780 



BULLETIN UNITED STATES GEOLOGICAL SUEVEY. 



Idalurus headlei Gill (1862), Proc. Boat. Soc. Nat. Hist. 43. 



letalurus headlei Jordan & Copeland (1876), Check List, 159. 

 1859— Pimelodus Jiouglm Girard, Proc. Acad. Nat. Sci. Pbila. 15'J. 

 18.59 — Pimelodus megalops Girard, Proc. Acad. Nat. Sci. Pbila. 161. 



letalurus megalops Jordan & Copeland (1876), Bull. Buff. Soc. Nat. Hist. 159. 

 1859 — Pimelodus graciosus Girard, Proc. Acad. Nat. Sci. Phila. 161. 

 1860 — Pimelodus hammondii Abbott, Proc. Acad. Nat. Sci. Phila. 568. 

 1860 — Pimelodus notatus Abbott, Proc. Acad. Nat. Sci. Phila. 569. 

 1862 — letalurus simpsoni Gill, Proc. Bost. Soc. Nat. Hist. 43; (1876), Ich. Capt. Simp- 

 son's Exp. 417. 



Heads of three specimens, not obviously different from Eastern speci- 

 mens of this widely diffused species. The specific names olivaceus, simp- 

 soni, hammondi, and notatus have been given to Channel Cats from the 

 Missouri region, chiefly on account of their " remote habitat"; but the 

 examination of specimens does not show a shade of difference. 



Family CATOSTOMIDiE. 



Genus PANTOSTEUS Cope. 

 3. — Pantosteus virescens Cope. 



1876—Pantosteus virescens Cope, Lieutenant Wheeler's Espl. W. 100 Mer. v, Zool. 675. 

 Pantosteus virescens Jordan &, Copeland, Check List Fishes N. A. 156, 1876. 

 Pantosteus virescens, Jordan, Bull. U. S. Geol. Suiv. Terr, iv, 416, 1878. 



Numerous small specimens, from two to seven inches in length, agree- 

 ing very well with Professor Cope's description. They all have the 

 peculiar form of mouth, and the semi-cartilaginous maxillary sheath, 

 which the other members of this genus and some of the species of 

 Catostomus possess. The head is very short, forming barely one-fifth 

 the length without caudal. The scales are very small, there being from 

 95 to 100 in the lateral line. All of these specimens have, however, a 

 small fontanelle, which probably becomes closed with age; otherwise 

 the species is to be referred to Catostomus. Its relations to Catostomus 

 discobolus Cope are very close. 



