220 RECORD OF SCIENCE FOR 1886. 



90. Texas. — The State of Texas has recently published a report by 

 Shumard on the geology along routes traveled by the expedition be- 

 tween ludianola, Texas, and the valley of the Mimbres, New Mexico, in 

 1855, '56, and of Grayson County, Texas.* Although issued at this late' 

 date, and opinions on some of the broader questions have radically 

 changed, the report contains a great mass of valuable information. 

 Hill, in reviewing it, states that most of the stratigraphic deductions are 

 erroneous, and as shown by Marcou, the sections in the Cretaceous are 

 reversed. The supposed Upper Cretaceous in Grayson County is 

 now known to be Tertiary and the Lower Cretaceous, Upper.! 



91. Hill, in a general description of the geologic features of Travis 

 County, Texas, makes the interesting statement that the Cretaceous is 

 in two divisions, differing considerably in fauna and lithology and un- 

 conformable to each other, and it is pointed out that the lower division 

 lies altogether below the Dakota horizon. | Their areal distribution and 

 structural relations are described, and much local information given. 



92. Mexico. — Cope, in a report on the coal deposits near Zacuatipan, 

 Hidalgo, Mexico, describes the geologic features of that district. The 

 country is underlain by a silicious limestone said to be Cretaceous and 

 penetrated by numerous trap dikes and sheets. In the depressions in 

 this formation and its volcanic rocks lie regularly stratified horizontal 

 beds of Upper Miocene age, probably equivalent to the Loup Fork 

 series of the United States, and consisting of glass, volcanic ash beds, 

 and the carbonaceous shales, with lignite coal, often of good quality. § 



93. Nebraska. — In a description of the Lincoln salt basin, Hicks states 

 his opinion that these salt deposits in the Dakota group (especially those 

 of the lower part of the group) || are remnants of old Cretaceous salt 

 marshes, resulting from the evaporation of the sea water during the 

 deposition of the sands. 



CARTOGRAPHY. 



94. During the past year there have appeared two geologic maps of 

 the United States, one by McGee,^ the other by Hitchcock.** That of 

 the former is left uncolored west of the 112th meridian, together with 

 most of New Mexico, half of Arizona, and with the exception of a por- 

 tion of Nevada and the Puget Sound district. That of the latter is col- 

 ored in accordance with the scheme recommended by the International 

 Geologic Congress, and all but the northern part of Idaho and south- 



* A Partial Report on the Geology of Western Texas, by George G. Shumard 1855- 

 1860. pp. 145. 8vo. Austin, 1886. 

 t Am. Jour. Sci., iii, vol. 33, pp. — . 

 X Austin Statesman, Dec. 15, 1886. 

 ^ Am. Phil. Soc, Trans., vol. 23, pp. 146-151. 

 II American Assoc, Proc, vol. 35, p. 219. 



If U. S. Geo], Survey, Fiftii Aunual Report, pocket, 17" by 28". 

 •* Am. Inst. Mining Engs., Traus., 1886, 17' by 28". 



