= Fast 
70 | General Notes. [January, 
large angular masses, sometimes weighing more than fifty pounds, 
have been brought up in the trawl, and have not been washed 
away appreciably, notwithstanding the rapidity with which they 
have been drawn up through about two miles of water. In fact 
these masses of hard clay resemble large angular blocks of stone, 
but when cut with a knife they have a consistency somewhat like 
hard castile soap, and in sections are mottled with lighter and 
darker tints of dull green, olive, and bluish gray. When dried 
they develop cracks, and break up into angular fragments. This 
material is genuine clay, mixed with more or less sand, showing i 
under the microscope grains of quartz and feldspar, with some 
scales of mica. More or less of the shells of globigerina and other l 
foraminifera are contained in the clay, but they make up a very 
small percentage of the material. 
In all our ten localities, between 2000 and 3000 fathoms, the bot- 
tom has been “ globigerina ooze.” We have never met with the 
“red clay” which ought .to occur at such depths, according to 
the observations made on the cruise of the Challenger. 
The temperatures observed with the improved thermometers 
now used on the Albatross were between 36.4° and 37.0° F. 
in 2000 to 2600 fathoms. But temperatures essentially the same 
as these were also taken in 1000 to 1500 fathoms, and even in 965 3 
fathoms one observation gave 36.8° F. It follows from these ob- 
servations that nearly the minimum temperature is reached at 
about 1000 fathoms in this region. 
GEOLOGICAL News.—General—The water of the Atlantic, In- 
dian ocean, Red sea, and eastern part of the Mediterranean, has 
been shown by M. Dieulafait to contain manganese. The man- 
ganese can scarcely be perceived in sediments consisting of sus- 
pended matter, but is very perceptible when the water is free 
from suspended particles. In this way the well-known concre- 
tions of manganese in the deep seas were accounted for. He con- 
cludes that one of the conditions for the formation of chalk is 
the absence of foreign substances, and thus it may be expected 
that chalk should generally be rich in manganese. It was found 
that the quantity of manganese in fifty-six specimens of chalk 
` from the Paris basin was fifty times more than in specimens of 
granular colored limestone. 
Archean—M. Barrois calls attention, in his notes on metamor- 
phic rocks of Morbihan, to the way in which the schists gradu- 
ally lose their crystalline character as they recede from the gran- 
ite, until at length they pass into slate; while the metamorphic 
sandstones also change as they approach the granite, so as to 
show four distinct stages. 
Devonian.—M. Paul Vernskoff has published an important 
memoir upon the Devonian deposits of Russia, comprising : (1) 
their geographical distribution in the centre and north-west of that 
