Revleio of Recent Geological Literature. 327 
of Carboniferous rocks in which it may originally have been embraced. 
It is comparable to the basic volcanic tuffs that form a marked feature of 
the Keewatin, of the Archa-an of the "Northwest," in tlie United States. 
Clusnficidion of the Caphalopodd . In the May number of the Pruc 
Geol. Axsti. (London, 1892, xii) comparison tables were given of the 
various systems of classification. In the July number another list is 
given, designed to replace the former. Table i is Hyatt's classification 
1867-83; Tab. n is Fischer's, 1882-3; Tab. iir, Zittel's, 1884; Tab. iv. 
Bather's, 1888; Tab. v, Steinmann's, 1890. Bather's is the most remark- 
able mainly on account of its brevity, here showing Lipoprotoconchia, 
sub-ord. Nautiloidea. Sosiprotoconchia, sub-ord. Ammonoidea, sub- 
ord. Coleoidea (Osteophora, Chondrophora). 
Pcnfeldite, a new species. (Am. J. Sci. xlia', 261.1 Associated with an- 
glesite and laurionite from Laurion, Greece, Dr. Geuth has discovered a 
new lead oxy-choride of the composition PbO. 2 PbClg (CI. — 18.21, Pb — 
79.73 O — 2.06). Hexagonal, white, vitreous to greasy. Named after 
Prof. S. L. Penfield. 
Htuidbuch der Mincrnlofjie. The sixth part of this excellent work hj 
Dr. Hintze has just been issued. It treats principally of the serpentines 
sodalite nephelite, kaolinite and associated minerals. 
Protolenus, a neoo Genus of trilohites. G. F. Matthew. (Bulletin x. 
Natural History Society of New Brunswick, Sept., 1892. 
The new genus of which two species are described, Protohnus eteejans 
and P. paradoxides, occurs in the beds of Band b, division 1, of the St. 
John group, at Hanford brook, New Brunswick. 
The Gl'irinl Succession in Europe. James Geikie. (Trans. Roy. Soc. 
Edinburgh, Vol. xxxvn. Part 1, pp. 127-150.) 4to. with a map. This is a 
review of the evidence in Europe for the idea of three or more glacial 
epochs in Pleistocene time, and he concludes that at least four such 
epochs of cold can be established. He goes further, and extends alter- 
nating seasons of cold and warmth into Pliocene time, thus making five 
glacial and four interglacial epochs. 
COEEESPO^DEXCE. 
On tuk Keokuk Guocp.— The August No. of the Geologist con- 
tained an interesting paper on this subject by C. S. Beachler. In giving 
the literature he has overlooked a paper by the writer published in the 
American Journal of Science for October, 1890, in which the conclusions 
were practically identical with those now brouglit out by Mr. Beachler. 
In this paper a detailed section was given of the beds at Keokuk, and a 
study made of the fossil forms in wtiich it was shown that the Craw- 
fordsville crinoidal bed represents the thin sandy stratum sometimes 
