318 The American Geologist. November, is95 
tain belt, ended the Mesozoic era; the Permian period, with the Appa- 
lachian revolution, terminated Paleozoic time; and the greatest of all 
the critical periods or revolutions divided the Archean and Algonkian 
ages from the Cambrian. 
Although the records of critical periods on account of the great geo- 
graphic changes and unconformity of the rock series are principally lost, 
these periods are believed to have been of long duration. Their changes 
of organic forms were, not simultaneous everywhere, but rather were 
propogated from place to place by waves of migration, which may have 
reached far beyond the limits of the physical changes. w. u. 
Ueber einige Fischreste des norddeutschen und hohmisclien Devons. 
By A. VON RoENEN. (Abhandl. der Konigl. Gesellsch. der Wissensch. 
zu Gottingen, vol. 40, pp. 1-37, pis. i-v, 1895.) In continuation of his in- 
vestigation of the Devonian fishes of Germany the author here pub- 
lishes accounts of the following species: From the upper Devonian, 
Ctenacanthics 9 e.rectics, nov., Coccoateiis inflatus, v. k., Brachydirus 
carinatus, v. k., Aspidicthys ingens, v. k., Anomalictliya neither, v. k., 
Phatyaspis tenuis, nov. gen. et sp., Holopiyeliius kayseri, nov., Glyp- 
tolepls traquairi, nov., Rhizodopsis dispersa, nov.; from the middle 
Devonian, Dinicthys efeUensis Kayser, Macropetaliethys agassizi v. 
Meyer., Osteolepis holzapfeli, nov.; from the lower Devonian, Macro- 
petaliethys prumiensis Kays., HolopetaKethys noraki, nov. (stage F. 
Bohemia). j. m. c. 
Sur une Faune dii sommet de la seri^ rhenane, a Pejyinster, Go4 et 
Tilff. By E. Kayser. (Ann. de la Soc. geol. de Belgique, vol. xxii, pp. 
177-216, pis. i-iv, 1895.) The author describes a recently discovered Bel- 
gian fauna which he refers to the upper part of the lower Devonian. 
The assemblage of species is especially notable for the considerable 
number of lamellibranchiates belonging to species and genera peculiarly 
American. "The American aspect which this fauna bears is one of the 
most interesting results of this work and is the f(jundation of a remark- 
able distinction between the lower Devonian of Belgium and that of the 
Rhine in which American analogies seem to be wanting. Belgium is 
not unique in this respect. This American expression of the lower De- 
vonian fauna reappears at the same horizon in the northwest of France. 
* * * The relations existing, during the lower Devonian, between 
the basin of Belgium and the north of France and that of North Amer- 
ica are perpetuated to the close of the Devonian period as shown by the 
existence of American species of Aviculidte mentioned by Gosselet and 
Freeh in the upper Devonian of Belgium, although these species are 
absent on the Rhine." j. m. c. 
The Stone Industry in 1894. By William C. Day. (16th Ann. Rept. 
U. S. Geol. Survey, pt. IV, 8.3 pp., 2 pis. 4-27, 1895.) It is with pleas- 
ure that we note the appearance of this portion of the results of the 
work on the mineral i-esources for the year 1894 before the end of 1895. 
(Part IV of the 16th Ann. Rept. of the Survey is entitled "Mineral Re- 
jsources of the United States, calendar year 1894.") In describing the 
