weeks] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1895. 71 
443 Smyth (C. H. jr.). On a basic rock derived from granite. 
Abstract : Geol. Soc. Am., Bull., vol. vi, p. 4. 
Describes tbo character of a basic rock derived from granite in Jef- 
ferson County, N. Y. Gives the cbemical analysis of a specimen of the 
altei'ed material, and discusses the evidences as to the causes wliich have 
produced the alteration. 
444 Crystalline limestones and associated rocks of the north- 
western Adirondack region [New York]. 
Geol. Soc. Am., Bull., vol. vi, pp. 263-284. 
Describes the extent and character of the limestones, and the areas of 
gneiss, igneous rocks, granite, and diorites. Gives a more detailed 
statement of the occurrence, character, and relations of the three varie- 
ties of gabbro associated with the limestone. 
445 Smyth (Henry Lloyd). The Republic trough [Michigan], 
U. S. Geol. Surv., 15th Ann. Rept., pp. G08-630, pis. xxv-xxvi. 
Describes the distribution and character of the Archean and the 
Lower and Upper Marquette series and their contacts. Discusses the 
position, relations, and origin of the ore deposits. 
440 Snow (E. P.). The Fourmile placer fields of Colorado and 
Wyoming. 
Eng. and Mg. Jour., vol. lx, pp. 102-104. 
Describes the occurrence of gold placers in Routt County, Colo., and 
Carbon County, Wyo. 
447 The Hartville iron-ore deposits in Wyoming. 
Eng. and Mg. Jour., vol. lx, pp. 320-321. 
Describes the character and geologic relations of the ore body. 
448 The Douglas Creek placers, Albany County, Wyoming. 
Eng. and Mg. Jour., vol. lx, pp. 539-541, with map. 
Describes the occurrence of this placer in the Medicine Bow range. 
449 Spencer (Arthur C). Certain minerals of Webster County, Iowa. 
Iowa Acad. Sci., Proc, vol. ii, pp. 143-145. 
Describes the character and occurreuce of quartz, pyrite, celestite, 
and gypsum. 
450 Spencer (J. W.). Reconstruction of the Antillcan continent. 
Geol. Soc. Am., Bull., vol. vi, pp. 103-140, pi. 1. 
Describes the characteristics of old valleys and the deformation of 
land surfaces. Describes the submarine valley and fjords of the conti- 
nental and antillean regions, and discusses the evidences of elevation 
and subsidence in Pliocene and Pleistocene time. Discusses the evidence 
of the separation of tho Antillean basins from the Paeiiic and their con- 
nection with the Atlantic, and the biologic bearing of the physical 
changes of level. 
451 [On the formation of glacial terrace plains.] 
Geol. Soc. Am., Bull., vol. vi, pp. 460-461 (f p. ). 
In discussion of paper by C. H. Hitchcock on "High level gravels in 
New England." 
452 [Lake Newberry as* the probable successor of Lake Warren. | 
Geol. Soc. Am., Bull., vol. vi, p. 466 (£ p.). 
In discussion of paper by 11. L. Fairchild on the same subject. 
