Reviews — Geological Survey of Minnesota. 323 



from the Dakota Language, by Prof. A. W. Williamson, the whole 

 of the Thirteenth Eeport is devoted to Geology. After a few notes 

 on reconnoitering trips into Pope County, and to Vermilion Lake, 

 we come to a paper on the Vermilion Iron-ores of Minnesota. Full 

 details are given of the various mines, with a table showing that in 

 ten 3'ears the gross product of metal has been 6,831,285 tons. Some 

 important analyses of the hard haematites are given. The crystalline 

 rocks of Minnesota, which appear to consist of gneisses and " soft 

 red granites," are treated of at pp. 36-38. Information as to the 

 Humboldt Salt Well in Kittson Co. is given, with details of a boring 

 to a depth of 644 feet ; " it remains for the future to determine 

 whether these salt-deposits shall become economically of importance 

 to the North-west." Details of other wells are given, bored appa- 

 rently for fresh water, one reaching a depth of 1800 feet (p. 54), 

 and a second 1160 feet (p. 57). The geological formations through 

 which these two wells pass are not given, but the latter begins 

 about 90 feet below the top of the St. Lawrence limestone. Two 

 interesting finds are those of Lingula Calumet and Paradoxides 

 Barheri, in the blood-red catlinite of the Great Pipestone Quarry in 

 Pipestone Co., a rock of Huronian age (pp. %5 — 72). Figures of 

 these interesting but rather obscure organisms are given in plate i. 

 A catalogue of the specimens registered in the General Museum in 

 1884 occupies nine closely-printed pages and contains many interest- 

 ing specimens of local and other rocks. Mr. Warren Upham (pp. 

 88 — 97) gives some notes on the geology of Minnehaha Co., Dakota, 

 where Potsdam quartzite seems to predominate. Professor H. W. 

 Winchell's valuable paper on "The Crystalline Kocks of the North- 

 west" (pp. 124 — 140), read before the American Association in 

 1884, is here jprinted. The peat, clay, and " Cretaceous " leaves of 

 Blue-earth Co. are noticed ; and a fossil Elephant tooth, from Winona 

 Co., is described and figured (pi. ii.) as being probably E. primi- 

 genius. The glacial deposits receive a due share of attention. Dr. 

 G. M. Dawson has a paper on the microscopic structure of some 

 Boulder-clays, and the organisms found in them (pp. 150 — 163). 

 He seems to have recognized certain minute bodies as Annelid jaws, 

 and compares them with those described by Dr. Hinde in the 

 Silurian and Devonian Eocks of Canada. Foraminifera are also 

 abundant, and a special paper by Messrs A. Woodward and B. W. 

 Thomas on some specimens from the Boulder-clay of Meeker Co. 

 is given at pp. 164 — 177. These fossils were found in fragments 

 of shale derived from the Cretaceous beds of Pembina Mountain, 

 in Manitoba, whence Dr. G. M. Dawson obtained similar specimens. 

 Two ]")lates are given (pi. iii. and iv.), but they are unfortunately 

 very inferior to the plates usually seen in American Governmental 

 Reports. 



The first paper with which we are concerned in the Fourteenth 

 Eeport is on some deep wells in Minnesota, by N. H. Winchell, with 

 an appendix at p. 348. The second is by E. 0. Ulrich on Lower 

 Silurian Bryozoa (pp. 57-103), mostly obtained from the Trenton 

 Shales. A list of 92 species is given, and of these about 50 are 



