268 The American Naturalist. {Mareb, 
In a report on the Cretaceous area north of the Colorado Mr. J. A. 
Taff shows the detail of stratigraphy in four sectional views which give a 
concise view of the variations in thickness and structure and the rela- 
tions of each division and formation to its associate divisions or forma- 
tions, from the Brazos river on the south to the Red river valley on the 
north. Some attention is given to the soils of this region, and consid- 
erable definite information concerning the artesian water supply. The 
stratigraphic work is largely based on the paleontological determina- 
tions of Prof. F. W. Cragin. : 
Prof. Cope recently described two new species of Plesiosauroids from 
the Pierre formation of the Upper Cretaceous of South Dakota, under 
the names Embaphias circulesus and Elasmosaurus intermedius. The 
first named represents a new genus allied to Pliosaurus, having a short 
neck and strongly biconcave vertebra. He also described the con- 
struction of the posterior part of the skull in another Plesiosauroid, 
the Cimoliasaurus snovii of Williston, showing that the supratemporal 
and supramastoid bones are both present and distinct. (Proceet 
Amer. Philosoph. Soc.). 
CexNozorc.—As to the origin of certain hydrocarbons of Utah, Mr. 
M. E. Jones considers the theory of an animal origin advocated by 
Newberry to be the only tenable one. The}deposits with one possible 
exception, are all either Eocene or Miocene, and their source, according 
to the author, being the overlying or adjacent bituminous beds. These 
remarks apply only to the deposits situated near the coal beds of Utah 
in the neighberhood of Pleasant Valley Junction. (Science Dec. 1893.) 
