296 Miscellaneous Intelligence. 
rocks described in Europe as the mountain limestone, or sometimes ma 
the carboniferous, or metalliferous, or encrinital limestone.- And it be- 
longs, yet more especially, to a subdivision of this group known popu-. 
larly, where it occurs in the west, as the cliff limestone, and described 
\ under that name by the geologists of Ohio. s 
“This last is the rock formation in which the lead, copper, iron, and 
. zinc of the region under consideration, are almost exclusively found} 
j and its unusual development doubtless much conduces to the OR 
nary mineral riches of this favored region. It therefore ad 
shall hereafter receive, particular analysis and attention. cs ib 
‘In the northern portion of the district surveyed, an inte erosthlgadt r 
ry 
consin river ; whence (if we may rely on the representations of School- 
craft and others) they extend: north, even to the falls of St. Anthony. 
“ These strata are interesting, first, as being the only instance known 
to me, in the valley of the ‘Mississippi, in which the rocks underlying 
the blue limestone can be seen emerging from beneath it to the surface; _ 
and secondly, as apparently supplying an example of those meronten 
of neighboring.strata, to which I have already pe as being os ‘ 
exceptions to the invariable order of geological superposition.” 
20. Academy of Natural Sciences of Philadelphia._The wef 
of this institution, and the interests of science in general, hav 
greatly promoted by the munificent liberality of Dr. Thomas B, Wik 
son, a citizen of Philadelphia, and a member of the Academy. This 
gentleman has recently. eae in Paris, the splendid collection of 
birds known as the Rivoli Collection; which is admitted to have few 
tivals, either in respect. to:the beauty or the variety of its specimens. 
e number exceeds 10,000, embracing 5,000 species, mounted and na- 
med, and illustrating. all the diversities of plumage incident to the = 
ference of age, sex wad locality. 
Dr. Wilson has. not only become the proprietor of this retinal 
collection ; he has also resolved to place it in the Academy, where it” 
will be accessible to the public, and thus diffuse the knowledge of one 
of the most pleasing branches of natural history. But the present Hall 
of the Academy, spacious as it is, is too small to accommodate this gi- 
gantic acquisition, and it therefore becomes necessary to extend the 
building, which can only be accomplished at a heavy expense. But 
Dre ‘ilson, with a oot that: has few ens taee has removed this. 
; sole nse; 
ee yao 
