REVIEWS 393 



the affinities of each with the Coblenzian faunas with which they show the 

 closest agreement, which consists of three identical species and twenty-seven 

 afi&liated ones, while the next nearest is with the Helderbergian and Oriskany 

 of the Appalachian gulf with eight identical and thirteen affiliated species. 

 Dr. Clarke concludes that "the inference is unavoidable that the predomi- 

 nating influence expressed in the Chapman congeries is that of the trans- 

 atlantic faunas of contemporary age." 



Again in Piscataquis and Somerset counties in northern and western 

 Maine to the west of Aroostook County are beds of quite fossiliferous sand- 

 stone and sandy shale. This fauna comprises about seventy species, some 

 of which are identical with members of the New York Oriskany fauna, as 

 Rensselaeria ovoides, Spirijer arenosus, Hipparionyx proximus, Rhipido- 

 mella musculosa (var.), etc.; others which are not identifiable with known 

 members of contemporaneous faunas; and finally a Coblenzian contingent, 

 which enforces and supplements that appearing in Aroostook County. 



As a result of these studies Dr. Clarke states in conclusion: "The 

 evidence then is fairly conclusive that during the period represented by the 

 Coblenzian-Oriskany the arenaceous epicontinental sediments were the 

 ground traversed by the Coblenz fauna westward along the North Atlantic 



continent The immigrant fauna taken as a whole is the direct 



descendant of the Coblenzian faunas, changed in part by variation and by 

 mutation, and hence contemporary therewith only in the sense of being 

 homotaxial; the lines of passage westward through the regions indicated in 

 New Brunswick and Maine were courses of migration only, not basins of 

 sequestration, fertile propagation, and dispersion as was the northern or 

 Gaspe passage." 



C. S. P. 



Age of the P re-Volcanic Auriferous Gravels in California. By J. S. 

 DiLLER. Proceedings Washington Academy of Sciences, Vol. 

 VIII, pp. 405, 406. February 13, 1907. 



The age of the auriferous gravels of the Sierra Nevada in California is gener- 

 ally given as late Miocene or Pliocene. This conclusion is based chiefly on fossil 

 plants and a few animal forms. The auriferous gravel period in all probability 

 was a long one and no considerable part of its flora has yet been connected directly 

 with its contemporaneous marine fauna in the same region. 



Mr. Diller has recently found a flora of ten species, determined by Dr. 

 F. H. Knowlton, in beds that carry a large and definite Eocene marine 

 fauna, studied by Dr. Wm. H. Dall. Three of these plants occur in the 



