Catalogue Raisonné 233° 
and 172° 19 west longitude of Greenwich; but that he discovered nothing 
a the south-east which could lead to the presumption that there was an 
island. 
Notice of a large Greenstone Boulder in the Pentland Hills. 
By James D. Forses, Esq.—Edin. New Phil. Journ. No. XIV. 
This boulder was situated at the opening of a valley named Haw Dean, 
and lies, by the mean of two observations, at 333 feet above Mr. Forbes’s 
room, (Colinton house,) which is 415 feet above the mean level of the 
sea. It is of highly crystallized greenstone, weighing about 200 weight, 
sp. gr. about 2.895 : no greenstone rocks occur within many miles. Be- 
ing placed upon the actual declivity of a small but steep ravine, the au- 
thor remarks thst it seems physically impossible that had that valley ex- 
isted at the time of its journey, it should have been precipitated to the 
bottom of it. If it came from the last, it is not credible that it should 
have crossed the channel of the streamlet, aud ascended half way up the 
northern bank; and it is equally beyond explanation, that by any power 
short of a miracle, had it come trom the west, the course of so enormous 
a mass should have come to a stand under the influence of the tremen- 
dous impetus, of whatever kind, by which it was moved in the middle 
of a short and steep descent of this description. From these facts, Mr. 
Forbes considers the induction undeniable, that the excavation of the 
valley must have taken place subsequently to the deposition of this boul- 
er. 
Memoir on the Geognostical Structure of the Mountain of Cas- 
sel. By M. J. Desmirrer.—Societé de Sciences Agriculturales 
etd Arts de Lille. 
The formations of the mountain of Cassel, argillaceous in some parts, ap- 
pear to be principally composed of sandy layers, either horizontal, or 
regularly inclined with the slope of the mountain. Their colour varies 
between white, yellow, and orange yellow. Some are mixed with peb- 
bles of quartz, and friable stones of a deep red brown, formed of oxide of 
iron and agglutinated sand; others are strewed over with fossil shells, 
more or less well preserved. Deep beds are entirely composed of marine 
shells, united into an heterogeneous mass, often difficult to be broken. 
This formation is of a tertiary date. A superior sandy deposit evidently 
covers one of chalk, whose layers are, generally speaking, horizontal. 
A bed of plastic clay, unctuous, tenacious, and containing silex, covers 
in certain parts the chalky beds; and this clay sometimes contains ra- 
diated pyrites. The fossil shells which have been collected, are similar 
to the species found at Montmartre near Paris. At the foot of the moun- 
tain, more especially on the eastern side, we meet with numerous very 
perfect shells, which appear to be the product of a recent marine forma- 
tion: their analogies have been found living in the British Channel. 
Observations on the Monkeys of Sennaar, of Cordofan, and of 
Arabia ; by Messrs. Hempricu and EHRENBERG. (Verhand- 
lungen der Gesellschaft Naturforsch. Freunde in Berlin. Tom. I. 
Cah. 6.) 
.In the journey which Mr. Ehrenberg, and the late Mr. Hemprich, his 
companion, made in the north of Africa and the western parts of Asia, 
they met with the first monkeys in Africa at the 18th, and in Arabia in 
the 19th degree of latitude. They observed three species, the Cercocebus 
saboeus, the Cercopithecus pyrronotus, and the Cynocephalus hamadryas. 
The first species has been found wild in Darschakie, between the Sen- 
naar and the Dongala. The Cercopithecus pyrronotus is a species unno- 
ticed to the present day, nearly allied to the red patas of Senegal, but 
which is immediately distinguished by the superior brightness of its co- 
lours. A male individual of this species, which has been brought back 
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