235 
for the most part into serpentine; the garnet into minerals of the 
chlorite group; while the hornblende has generally withstood 
alteration. The paper of Mr. Lemberg contains a considerable 
number of analyses showing the composition of the original min¬ 
erals, as well as of the products of decomposition.— (Zeitschrift d. 
Deutsch. geol. Gesellschaft , 18V5, 531.) e. s. d. 
15. Selwynite , Noumeite, Garnierite .—Mr. G. H. F. Ulrich, 
in a letter dated Melbourne, Nov. 3d, 1875, states that the new 
species Selwynite, described by him, is not a homogeneous mineral. 
A microscopic examination shows it to consist of a felsite-like 
base, through which hydrous chromic oxide is disseminated, with 
occasionally a small octahedron of chromite. A similar method 
of examination has shown that the new nickel minerals (noumeite, 
garnierite), described by Professor Liversidge, are not homoge¬ 
neous. There is here a soapstone-like base, composed of hydrous 
silicate of magnesia through which either hydrous oxide of nickel, 
or hydrous silicate of nickel is densely distributed in small veins 
and roundish patches. Some of the ore gave an assay up to 
twenty per cent of nickel, and others as low as two per cent. 
16. Manual of Geology of J. D. Dana. —The following changes and corrections 
(besides some others merely typographical) have been made in the stereotype 
plates of the work since its first publication in 1874, and are needed by the copies 
of the earlier issues. 
Page xv, 17 1. from top, P. C. Carpenter for J. G. Cooper. Page 3, 8 1. fr. top, 
1 —1,200,000 for 1-200,000. P. 82, fig. 61f has been inverted; and the same on p. 
546. P. 147, 41. fr. foot, C. for P. P. 166, under fig., 4a Trenton for “ 4 Trenton.” 
P. 338, 2 1. fr. top, fig. 521, for “p. 521.” P. 344, in map, 9, 9, 9, far “ 8,” “ 8,” 
“ 8,” and 8 for “ 9.” P. 345, 18 1. fr. top, east for “ west.” P. 419, 4 1. fr. foot, 
southeast for “ southwest.” P. 427, 3 1. and 4 1. fr. top, over two for “ three or 
four.” P. 538, paragraph beginning with “ The absence” has been changed so as 
to make it state that between the meridian of 100° in Dakota and the eastern 
boundary of Oregon and California the mean annual precipitation is not, with 
small exceptions about the higher mountains, over 16 inches. P. 675, 15 1. and 
14 1. fr. foot, former for “ latter,” and latter for “ former.” P. 699, 16 1. fr. foot, 
yards for “feet.” P. 743, 18 1. fr. top, along the strike for “transverse to the 
strike;” and for the closing part of the paragraph has been substituted:—an 
effect due to compression by the pressure to which the rocks had been subjected 
and a consequent expanding in a transverse direction. P. 756. To the first para¬ 
graph has been added the remark [a suggestion to the author by Prof. Terrill] 
that the retaining of the warm Gulf Stream waters in the Atlantic would give the 
ocean a higher temperature than it now has, and that this higher temperature 
would be the occasion of an unusual amount of evaporation, and, therefore, of an 
extraordinary amount of precipitation and frequency of storms along the cold 
borders of the continent in the Glacial latitudes; so that the theory adopted for 
the origin of the cold of the Glacial period accounts for both the cold and the 
abundant precipitation. P. 589, Cetacean area removed from Cretaceous column. 
1. Notes on\ Agave; by Geo. Engelmann, M.D.—This is a 
modest title of a paper in the Transactions of the Academy of 
Science of St. Louis, Missouri, vol. iii, December, 1875. Sepa¬ 
rately issued it forms a pamphlet of 35 pages, 8vo. If we mis¬ 
take not it begins that volume; so that the pages of the pamphlet 
