GENUS PANTOSTEUS. 181 



diatc between that of Catostomus proper and that of the subgenus 

 Decadactylus. 



The genus was first indicated by Professor Cope in 1874, under the 

 name oi Minomus, he supposing at the time that Catostomus insi(/nis, the 

 tvpe of Girard's Minomus, was a species with closed fontanclle. On 

 obtaining specimens of G. insigniti, it became evident that such was not 

 the case, and the new name Pantosteiis was proposed for the genus. 

 Puntontcus runs very close to Catostomus. two species referred to the 

 latter genus {C. discobolus and C. arcvopus) being almost intermediate. 



Generic Cliaraclerizations. 



MiNOMUS Cope, 1872.— "I Lave proposed to adopt as valid (Pioc. Amer. Pliilos. Soc. 

 1870,480) seven genera of this family. I -will now add an eighth, which embraces 

 species which combine with the characters of Catostomus proper, a complete union 

 of the parietal bones, which obliterates the foutanello so universal among the 

 suckers. The only other exception is seen in C'^c?(2><«s, Raf., as I have already men- 

 tioned. In all the members of the family where I have examined it, this fontaueile is 

 ([uite open and of no doubtful proportions, and nowhere reduced to the slit so often 

 seen in Siluridce. In searching for the characters of Girard's so-called genera Minomus 

 and Acovius, 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. delphinus and M. hardus. Whether his two other species, M. plebcius and M. 

 clarJcU, belong to it is uncertain as yet, but they have the same physiognomy."— (Cope, 

 Hayden's Geol. Surv. Wyoming for 1870, p. 434, 1872.) 



Pantosteus (Cope) Yarrow, 1876.—" Professor Cope, in 1870, purposed to adopt as 

 valid seven genera pf this family; but in 1872, he stated bis belief that an eighth 

 should be added, which should embrace species combining the characters of Catostomus 

 proper, a complete union of the parietal bones, which obliterates the fontaueile, so uni- 

 versal among the suckers ; the only other exception being seen in Cycleptus, Raf., as he has 

 already observed. In all the members of the family that he has examined in this re- 

 gard the fontaueile has been found quite open and of no doubtful proportions, and is 

 nowhere reduced to the slit often seen in the Siluridse, unless it be in the Catostomus 

 discobolus. In searching for the characters of Girard's so-called genera Minomus 

 and Aconms, he expressed the view that the type of the former, ilf. insignis, Bind &, 

 Girard, presents the character in question. This conclusion was based on a specimen 

 sent to the Academy of Natural Sciences from Washington, bearing that name. Hav- 

 ing since examined live specimens of the M. i?;si^nfs, obtained by the geologists of this 

 suivey, he iinds them to be true Catostomi as determined by the presence of the fon- 

 taueile. It therefore requires a name, and he proposes for it that of Pantosteus. It 

 embraces P. platyrhynchus, P.jarrorii and P. virescens Cope of the present essay and P. 

 delphinus and P. tardus, Cope, Hayden's Report, /.c."—( Yamkow, iic«<. Wheeler's Expl. 

 W. WOliv Mer. vol. 5, p. fi7.3, 1870.) 



Pantosteus Cope «S: Jordan, 1877, — "Body oblong or elongate, with a short, sub- 

 quadrate dorsal liu ; air bladder in two parts ; lateral line well dev(;]oped ; fontanclle 

 obliterated by the union of the parietal bones." — (Johdan, Proc. Ac. Xat. Sc. Phila. 

 1877, p. 81.) 



