IGNEOUS AND CRYSTALLINE ROCKS. 31 
F, G. Two samples of websterite, Hebbville, 6 miles west of Baltimore. Web- 
sterose. P. R. C. 1742. 
H. Bronzite from G. P. R. CG. 1743. 
I. Diopside from G. P. R. C. 1744. 
The rock consists entirely of bronzite and diopside. Analyses by T. M. Chatard, 
record Nos. 1094, 1123. 
J. Websterite, Oakwood, Cecil County. Cecilose. Composed of hypersthene and 
diallage. Analysis by W. F. Hillebrand, record No. 1755. Described by A. G. 
Leonard in Am. Geologist, vol. 28, p. 135. 
K. Cortlandtite, Ilchester, Howard County. Cortlandtose. Analysis by W. F. 
Hillebrand, record No. 1422. Published by Williams in 15th Ann., p. 674. The 
rock consists of olivine, pyroxene, and large hornblende crystals, the latter consider- 
ably altered to tale. P. R. ©. 1745. 
100. 48 | 100.52 | 100.56 | 98.84 | 100. 47 100.15 
2. GABBRO AND DIORITE. 
Rocks A to E, inclusive, described by G. H. Williams, but not in detail, in 15th 
Ann., pp. 673, 674. Some of the rocks, with other analyses, are discussed by him in 
Bull. 28. Analyses by W. F. Hillebrand, record No. 1422. 
“A. Olivine gabbro, Orange Grove, Baltimore County. JV. 1°. 1°, 2. Contains 
plagioclase, diallage, hypersthene, fresh olivine, magnetite, and apatite, and some- 
times hornblende. P. R. C. 1746. 
