ACADEMY OF NATURAL SCIENCES. 267 



nor were any fossils discovered, although portions of the rocks along their route 

 have since been proved to be prolific in organic remains. 



On all the geological maps of the whole territory of the United States which 

 have been published up to the present time, the region west of the Rocky 

 Mountains has been so misrepresented that it is quite impossible to trace any 

 approximation, or first hinting, at either the age or the outline of the principal 

 formations. On these maps the region lying between the Salt Lake and the 

 Sierra Nevada is usually left uncolored, or vaguely designated as " metamorphic " 

 with patches of " volcanic " and " desert quaternary " scattered through it at 

 random.* 



The first paper or publication issued, in which any definite information in 

 regard to the geology of Nevada was given, was that of Messrs. Meek and Engel- 

 mann, published in the Proceedings of the Philadelphia Academy of Natural 

 Sciences, for April, 1860. This paper gives the results of the examination by 

 Mr. Meek, of the fossils obtained by Mr. H. Engelmanu, who accompanied 

 Capt. J. H. Simpson on his explorations of 1858-59, or what is generally 

 known as " Simpson's Wagon Road Expedition." As the full report of this 

 expedition has never been published, we have no other information in regard to 

 the geology of the region traversed by Capt. Simpson's party than that given 

 in the paper above alluded to. The route followed on this survey was one near 

 the present Overland Stage Road, passing through a region then entirely unin- 

 habited by white men, but now dotted with mining camps and even towns of 

 considerable size — a region which has been proved to contain a large number of 

 argentiferous veins, and where mining operations have been carried on most 

 energetically and extensively during the last two or three years. 



The localities of fossils mentioned by Messrs. Meek and Engelmann, and in- 

 included within the limits of Nevada, are as follows : Long. 114° Ah', Lat 39 c 

 45', near what is now called Egan Canon, fragments of Trilobites, either of 

 Upper Silurian or Devonian Age, and " closely resembling Hamilton Group 

 Forms :"— Long. 115° 58', Lat. 39" 33', and Long. 115° 36', Lat. 39° 30' ; 

 at these two localities, situated in what are now the Eureka and White Pine 

 Mining Districts, a "group of fossils of decided Devonian type" was found. 

 This group consisted of Alrypa reticularis, A. aspera, or a closely allied species, 

 a small Productus,, and three new species of Spirifer. This is the most west- 

 erly point, on our territory, at which any fossils belonging to formations older 

 than the Carboniferous have, up to the present time, been discovered, so far at 

 least as any published record shows. Between Lon. 115° and 115° 30' and  

 Lat. 40° 10' "and 39° 20', is a group or series of hills, trending nearly north and 

 • south, and made up " of light yellowish gray, more or less argillaceous and are- 

 naceous subcrystalline limestones and slates." From these hills fossils were col- 



* On Professor Hall's Map "illustrating the general geological features of the country 

 west of the Mississippi River," which accompanied Emory's Mexican Boundary Report, 

 and was published in 1857, all of a broad central strip running along the parallel of 40° 

 through the center of Nevada, is colored as " lava and other igneous rocks," while the 

 western portion of the State has several broad belts of " Upper Carboniferous Limestone," 

 running north and south across it from Walker's Lake to Goose Lake. So far as I know, 

 no Carboniferous fossils have yet been found in that part of Nevada. 



