weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1898. 63 
499 Lord (E. 0. E.}. On the dikes in the vicinity of Portland, Maine. 
Am. Geol., vol. xxii, pp. 335-346, pi. x, 1898. 
Describes the Glacial phenomena of the region and the occurrence 
and petrographic character of the dike rocks. 
500 Low (A. P.). Report on a traverse of the northern part of the 
Labrador peninsula from Richmond Gulf to Ungava Bay. 
Canada Geol. Surv., new ser., vol. ix, Rept. L, 43 pp., 4 pis., 1898. 
Describes the drainage and physical features and the occurrence and 
character of the Laurentian and Cambrian rocks and Glacial phenomena. 
501 Lucas (F. A.). Contributions to paleontology. 
Am. Jour. Sci., 4th ser., vol. vi, pp. 399-400, 1898. 
Describes a new genus and species of crocodile and a new species 
of Dinictis. 
502 See Leidy (Joseph), No. 481. 
503 Lukis (Ernest du B.). A new copper deposit in Mexico. 
Eng. and Mg. Jour., vol. lxv, pp. 279-280, 2 figs., 1898. 
Describes occurrence in the State of Puebla. 
504 Luther (D. Dana). The stratigraphic position of the Portage 
sandstones in the Naples Valley and the adjoining region 
[New York]. 
N. Y., 15th Ann. Rept., State Geologist, vol. i, pp. 13-14, 227-236, pis. 
i-ii, and geologic map, 1897; N. Y. State Mus. 49th Ann. Rept., vol. ii, pp. 
227-236, pis. i-ii, and geologic map, 1898. 
Describes the lithologic and faunal characters of the Portage sand- 
stones of the region. 
505 — — The economic geology of Onondaga County [New York]. 
N. Y., 15th Ann. Rept., State Geologist, vol. i, pp. 14-16, 241-303, pis. 
i-xxi, figs. 1-12, 1897; N. Y. State Mus. 49th Ann. Rept., vol. ii, pp. 
241-303, pis. i-xxi, figs. 1-12, 1898. 
Describes the character and occurrence of the Silurian, Devonian 
and Pleistocene formations and the occurrence of salt, gypsum, building 
stone and cement. 
506 Lyman (Benjamin Smith). Some illustrations of the influence of 
geological structure on topography. 
Franklin Inst., Jour., vol. cxlv, pp. 355-360, 4 pis., 1898. 
Describes a portion of the Punjab salt range and observes similar 
effects in Appalachian topography. 
507 — — Copper traces in Bucks and Montgomery counties [Pennsyl- 
vania]. 
Franklin Inst., Jour., vol. cxlvi, pp. 416-423, with map, 1898. 
Describes the occurrence and the character of the formation in which 
they occur. 
508 — — [Geology and its relation to topography.] 
Am. Soc. Civil Engrs., Trans., vol. xxxix, pp. 82-94, pi. ii, 1898. 
In discussion of paper by John C. Branner on the same subject. 
