weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1894. 25 
32 Blake (William P.). On the origin of ancient quartz rocks. 
Science, vol. xxiii, pp. 141-142. 
Discusses the origin of quartzites of pre-Cambrian strata. 
32a Boyle (0. B.). A catalogue and bibliography of North American 
Mesozoic Invertebrata. 
Abstract: Am. Geol., vol. xiv, p. 330 (£ p.). 
Noticed in Bibliography and Index for 1892 and 1893. 
33 Branner (John 0.). Elevations in the State of Arkansas. 
Ark. Geol. Surv., Ann. Rept. 1891, vol. ii, pp. 77-152. 
Gives the elevations, determined by different methods, of certain 
points in the State. 
33a Observations upon the erosion in the hydrographic basin of 
the Arkansas River above Little Rock [Ark.|. 
Ark. Geol. Surv., Ann. Rept. 1891, vol. ii, pp. 153-166. 
Abstract: Jonr. of Geol., vol. ii, p. 866 (^ p.). 
Noticed in Bibliography and Index for 1892 and 1893. 
34 Magmatic observations and meridian monuments established 
in Arkansas. 
Ark. Geol. Surv,, Ann. Rept. 1891, vol. ii, pp. 168-176. 
Describes the location and character of monuments and the mag- 
matic observations of certain points in Arkansas. 
35 Bibliography of the geology of Arkansas. 
Ark. Geol. Surv., Ann. Rept. 1891, vol. ii, pp. 319-340. 
Gives a list of papers on the geology of Arkansas, arranged alpha- 
betically by authors' names. 
30 The geological surveys of Arkansas. 
Jour, of Geol., vol. ii, pp 826-836. 
Reviews the work of the several geological surveys of Arkansas. 
37 Brewer (W. M.). Notes on the Alabama gold ores. 
Eng. and Mg, Jour,, vol. lvii, pp. 57-58. 
Describes the gold ore deposits of Tallapoosa County, Ala. 
38 Broadhead (G-. 0.). Geological history of the Missouri Paleozoic. 
Am. Geol., vol. xiv., pp. 380-388. 
Describes the topography of the Ozark plateau, the mode of deposi- 
tion of the strata and their deformation during Paleozoic time, and 
the dislocations and erosion that have since taken place. 
39 Brbgger ( W. C). On the formation of pegmatite veins. 
Can. Rec. Sci., vol. vi, pp. 33-46 and 61-71. 
Reviews the previous theories as to the formation of pegmatite 
veins and gives a resume of the author's conclusions, indicating that 
these veins are magmatic eruptive veins formed under peculiar con- 
ditions. 
40 Brooks ( W. K.). The origin of the oldest fossils and the discov- 
ery of the bottom of the ocean. 
Jour, of Geol., vol. ii, pp. 455-479. 
Discusses the evidences which indicate that the fauna of the Lower 
Cambrian is an approximation to the primitive fauna, and that prior 
to the Lower Cambrian animal life was represented by minute ani- 
mals not likely to bo preserved as fossils. 
