414 Scientific Intelligence. 
ey: the conformability of all these schists and limestones. 
To er they occupy the region between the Archean and the 
Triassic area, 
(3) Mica schists, hornblendic, garnetiferous and talcose schists 
of Philadelphia, with soapstone and serpentine, which are 
scribed as resting aaeitommably on the preceding. A large part 
of this area is on the southeast side of the Archean between it and 
Delaware River. The nonconformity “may be mee to faulting, 
but they [the rocks] are nevertheless more rece 
The serpentines of Radnor township in Telaeelen County, and 
those of Easttown, Willistown, East and West Goshen are spoken 
of as “ undoubtedly altered beds of the South Valley Hill slates 
or Hudson River slates.” The serpentines of Lancaster County 
are referred to the same age, and also probably those of Chester 
a 
On the ~aagesrhe arn Volcanic Rocks of the Basin of the 
Firth of Forth: structure in the field and under the micro- 
scope ; by Arc one Gerk1x, Director H. M. Geol. Survey of 
Scotland. _ 82 pp. 4to, with three annie ser ahecagon a ecole 
Olivine augite-serpentine rocks, seen only at two localities ; 
Feldspar-magnetite rocks, or — or hyrites, which played an 
important part among the earlier eruptions of the Carboniferous 
period; and (4) Felsitic sab constituting a few dikes; and 
besides these there are fragment tal rocks or tufas. 
4. Contributions to the Geology of Eastern Massachusetts ; 
by Wm. O. Crossy. Occasional Papers of the Boston Society © 
Natural History, Vol. III. 288 pp, 8vo, with five plates and a col- 
ored geological map.—Mr. Crosby’s papers are very important 
contributions to the geology of Eastern New England. The rocks 
are described in detail, both as to their kinds “and distribution, 
and facts are given bearing on the question of age and illustrat- 
ing many points in geological science. Among the interesting 
questions discussed is that of the age of the conglome erate, asso 
(and in lines still fatbiecy and six to geven miles a 
o 
He remarks that the ieee contains — 0 go 
feet, and that of the slate nearly the same. Both are stated to 
be unconformable with the crystalline rocks adjoining, which are 
referred to the Archean. 
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