LITERATURE. 673 



crops of granite between the end of the Guadaloupe and the Wichita moun- 

 tains, or a very perceptible modification of the Llano (Estacado)." 



I abstain from making numerous quotations from "Chapter II, Geology 

 of the Mountain Ranges," since the conclusions in this chapter seem to be 

 based mostly on specimens, which leave reasonable doubts as to determination 

 of location and character. We read for instance, page 13, "it is not impos- 

 sible that these dark gray blocks (mentioned in Capt. Marcy's Report, 1849), 

 although resembling sandstone, were the compact and fine-grained granite 

 just described, or possibly Carboniferous limestone." 



With the exception of hurried reconnoitering for water, I have not yet had 

 the opportunity to exte> d my observations to the Hueco Mountains, and I 

 shall therefore neither confirm nor contradict Mr. Blake's supposition that 

 the Hueco Mountains are principally granite and metamorphic, and that 

 stratified rocks occur on the flanks only. To decide whether these are Car- 

 boniferous strata or not is of course impossible without having specimens at 

 hand ; but I am inclined to believe that the stratified rocks flanking and cap- 

 ping the range are Carboniferous, since 1 found fragments of Carboniferous 

 fossils (encrynites and productus) in the southern extension of the Hueco Moun- 

 tains. 



Mr. Blake mentions also the Cornudos, evidently from hearsay, quoting 

 Mr. Bartlett: "This wonderful mountain, of which it is impossible to convey 

 any adequate idea by description, is a pile of red granite boulders of gigantic 

 size thrown abruptly in the plain." The very same may be said of part of the 

 Quitman Mountains, and I am of the opinion that a connection of the Cor- 

 nudos and Quitman Mountains might be proved a good deal easier than be- 

 tween the Guadaloupe and Wichita mountains, which Mr. Blake seems to 

 know only from what Mr. Bartlett and Capt. Marcy says about them, adding 

 to conclude with, "and there is little or no doubt of the stratified character 

 of these mountains." 



Mr. Blake regards these rocks as Carboniferous, and he is probably right 

 as far as parts only are considered. His opinion that probably granite could 

 be found in these mountains has since been confirmed. 



Major Emory's Report of the Boundary Survey of 1856, although mostly 

 confined to the line along the Rio Grande, gives a more general idea of the 

 geologic features of Trans-Pecos Texas, where more than anywhere else the 

 absence of continuity of the mountain ranges (hinted at in Major Emory's 

 report) manifests itself. 



Major Emory says:* "That range (Sierra Nevada), as well as the Sierra 

 Madre and the Rocky Mountains, about the parallel of 32°, lose their contin- 

 uous character and assume the forms that are graphically described in the 



* Boundary Survey Report, p. 44. General description' of the country. 



