often seen in 

 the Siluridce. In searching for the characters of Girard's so-called 

 genera Minomus and Acomus, I find that the type of the former, M. 

 insignis, B. G., presents the character above mentioned. I therefore 

 adopt his name for the new genus, and add two new species, M. delphi- 

 nus and M. bardus. Whether his two other species, M. plebeius and M. 

 clarkii, belong to it is uncertain as yet, but they have the same physi- 

 ognomy. 



CATOSTOMUS, (LES.) 



Several species of this genus were procured by Dr. Hayden. For 

 their fuller elucidation the following table, embracing also those of 

 Minomus, is appended. 



I. Scales of the posterior part of the body materially ~] 

 larger than those of the anterior. 



a Anterior dorsal ray nearly equidistant between end of 

 muzzle and base of caudal fin. J ^ ar i seunl 



Head five and a half times in length to end of caudal ; ' ' J 

 muzzle projecting, upper lip pendent, very short, with 

 two rows tubercles ; smooth margins narrow ; scales 

 1. tr. 28 5 eye ±-i head ; V. 10. 



As the last, but the lips much larger ; upper with three ) 

 rows tubercles, and both with wide smooth margin ; > C. discobolus. 

 eye, 5.5 in head, V. 9 ; isthmus wider. ) 



II. Scales of body subequal. ~) 

 a Origin dorsal nearer origin of caudal fin than end of ! 



muzzle. I M 7 7 / • 



Upper lip not pendent ; head one-fifth length to end of ( Mm aei l mmus ' 



caudal ; upper lip wide, D. 11, V. 10 ; scales tr. 1. 30 ; 



ventral fins small, 

 aa Origin of dorsal fin nearer end of muzzle than basis 7 



of caudal. 

 JEEead five and a half times in length vith caudal ; upper )■ 21 . bardus. 



lip wide, not pendent ; isthmus wide ; eye, one-fifth, 



head ; 1. tr. 30 ; D. 11, V. 10 ; a light band on side. J 



Gatostomus sucklii, Girard ; United States Pacific Railroad Report, 

 :X, p. 226, PL LL— Waters of the Platte. 



CATOSTo:\rus latiptnke, Baird and Girard ; Pr. A. N. Sci., Phil., 1853, 

 388; United States Mexican Boundary Survey, III, 39, PI. XXIV, 1-6. 

 (Aconms, Girard.) — Two heads from the Green River. 



Oatosto^ius geiseum, Girard ; Pr. A. X. Sci., Phil., 1856, 174; United 

 States Pacific Railroad, X, 222, PI. XLIX, figs. 5-9. — Two specimens 

 from Horse Creek, (waters of the Platte, August 27th,) one from Red 

 Cloud Creek, and three from other waters of the Platte. 



