58 Scientrfic Intelligence. 
descend in the crevasses to unknown depths. These crevasses are 
exceedingly numerous, and apparently increase in number on 
passing toward the inte erior, where not a plant, or stone, or patch 
of earth is seen over the oreat ocean of ice and snow, 1,200 miles 
in extent from north to south and 400 in breadth. r. Rush 
believes that the outpour of the Greenland oe of snow 
and rain in the form of glacier ice amounts to only two inches, 
while he estimates the fall at twelve inches; su Aliets as the evap- 
oration must be very small, a large portion of the remaining ten 
inches must be carried off by subglacier rivers.—‘‘ Nature” of April 
8th, from which these notes are taken, has a geological — of the 
Arctic region between the meridians ‘of longitude 20° 80° 
het , prepared by Mr. C. E. De Rance, the author of a series of 
papers on the Arctic regions, in the same Journ 
2. Bulletin of the U. § . Geological and Geographical Survey 
of the Territories: Nos. 2, 3 an nd 4, second series. 68 pp. 8vo, with 
‘maps and plates. Washington, May 15th, 1875.—The papers con- 
tained in number 2 are: Monograph of the Genus Leucosticte of 
Swainson, or gray-crowned pu eels Finches, by Ropert Ripeway ; 
Den ’ 
and yc i of the San Sean pare by F. M. Manaions on he 
Topography of the San Juan Country, by F. Ruopa ; on some pecu- 
liar forms of erosion in Eastern Colorado, with heliotype illustra- 
tions, by F. V. Haypen. No. 4 contains ie ee on the features 
of the Colorado or Front Range of the Rocky — by F. 
AYDEN, with a number of plates; on the Tert 
poda of Colorado, by 8. H. ScuppER; on a Natural Ati goel 
of the Falconide, by R. Ripeway 
Mr. Endlich, in his remarks on | the San Juan Country, states 
that for more than 4500 square miles, the surface is covered continu- 
ously with voleanic rocks. The following succession of strata was 
observed: (1) 800 feet of trachyte, mostly light-colored ; (2) 1200 
feet of red to brown trachyte, containing sanidite and some mica ; 
(3) 2000 to 2250 feet red to brown trachyte; (4) 3000 to 4000 of 
trachyte of various characters, ieee in all a thickness of 7000 to 
8000 eve a follow doleritic bed 
The of the region, affo poreigl angentiferous ennpee sphaler- 
ite, tetrahedrte, brittle silver, ete. of them gold, occur 
in the chyte, and are referre ng gore bdtiens or the begin- 
of the Tertiary, the era of thé a achytic eruption 
"one south and west the volcanic strata thin sale revealing 
the rock they overlie. Near the head of Cunningham ‘Creek the 
voleanic rocks form the crests of — while the valleys cut 
through into metamorphic rocks, w are quartzyte, chloritic 
rocks, mica schist, staurolitic neh ae and a coarse-grained 
granite. 
