Review of Recent Geological Literature. 1 2 5 
haps Archean, occupies the greater eastern part of the district. Its 
ore deposits are in fissure veins, provisionally referred to Cretaceous 
or Eocene time. In the Snake river valley and the valleys of the 
Boise and Payette rivers and their tributaries is a thick series of 
Miocene lacustrine and fluvial beds, including the Payette formation, 
more than 1,000 feet thick, of sands and sandstones, with plant remains 
shown by Knowlton to be of Upper Miocene age. Interbedded with 
the Payette deposits were vast flows of basaltic lavas, distinct from and 
earlier than the Snake River basalts and associated sediments, which 
belong to the Pliocene period. Both vein and placer mining have 
been very productive in the Idaho basin, but the latter is thought to 
have yielded nine-tenths of the total product of about $50,000,000 since 
the beginning of mining in 1863. The later mining in the region of 
the Boise ridge is chiefly in the vein ores. 
The Telluride mining district, in southwestern Colorado, occupying 
a grandly mountainous map sheet or cjuadrangle of a square quarter 
of a degree, is reported by Purington to have yielded in 1896 about 
$3,000,000, two-thirds being gold and the remainder silver and lead. 
Its total product, showing a steady increase since the first mining in 
1875, has been about $25,000,000. The rock formations, excepting a 
small Algonkian outcrop, range from the Trias to the Eocene, with 
later dikes, sheets, and laccoliths of diorite. The Eocene system is 
probably represented by the San Miguel conglomerate and sandstones, 
from 200 to 1,000 feet thick, and the overlying San Juan formation of 
tuft's, breccias, and massive flows of andesite, comprising a thickness 
of 2,000 or 3,000 feet. After the formation of all the rocks, but prob- 
ably closely succeeding the latest volcanic action, fissuring, with fault- 
ing, was attended by ore deposition. 
Part IV", Hydrography, contains four papers. Much geographic 
and geologic description is embodied in these papers, although they 
chiefly relate to water supply and to economic problems, largely of 
irrigation in the arid regions of the great plains and the Cordilleran 
mountain belt. w. u. 
Preliminary notice of the Etcheininian Fauna of Netu Foundlaint. 
By G. F. Matthew. [Bull. Nat. Hist. Soc. N. Brunswick, xviii, vol. 
iv, p. 189, St. John, N. B.. June, 1899.] 
Bv a note at the end it would appear that this article is complement- 
ary to one published in the Annals of New York Academy of Science, 
vol. xii, No. 2, pp. 41-56, in which the stratigraphy of the Etcheminian 
terrane in New Brunswick and Newfoundland was shown, and its rela- 
tion to the Cambrian exhibited. 
The fauna is peculiar and both in New Brunswick and Newfound- 
land is marked by the prevalence and large size comparatively, of Hyo- 
lithidae and Patellidse. 
The Hyolithidae are said to show a full development of familv charac- 
ters and although the genus Orthotheca has more species in this fauna 
than Hyolithes proper, the fauna is by no means primitive, as the Hyo- 
lithes belong to the advanced section Vlagnidorsati of G. Holm. 
The Patellidte are rejjresented by several ancient genera, among 
