weeks.] PALEONTOLOGY, PETKOLOGY, AND MINERALOGY, 1901. 85 
w. 
771 Walcott (Charles D.). Cambrian Brachiopoda; Obolella subgenus 
Glyptias; Bicia; Obolus, subgenus Westonia; with descrip- 
tion of new species. 
U. S. Nat. Mus., Proc, vol. 23, pp. 669-695, 1901. 
772 The work of the United States Geological Survey in relation 
to the mineral resources of the United States. 
Am. Inst. Mg. Engrs., Trans., vol. 30, pp. 3-26, with map, 1901. 
Gives a general account of the work of the U. S. ( reological Survey in 
the development of the mineral resources of the country. 
773 Twenty-second Annual Report of the Director of the United 
States Geological Survey to the Secretary of the Interior, 
1900-1901. 
U. S. Geol. Surv., 22d Ann. Kept., Pt. I, pp. 1-207, pis. i-xxiv, 1901. 
Gives an account of the work of the U. S. Geological Survey for the 
year. 
774 Sur les formations Pre-Cambriennes fossiliferes. 
Int. Cong. Geol., Compte Kendu, viii session, pp. 299-312, 1901. 
Describes the lithologic and faunal characters of the pre-Cambrhm 
strata in various parts of the United States. 
775 Walker (B. E.). List of the published writings of Elkanah Bil- 
lings. 
Can. Rec. Sci., vol. 8, pp. 366-388, 1901. 
776 Wanner (Atreus). A new species of Olenellus from the Lower 
Cambrian of York County, Pennsylvania. 
Wash. Acad. Sci., vol. 3, pp." 267-272, pis. 31-32, 1901. 
777 Ward (Lester F.). Geology of the Little Colorado Valley 
[Arizona]. 
Am. Jour. Sci., 4th ser., vol. 12, pp. 401-413, 1901. 
Describes the character and occurrence of the several subdivisions of 
the Mesozoic strata of the region. 
778 [Review of "Sur quelques Microorganismes des combusti- 
bles fossiles," by B. Renault.] 
Science, new ser., vol. 13, pp. 577-581, 1901. 
779 The petrified forests of Arizona. 
Smith. Inst., Ann. Rept. 1899, pp. 289-307, 1901. 
780 Warren (C. H.). [Review of "The structural relations of the 
amygdaloidal melaphyre in Brookline, Newton, mid Brigh- 
ton, Mass.," by Henry T. Burr.] 
Am. Jour. Sci., 4th ser., vol. 12, pp. 80-81, 1901. 
