LITERATURE. 675 



found on a hurried run across this range % well denned specimen of Halysites 

 catenulatus in the rock. 



Dr. Shumard, as well as Prof. Hall, recognized the Carboniferous strata 

 which form also the cliffs of the Sierra Diabolo north of the Carrizo Moun- 

 tains, and probably also at least the flanking and capping of the mountain 

 range east of the Diabolo, running down from the Guadaloupe Mountains. 

 But though in the Eagle Mountains and north of El Paso on the Mexican 

 side of the river some coal (?) was found in small quantities, I join Prof. R. 

 T. Hill when he says. "The Trans-Pecos area belongs to the great deposit 

 of the non-coal bearing marine Carboniferous of the west."* 



William Kennedy's "Rise, Progress, and Prospects of the Republic of 

 Texas" refers half way reliably only to the east- rn portion of the State, and 

 the maps attached to this publication show plainly that Trans-Pecos Texas 

 was then entirely terra incognita. 



Ph. Dr. James P. Kimball, in the American Journal of Science and Arts, 

 November, 1869, Article xxxvii ("Notes on the Geology of Texas and Chi- 

 huahua"), expresses the opinion that the Limpia (Davis) Mountains are al- 

 together metamorphic, denying the igneous character. But traveling along 

 the old stage road from Fort Davis to El Paso in daytime the geologist can 

 not miss seeing granites, lava, and other igneous rocks, although meta- 

 morphic and stratified portions can clearly be seen besides the igneous rocks. 

 It seems Dr. Kimball, like other travelers through West Texas, took the 

 Davis, Van Horn, Carrizo, and Diabolo mountains as the same range. But 

 even if so, it is hard to comprehend how the presence of igneous rocks could 

 have been overlooked. 



Dr. Kimball, however, recognized that orographically the Limpia Moun- 

 tains form part of the great divide between the Pecos River and the Rio 

 Grande, and his supposition (in contradiction to Mr. Arthur Schott's opinion) 

 that the southern continuation of the Limpia Mountains in Mexico is not the 

 Sierra Ricca, but the Sierra Carmen, must be accepted as true. The contin- 

 uity can be traced down the Mount Ord range to the Sierra St. Jago, and the 

 ranges east of the last named mountains, the Rosillas, Chisos and Corazones, 

 to the Sierra Carmen. 

 » He calls the rock of the Limpia Canyon a porphyritic quartzite, supposing 

 it to be a metamorphic sandstone on account of its seeming stratification, but 

 even superficial examination shows it to be trap of Rhyolitic character. 



How far Dr. Kimball is correct in calling the underlaying arenaceous ma- 

 terial the "Cantera" of the Mexicans I can not decide, as I am not familiar 

 with this rock. 



*See also earlier statement of this fact by Prof. James Hall, United States and Mexican 

 Boundary Survey Report, p. 124. 



