Correspondence. 351 
sic Unios from the staked plains of Texas, C. T. Simpson: Fossil jelly 
fishes from the Middle Cambrian terrane, C. D. Walcott. 
Rept. Minn. Park Com. on the State Park at the Dalles of the St. 
Croix, 1897. The St. Croix river before, during and after the Ice age, 
Warren Upham. 
Mo. Geol. Survey, 63 pp., 7 pl^., 1897. Biennial report of the state 
geologist transmitted by the Bureau of Geology and Mines to the 39th 
General Assembly. C. R. Keyes. 
//. Proceedings of Scientific Societies. 
Proc. Ala. Indust. and Sci. Soc, vol. 6, pt. 2, 1896. Gold milling in 
Clay Co., Ala., at the Idaho mine, Joshua Franklin; Manganese ores 
of Georgia, W. M. Brewster. 
Jour, of the Western Soc. of Engineers, vol. 2, no. 1, February. 
Natural distortion of rock in place as shown on the Chicago drainage 
canal, C. L. Harrison. 
Bull. Geol Soc. Amer., vol. 8, pp. 59-86, pis. 3-9, Feb. 17, 1897. Dia- 
base pitchstone and mud enclosures of the Triassic trap of New Eng- 
land, B. K. Emerson. 
Ibid., pp. 87-112, pis. 10-13, Feb. 13. Sheetflood erosion, W J McGee. 
Ibid., pp. 113-126, Feb. 15. Earth-crust movements and their causes, 
Joseph Le Conte. 
Ibid., pp. 127-156, Feb. 17. Stratigraphy and paleontology of the 
Laramie and related formations in Wyoming, T. W. Stanton and F. H 
Knowlton. 
CORRESPONDENCE. 
Observations ON THE Cimarron Series.- In early Api-il of 1896, I 
traversed the Cimarron series from southern Kansas across parts of cen- 
tral and western Oklahoma and northwestern Texas, to obtain such new 
data as I might concerning the extension of the Ciitiarron series and its 
members southwestward from the Kansas-Oklahoma area described the 
month previous in my article, "The Permian System in Kansas." * In 
the September following, I examined of the western extension of this 
series in Clark and Meade counties, Kansas, and Beaver county, Ok- 
lahoma, certain small areas filling out gaps in my previous work. These 
two reconnaissances, which covered by rail, wheel, stage and saddle an 
extensive area, occupied but little more than a month altogether and 
were less complete than I could have wished, especially in the case of 
the southern one, but they sufficed to add considerable to the knowledge 
of the series. 
The more important of the new observations, with some related mat- 
ter, are here presented. 
Briefly, most of the subdivisions that I have described in the Cimar 
ron series in Kansas are more or less clearly recognizable in central Ok- 
lahoma, and some of them, at least, reach much farther southwestward. 
*Colorado College Studies, vi. pp. 1-48. 
