HALECOMOEPHI. 57 



appear, which become oblong fossae. These continue until they become 

 naiTOwed again, anterior to the caudal senes. In the latter they are as well 

 developed as the neurapophysial pits and are much like them. 



Several species of this genus have been found in the Bridger forma- 

 tion in "Wyoming and Colorado, but it does not occur in the Wasatch. 

 While some of them were first reported by Marsh, who referred them to 

 Amia, they were first described by Leidy (Report U. S Geol. Surv. 4to 

 Tol, I., p. 184, Plate xxxviii). One generic and one subgeneric names 

 were used by Dr. Leidy in this connection, but without diagnoses. Among 

 the specimens at my disposal I have found but one genus, to which I gave 

 the name now used, with a characteristic diagnosis 



This genus is the earliest known representative of the order Haleco- 

 morpM, which consists at present of but two genera; the present one and 

 Amia. The latter first appears in America in the ? Eocene Amyzon 

 shales of Florissant in the South Park of Colorado, where two species have 

 been found; A. seutata Cope, and A. reticulata Cope.* Pappichthys first 

 occurs in the Bridger formation, and constitutes one of the faunal distinc- 

 tions between that epoch and the Wasatch, which immediately preceded it. 

 However, it occurs in the Wind River beds, mixed with Wasatch Mammals. 

 In Europe this genus is found at lower horizons than in America, having 

 "been discovered by Dr. Lemoinef near Reims, in the Suessonian conglomer- 

 ate, which answers partly to the lowest Wasatch and partly to the Upper 

 Laramie epochs. 



Pappichthys sclerops Cope. 



Annual Report U. S. Geol. Surv. Terrs., 1672 (1873), p. 635. 

 Plate III, fig. 1. 



Established on a ramus of the mandible of one, and other similar 

 specimens of other individuals. These indicate a large fish, equal in size to 

 the alligator gar of the Mississippi. The dentary bone is more compressed 

 and deeper than in P. plicatus. The longitudinal groove runs above the mid- 

 dle line, and the poition of the bone below it thins to an edge. The upper 

 portion is thickened, and the alveolar border is wide and bounded by an angle 



* Se« Bulletin of tbe U. S. Geol. Surv. Terrs , 1875, p. 1. 



t Kecherclics s. 1. Oiseaux Foss. Tert. Infer, des En v. Reims, 1378, p. 65. 



