22 TRANSACTIONS OF THE foot. 24, 
determinations by Dr. A. A. Julien. The rocks (except the dia- 
base) are shown to contain plagioclase (largely anorthite), hyper- 
sthene, hornblende, diallage, magnetite, menaccanite, and gar- 
net, They are both massive and gneissoid, Dr. Leeds gives six 
conclusions. J. The rocks of Essex Co. are parts of the Norian 
system and are composed of norites like those in Canada, 
Western Scotland, Norway and elsewhere. II. That they area 
stratified rock, which has undergone a metamorphism so profound 
as to cause them to be regarded by Emmons and others as 
massive. That the dolerites have come from another portion of 
lower lying, stratified rocks and have tilted the norites in their 
extrusion. III. The norites are marked by a paucity of silica 
due to the presence of bisilicates and to anorthite among the 
plagioclases. IV. The alkalies are deficient. V. Menaccanite 
is universal in both labradorite and pyroxenes. VI. The men- 
accanite contains chromium. The additions made by this paper 
to our knowledge of the chemical composition of these rocks 
are most praiseworthy, but the conclusions under II. are 
warranted by no commensurate field-work as evinced by the 
paper, and, remembering the mineralogy of the rocks, they 
would be considered in the estimation of petrographers as 
untenable. (See also A. R. C. Selwyn, Rep. Prog. Can. Sur,, 
1877-78.) 
Tn 1879 C. E. Hall published a paper on the “ Laurentian 
Magnetic Iron Ore Deposits in Northern N. Y.’’ (82nd Annual 
Report of the N. Y. State Cabinet, 1879, pp. 133-140.) The 
geology of the eastern Adirondacks is discussed very briefly by 
townships. The Archaean rocks are divided into: I. Lower 
Laurentian Magnetic Iron Ore Series. II. Laurentian Sulphur 
Ore Series. III. The Crystallino Limestones. IV. Labrador 
Series or Upper Laurentian with titaniferous ores. The 
relations of II. and III. are said to be uncertain, but later in a 
note the limestone of III. is stated to be later than IV. A 
geological map accompanies the report. 
G. P. Merrill, of the U. S. National Museum, has given 
attention to the serpentinous limestones as having some bearing 
on the Eozoon Canadense. This problematic association of 
serpentine and calcite had been previously announced from 
Warren Co. by A. M. Edwards, (Lyceum of Natural History, 
N. Y., Proc., 1870, p. 96.) Two papers have come from Mr. 
Merrill, the one on the ‘“ Ophiolite of Thurman, Warren Co.,” 
etc., Amer. Jour. of Sci., Mar., 1889; and the other, ‘On 
Serpentinous Rocks from Essex Co., N. Y, ete.,’’ Proc. U.S. 
National Museum, XII., 595, 1890. The serpentine appears to 
be both an alteration product from a white pyroxene, cores of 
