vaughan.] LITERATURE. 7l 
Reference is several times made in the text to the Rio Grande 
region. PI. XXXVIII shows the areal distribution of the Lafayette 
and Columbian formations of southeastern United States, and repre- 
sents the upland gravel of the Rio Grande region as Lafayette. 
1892. Dumble (E. T.). See Second Rept. of Progress Texas Geol. Survey, pp. 7-19. 
Contains some general notes. 
1892. Comstock (Theo. B.). See Second Rept. of Progress Texas Geol. Survey, 
pp. 43-54. 
Contains notes on the region. 
1892. Taff (J. A.). See Second Rept. of Progress Texas Geol. Survey, pp. 70-77. 
1893. Hill (R. T.). The Cretaceous formations of Mexico and their relations to 
North American geographic development: Am. Jour. Sci., 3d series, Vol. XL'V. 
u Opposite Del Rio, Texas, the Exogyra arietina zone of the Deni- 
son beds of the Washita division extends far into Mexico." Pages 
320 to 323 give a discussion of the relations existing between the Upper 
Cretaceous and the Eocene deposits in the Texas-Mexico region from 
Eagle Pass to Laredo, and the areal distribution of the formations. 
On page 321 is the following statement: "The Montana-Laramie 
Eocene portion of the formation occupies the vast synclinal basin of 
the Rio Grande, east of the great bend, which I have termed the Rio 
Grande embay ment, outcropping beneath the detrital deposits of late 
Tertiary and Pleistocene age." 
Two maps accompany this paper. The first, fig. 2, gives the distri- 
bution of known Cretaceous outcrops in Mexico and adjoining portions 
of Texas. The second is a u Geologic outline of northern Mexico, 
showing relations of Atlantic Coastal Plain, Cordilleran and Great 
Plains region." The topography of this map is modified from the 
map of the Mexican International Railway. It shows the vast distri- 
bution of the Tertiary gravel. 
1894. Hill (R. T.) . Geology of parts of Texas, Indian Territory, and Arkansas 
adjacent to Red River: Bull. Geol. Soc. America, Vol. V, March, 1894, pp. 
297-338. 
On Plate XII a columnar section of the Cretaceous at Del Rio is 
given". The presence of Caprina limestone, Fort Worth limestone, 
and Exogyra arietina clays is represented. 
1894. Harris (G. D.). Tertiary geology of southern Arkansas; Ann. Rept. Geol. 
Survey Arkansas, 1892, Vol. II. 
Page 34 contains notes on Eocene fossils along the Rio Grande. 
1894. Dumble (E. T.). The Cenozoic deposits of Texas: Jour, of Geology, Vol. II, 
pp. 549-567. 
On page 550 the occurrence of Midwayan Eocene fossils on the Rio 
Grande, near the Webb-Maverick county line, is mentioned. Pages 
560 to 562 are devoted to a description of the Reynosa division, which 
