484 SCIENCE PROGRESS. 



of Protrachyceras Archelaus. Finally, in the Haupt- 

 dolomite, all the fossils, except the abundant Gervillia 

 exilis, are Raibl forms. 



The other papers on the Trias may be dismissed in a 

 few words. Kittl (15) has come to the conclusion that the 

 Marmolata and other allied limestones of Northern Italy 

 should he referred to the zone of Trachyceras Reitzi, and 

 not to that of T. Archelaus, in which Mojsisovics placed 

 them. He unites them with the Buchenstein rather than 

 with the Wengen beds. 



Bertrand (16), who until recently believed that the 

 " schistes lustres" of the French Alps were pre-Triassic, 

 has now reverted to the original view of Lory that they are 

 really of Triassic age. 



A controversial paper by Bittner upon the Alpine Trias 

 requires no more than mention for the present (30). 



JURASSIC. 



Among the Jurassic rocks there is but little to record. 

 The fourth volume, by H. B. Woodward, of the very im- 

 portant work on the Jurassic rocks of England and Wales, 

 has been published by the Geological Survey (17). But, 

 from the nature of the case, it does not lend itself to the 

 purposes of the present article. Attention may be directed, 

 however, to the description of the various kinds of lime- 

 stone. Many of the oolites have been formed by algae of 

 the Girva7iella type, but this mode of origin is not admitted 

 for all. 



Abroad we have a note upon the Liassic limestone of 

 the Oisans (Dept. Isere) in the French Alps (iS); and 

 another upon the boulders of East Prussia, with a descrip- 

 tion of a section at Popiliani on the Windau (S. of the 

 Riga Sea), from which neighbourhood it appears that these 

 boulders may have been derived (19). 



CRETACEOUS. 



The most remarkable of the Cretaceous deposits is 

 certainly the chalk, which is indeed one of the most peculiar 

 formations met with in any geological system. For many 



