106 Cincinnati Society of Natural History. 
a lacustrine formation of Eocene age, though having examined an out- 
crop for forty miles, he discovered no fossil remains except fossil wood. 
He said the material is so easily transported that the drainage chan- 
nels are cut to a great depth, and the Puerco river becomes the recep- 
tacle of great quantities of slimy-looking mud. Its unctious appear- 
ance resembles, strongly, soft soap, hence the name Puerco, greasy. 
These soft marls cover a belt some miles in width, and continue at 
the. foot of another line of sandstone bluffs, which bound the immediate 
valley of the Puerco to a point eighteen miles below Nacimiento. 
This section of the Eocene strata in the region west of the Sierra 
Madre Range in New Mexico consists of green and black marls, which 
he named the Puerco Group, 500 feet; sandstone of the Wasatch Group 
1,000 feet, and red and gray marls of the same group, 1,500 feet; mak- 
ing a total thickness of 3,000 feet. 
He described,* from the Eocene of New Mexico, Ambloctonus sin- 
osus, Prototomus secundarius, P. multicuspis, P. strenuus, Diacodon 
alticuspis, D. celatus, Pelycodus frugivorus, Pantolestes chacensis, 
Opisthotomus astutus, O. flagrans, Antiacodon mentalis, A. crassus, 
Hyrachyus singularis, Hyracotherium:tapirinum, H. angustidens, H, 
cuspidatum, Bathmodon ilatidens, B. cuspidatus, Diplocynodus 
sphenops, Crocodilus grypus, C. wheeleri, and Dermatemys (?) 
costilatus. 
He described,t+ from the Miocene of Cumberland county, New Jersey, 
Phasganodus gentryi, Sphyrenodus silovianus, and Agabelus porca- 
tus ; from Flower’s marl pit, Duplin county, North Carolina,{ Pristis 
attenuatus ; from Edgerton’s plantation, in Wayne county, Pnewma- 
tosteus nahunticus; trom Halifax county, Mesoteras kerrianus, and 
Delphinapterus orcinus. From the Loup Fork Group of New * 
Mexico,§ Pliauchenia humphreysana, P. vulcanorum, Hippotheri- 
um calamarium, and Aphelops jenezanus ; and from the Pliocene of 
the West, Canis ursinus. 
Prof O. C. Marsh] described, from the Eocene of Wyoming, Lemu- 
ravus distans, Tillotherium fodiens ; from Utah, Diceratherium ad- 
venum, Diplacodon elatus, Orohippus uintensis, and Agriocherus 
pumilus, From the Miocene bad lands of Nebraska, Laopithecus ro- 
bustus, Anisacodon montanus ; from the John Day river in Oregon, 
* Geo. Sur. W. 100th Meridian, Syst. Catal. of Vertebrata. 
+ Proc. Am. Phil. Sci., vol. xiv. 
t Geo. of N. Carolina. 
2 Proc. Acad. Nat. Sci. 
| Am. Jour. Sei. and Arts, 3d ser., vol. ix. 
