268 
Transactions Texas Academy of Science. 
White^ Charles A. 
futherance of these objects I traversed the western portion of the State 
along several extended lines and gathered important data there, especially 
concerning the relation of the Cretacegus formations, which are continuous 
with those of the .Rocky Mountain region to the northward, to those in 
eastern Texas, which are continuous with the Cretaceous formations of the 
other Grulf States to the eastward. During this reconnaissance various 
points along the valley of the Rio Crande were visited, and the formations 
which were especially under investigation were in some instances traced 
into the Republic of Mexico for the purpose of making the observations 
more complete. From these observations, in connection with others pre- 
viously made, general conclusions have been reached, of which the following 
is a brief statement. 
The Cretaceous series of Eastern Texas is separable into two principal divi- 
sions, an upper and a lower, each having distinct and well-marked Paleon- 
tological characteristics. A study of their fossil faunas respeotively has 
shown that while the formations of the upper division may be correlated, 
at least in a general way, with the Cretaceous formations of the great 
interior region, and also with those of the G-ulf States, the lower division 
cannot be so correlated; that is, the lower division belongs to a lower 
horizon than that of any other Cretaceous strata of North America at 
present known, except the older Cretaceous strata of the Pacific coast and 
perhaps those of the yet comparatively little known Rotoimac group of the 
Atlantic coast. Strata of the lower division of tbe Texas Cretaceous have 
not been recognized to the eastward of that State, nor farther northward 
tbain southeastern Kansas, but they extend to western Texas and over into 
Mexico, where they are overlaid by the representatives, of the Dakota, 
'Colorado, Fox Hills and Laramie groups, as they are overlaid by the for- 
mations of the upper division in eastern Texas.” Pp. 179-180. 
Correlation of the. upper division of the Texas series. Plan of work in 
Texas. Collections of fossils. 
428. ' 
'The Lower Cretaceous of the Southwest and its Eelation to the 
Underlykug and' 'Overlying Fobinatiions:. 
Amer. Jour, of Science, III, Yol. XXXYIII, pp. 440-445. 
Xew Haven, Dec., 1889. 
The Cretaceous strata of Texas referable to two divisions : Upper and 
Lower. Not necessarily equivalent to European section of the same name. 
The upper Missouri river section of Meek and Hayden, including the 
Dakota group, represents the Upper Division; the Comanche series the 
Lower. :Strata of the Lower Division not discovered east of the 65th 
meridian. 'With the probable exception of a locality in Central Kansas 
none have been found north of the southern part of Indian Territory and 
the southwest part of Arkansas. They exist in the extreme southern 
part of New Mexico. Fossils from near Arivechi, Sonora, indicate Lower 
Cretaceous. This is the most westerly locality. The Lower Cretaceous of 
California contains a different fauna, and is not referred to here. Other 
exposures in Mexico. Createst development of Lower Cretaceous strata in 
