Geology and Mineralogy. 323 



the close relations to the Lower Burlington are appreciated, and 

 the possibility of their partial equivalence is recognized." Bas- 

 sler's paper resulting from Springer's desires to adjust some of 

 the Mississippian crinoidal mixtures is reviewed below. c. s. 



5. The Waverlyan Period of Tennessee ; by Ray S. Bas- 

 sler. Proc. U. S. Nat. Mus., vol. 41, pp. 209-224, 1911.— This 

 important paper describes the Subcarboniferous strata on either 

 side of the Nashville dome and correlates them with those of 

 Ohio and the Mississippi valley south of St. Louis. The period 

 term Waverlyan is substituted for Mississippian on the ground 

 of supposed priority, but the author also states that this term was 

 not defined until 1869, the same year in which Alexander Win- 

 ched proposed Mississippi Group. It was Williams who in 1880 

 revived the latter term to cover all the American strata between 

 the Devonian and the Pennsylvanian. As thus used the term is 

 now thought to include two periods or disastrophic cycles, and 

 accordingly Schuchert intended to preserve this well-known 

 period name for the lower half, the strata with which Winched 

 was working. 



The Waverlyan period is again divided into three series, two 

 of which are named Osagian and Kinderhookian. The last 

 named series is in Tennessee, represented by the Riclgetop forma- 

 tion (new), to which the term Hickman was apparently applied 

 many years ago by Alexander Winched. c. s. 



6. Die vidcanischen Erseheinungen der Erde ; von Dr. Karl 

 Schneider. Pp. viii, 272 ; with 50 figures. Berlin, 1911 

 (Gebriider Borntraeger). — This volume gives an excellent sum- 

 mation of volcanic phenomena, its purpose being to enlarge on 

 facts rather than theories and to treat superficial igneous activity 

 to the exclusion of those of intrusive nature. The author notes 

 in the introduction that the subject of volcanism has passed 

 through a certain degree of stagnation during the past decade, as 

 the center of interest in igneous activity has passed to the under- 

 ground. This volume covers, therefore, a somewhat neglected 

 field. Nine chapters are given to the subject, of which those of 

 most timely interest are, perhaps, the nature of volcanism, the 

 larger forms of the moon's surface, the development of the volcanic 

 phenomena of the earth in different phases during the Cenozoic, 

 the genetic system of volcanic construction, the geograjmic 

 distribution of volcanoes of the present, and a catalogue of volca- 

 noes which have erupted within historic times. The volume is 

 thus seen to form a valuable reference book for the geologist 

 whose interests may touch this field of knowledge. J. b. 



7. On some 3Iineral Constituents of a Dusty Atmosphere ; 

 by W. N. Hartley. — The above subject is exhaustively treated 

 by W. N. Hartley in a paper read before the Royal Society of 

 London on May 11. By means of a small portable quartz spectro- 

 graph several series of spark spectra were photographed with 

 graduated exposures of 1, 5, 10, 20, 40, and 60 seconds, all on the 

 same plate. The electrodes in the first series were cadmium, iron, 



