weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1895. 83 
543 Williston (S. W.). New or little known extinct vertebrates. 
Kans. Univ. Quart., vol. hi, pp. 165-176, pis. xiv-xix. 
Describes vertebrate remains contained in the museum of the Univer- 
oity of Kansas. 
544 Semi-arid Kansas. 
Kans. Univ. Quart., vol. iii, pp. 209-216, with map 
Gives a general description of the geology of Kansas and a geologic 
sketch map of the State. 
545 Note on the mandible of Ornithostoma. 
Kans. Univ. Quart., vol. iv, p. 61, pi. D. 
Remarks on the character of the skulls of Ornithostoma from the Kan- 
sas Cretaceous. 
54G Wilson (A. G.). The Upper Silurian in northeastern Iowa. 
Am. Geol., vol. xvi, pp. 275-281. 
Reviews the descriptions of Owen, Hall, and Keyes of the Silurian 
rocks of this region, and gives the results of the author's study of these 
rocks in Delaware, Jones, Dubuque, aud Clayton counties, Iowa. Men- 
tions fossils collected at various localities. 
547 Winchell (H. V.). [The genesis of ore deposits.] 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 957-962. 
In discussion of paper by F. Posepny on the same subject. 
548 and Grant (U. S.). Preliminary report on the Rainy Lake 
gold region [Minnesota]. 
Minn. Geol. and Nat. Hist. Surv., 23d Ann. Rept., pp. 36-105. 
Describes the occurrence of gold and the character and relations of 
the Laurentian, Coutchiching, and Keewatin rocks of the Rainy Lake 
region. Describes the occurrence of the gold veins. 
549 Winchell (N. H.). The age of the Galena limestone. 
Am. Geol., vol. xv, pp. 33-39. 
Reviews the paleontologic data regarding the age of the Galena lime- 
stone, presented by C. D. Walcott in a paper entitled "The Utica slate 
and related formations." Gives a brief statement of recent work of the 
Minnesota Geological Survey on the Lower Silurian rocks, and mentions 
the fossil characteristics of certain horizons. 
550 The stratigraphic base of the Taconic or Lower Cambrian. 
Am. Geol., vol, xv, pp. 153-162. 
Gives a historical sketch of the work on the Cambrian rocks of Eng- 
land, discusses the character of the pre-Cambrian rocks in general, and 
refers to the opinions of various writers on the Cambrian strata of 
Canada, New England, New York, and Pennsylvania. 
551 The paleontologic base of the Taconic or Lower Cambrian. 
Am. Geol., vol. xv, pp. 229-234. 
Describes the succession of Cambrian strata in Wales and the occur- 
rence of volcanic outbreaks during its deposition. Refers to the deter- 
mination of the succession of the Paradoxides and Olenellus faunas and 
the evidence of the nonconformity between the crystalline Archean rocks 
and the overlying sedimentaries. 
