weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1896. 61 
438 Leach (J. C). Report of the State natural gas supervisor [Indiana]. 
Ind. Dept. of Geol. and- Nat. Res., 20th Arm. Rept., pp. 369-410, 1896. 
Describes the occurrence of natural gas in the Trenton limestones and 
the general geologic features of the area, including a map of the natural 
gas field of Indiana. 
439 Leckie (K G. E.). Notes on the Grand Lake coal field of New 
Brunswick. 
Can. Mg. Review, vol. xv, pp. 90-91, 1896. 
Describes the geologic features and occurrence and chemical charac- 
ters of the coal. 
440 Le Conte (Joseph). Elements of geology. A text-book for colleges 
and for the general reader. 
Fourth edition, 1896. D. Appleton & Co., N. Y. 
441 Leonard (A G.). Lead and zinc deposits of Iowa. 
Iowa Geol. Surv., vol. vi, 66 pp., 2 pis., 19 figs., 1896. 
Describes the character and occurrence of the various members of the 
Cambrian and Silurian series and the mode of occurrence of the lead 
and zinc ore bodies, and discusses their origin. 
442 Lead and zinc deposits of Iowa. 
Eng. and Mg. Jour., vol. lxi, p. 614, 1896. 
Describes the occurrence of lead and zinc in the Galena limestone. 
443 Lead and zinc. A description of the mines of Iowa in the 
Upper Mississippi region. 
Colliery Eng., vol. xvii, pp. 121-122, 1896. 
Describes the geology of the region and the occurrence of the ore 
bodies. 
444 Lesley (J. P.). Atlas to accompany Report F3 [Pennsylvania]. 
Pa. Geol. Surv., Atlas Rept. F3, 1896. 
Contaius a geologic map of Stone Mountain fault, geologic and topo- 
graphic map of parts of Huntingdon, Mifflin, Center, and Union counties, 
and a sheet of cross sections. 
445 Leverett (Frank). The water resources of Illinois. 
U. S. Geol. Surv., 17th Ann. Rept., Pt. II, 155 pp., pis. cviii-cxiii, figs. 
66-74, 1896. 
Describes the physiographic and drainage features and the occurrence 
and chemical composition of artesian waters. Includes a paper by J. A. 
Udden on the Paleozoic rocks at Rock Island, 111. 
446 Lewis (J. Volney). Corundum of the Appalachian crystalline belt. 
Am. Inst. Mg. Engrs., Trans., vol. xxv, pp. 852-906, 1896. 
Reviews the literature on corundum, describes the character of the 
peridotites and pyroxenites, amphibolites and secondary rocks of the 
corundum region, and the character, mode of occurrence, and distribu- 
tion of corundum. Includes a bibliography of the" subject and a map 
showing the location of the corundum deposits. 
