Geology and Natural History. 321 



Beds of Knoxville age and with a similar fauna occur in British 

 Columbia and probably in Alaska and Mexico. Correlation may 

 also be made with an indefinite upper portion of the Aucella- 

 bearing series in Russia, especially with the " Petschorian." 



It is a peculiar fact that this fauna has nothing in common with 

 the fauna of the Texan Comanche series, which must have been in 

 part contemporaneous. Not only are the species distinct but even 

 most of the genera are different, and yet the eastern sea with its 

 Comanche fauna at one time extended as far west as Arivechi in 

 Sonora, while the Mexican Aucella beds, which faunally seem to 

 belong to the Pacific basin and in part comparable with the Knox- 

 ville, are much farther east in San Luis Potosi. These facts have 

 an important bearing on the history of the continent, but their 

 exact interpretation must await more detailed stratigraphic and 

 faunal studies in Central Mexico. 



2. Contribution a V etude des lapifc. — In a paper in " Globe, 

 journal geographique" Tom. xxxv, Geneve, 1895, entitled La 

 topographie du desert de Plate {Haute- Savoie), M. Emile Chaix 

 has given a detailed description of the peculiar phenomena called 

 " Karr en f elder" by Heim, Fr. Becker and others, and "lapies" 

 by Charpentier, Rollier, Duparc and LeRoyer, etc. Lapies are 

 barren rock surfaces, high up in the Alpine glacial regions, 

 smoothed off in general, but crossed by shallow channels or 

 grooves commonly in the direction of the slopes; with deeper 

 crevasses, continued for long distances in a more or less straight 

 line and transverse to the slopes, though sometimes crossed by 

 others at nearly right angles and in line with the slopes of the 

 rocks. The author has mapped with great care the direction and 

 position of the crevasses ot the Desert de Plate, and has figured 

 typical examples of the peculiar structure in 16 photogravure 

 plates. 



Alter describing them in detail, and referring to the various 

 theories offered by other geologists in their explanation, he 

 adopts the view that the more superficial grooves and channels 

 (ciselures and rigoles) are the result of chemical erosion ; and that 

 the deeper crevasses are the result of torsion, as suggested by 

 the investigations by Duparc and LeRoyer. He concludes 

 that these two classes of phenomena, in the case of the Desert de 

 Plate, were produced at different times, the latter being of ancient 

 and the former of post-glacial origin, the edges of both having 

 been more or less rounded by later atmospheric and aqueous 

 agencies. h. s. w. 



3. The geographical distribution of marine animals. — In line 

 with Walther's "Bionomie des Meeres," Dr. Arnold E. Ortmann* 

 has contributed some interesting chapters to this rapidly crystalliz- 

 ing department of science, the geographical and geological 



*Grundziige der Marinen Tiergeographie. Anleitung zur Untersuchung der 

 geographischen Verbreitung mariner Tiere, mit besonderer Berucksichtigung der 

 Dekapodenkrebse von Dr. Arnold E. Ortmann (Princeton, N". J.), pp. 1-96, I 

 chart. Jena (Gustav Fischer), L896. 



