64 BIBLIOGRAPHY AND INDEX OF N. A. GEOLOGY, [bull. 162. 
M. 
509 Mabry (T. O.). The brown or yellow loam of north Mississippi and 
its relation to the northern drift. 
Jour, of Geol., vol. vi, pp. 273-302, 2 figs., 1898. 
Describes the character, relations, and distribution of the brown or 
yellow loam, its relation to the Lafayette and Loess formations, and 
discusses the origin and age of the Loess loam. 
510 McCallie (S. W.). A preliminary report on a part of the phos- 
phates and marls of Georgia. 
Ga. Geol. Surv., Bull. No. 5-A, 98 pp., 3 pis., 6 figs., 1896. 
Describes the general distribution of phosphates and the occurrence, 
character, and distribution of the Georgia phosphates. Discusses the 
origin of phosphates. 
511 King (F. P.), and Yeates (W. 8.). A preliminary report on 
a part of the gold deposits of Georgia. 
See Yeates ( W. S.), McCallie (S. W.), and King (F. P.), No. 941. 
512 McCalley (Henry). See Birkinbine (John), No. 78. 
513 McCharles (A.). Nickel mining in the Sudbury district [Canada]. 
The Mineral Industry, 1897, pp. 501-503, 1898. 
Includes brief notes on the occurrence of nickel. 
514. McClung (O. E.). Microscopic organisms of the Upper Creta- 
ceous. 
Kan. Univ. Geol. Surv., vol. iv, pp. 413-429, pi. lxxxv, 1898. 
Gives a general description of the forms occurring in the Upper Cre- 
taceous chalk of Kansas, with a description of several species, includ- 
ing one new one. 
515 McGee (W J). Geographic development of the District of 
Columbia. 
Nat. Geog. Mag., vol. ix, pp. 317-323, 1898. 
Describes the geologic and geographic history of the region. 
515a Madeira (George). See Day (W. C), No. 227. 
516 Maguire (Don). Gold mines of Mercur [Utah]. 
Mines and Minerals, vol. xix, pp. 81-83, 2 figs., 130-131, 1898. 
Describes the occurrence of the ore bodies of the region. 
'er 
517 Marbut (Curtis Fletcher). Geology of the Clinton sheet [Missouri]. 
Mo. Geol. Surv., vol. xii, Pt. II, pp. 20-104, 6 figs., and geologic map 
and cross sections, 1898. 
Describes the physiographic features, the character, occurrence, and 
relations of the subdivisions of the Carboniferous formations, and the 
occurrence of the economic products of the region. 
518 Geology of the Calhoun sheet [Missouri]. 
Mo. Geol. Surv., vol. xii, Pt. II, pp. 108-191, figs. 7-17, and geologic 
map and cross sections, 1898. 
Describes the physiographic features, the character of the subdivi- 
sions of the Carboniferous and Silurian formations, the geologic struc- 
ture, and the occurrence of coal, clay, building stones, and lime. 
