weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1898. 65 
519 Marbut (Curtis Fletcher). Geology of the Lexington sheet [Mis- 
souri], 
Mo. Geol. Surv., vol. xii, Pt. II, pp. 196-247, figs. 18-23, and geologic 
map and cross sections, 1898. 
Describes the physiographic features, the occurrence and character 
of the Carboniferous and Pleistocene formations and the occurrence of 
coal, building stones, and clays. 
520 Geology of the Richmond quadrangle, including portions of 
Kay and Carroll counties [Missouri]. 
Mo. Geol. Surv., vol. xii, Pt. II, pp. 252-308, figs. 24-29, and geologic 
map and cross sections, 1898. 
Describes the physiographic features of the region, the character and 
occurrence of the Carboniferous and Pleistocene formations, and the 
occurrence of coal, building stones, and clays. 
521 Geology of the Huntsville quadrangle, including portions of 
Randolph, Howard, and Chariton counties [Missouri]. 
Mo. Geol. Surv., vol. xii, Pt. II, pp. 312-371, figs. 30-37, and geologic 
map, 1898. 
Describes the physiography, the occurrence and character of the 
Carboniferous and Pleistocene formations, and the occurrence of coal 
and clays. 
522 Cote sans Dessein and Grand Tower [Missouri]. 
Am. Geol., vol. xxi, pp. 86-90, pi. x; Review by W. M. Davis, Science, 
new ser., vol. vii, p. 273 (| p.), 1898. 
Describes the character and origin of certain physiographic features. 
523 Marsh (O. C). New species of Ceratopsia. 
Am. Jour. Sci., 4th ser., vol. vi, p. 92, 1898. 
Describes two new species from the Ceratops beds. 
524 Jurassic formation on the Atlantic coast. Supplement. 
Am. Jour. Sci., 4th ser., vol. vi, pp. 105-115, 1 fig. ; Abstract, Science, 
new ser., vol. viii, pp. 145-154, 1898. 
Discusses a number of reviews of a former paper on this subject. 
525 Cycad horizons in the Rocky Mountain region. 
Am. Jour. Sci., 4th ser., vol. vi, p. 197, 1898. 
Gives a brief account of their occurrence in the Black Hills. 
526 The value of type specimens and the importance of their 
preservation. 
Am. Jour. Sci., 4th ser., vol. vi, pp. 401-405; Geol. Mag., dec. iv, vol.v, 
pp. 548-552, 1898. 
527 The origin of mammals. 
Am. Jour. Sci., 4th ser., vol. vi, pp. 406-409; Science, new ser., vol. 
viii, pp. 953-955, 1898. 
528 The comparative value of different kinds of fossils in deter- 
mining geological age. 
Abstract, Am. Jour. Sci., 4th ser., vol. vi, pp. 483-486; Geol. Mag., 
dec. iv, vol. v, pp. 565-568, 1898. 
Bull. 162 5 
