Geology and Mineralogy. 467 



European lower Miocene, a creature similar in size and appear- 

 ance to the Indian elephant except that the trunk was inflexible be- 

 cause of its being- supported by the more elongated symphysis. In 

 Mastodon however the symphysis shortens, leaving the trunk free; 

 at the same time vestiges of the elongated condition of the jaw 

 occur in some mastodons and in the peculiar sharp process of the 

 symphysis of modern elephants. 



The Fayum researches have also thrown light upon the proba- 

 ble community of origin of the Sirenia, the Proboscidea and the 

 Hyracoidae. 



The Creodonts are also present of the family Hyaenodontidae 

 and the development of the Zeuglodonts from a creodont ances- 

 try is shown. The zeuglodonts of the Fayum, taken together 

 with a species, Procetus atavus, from the near-by Mokattan Hills, 

 form a series showing a complete transition so far as the teeth are 

 concerned from the Creodonts to the Zeuglodonts. 



The bird remains seem to be that of a true Ratite and suggest 

 the Ethiopian region as a point of origin of some at least of the 

 main sub-divisions of the Ratitse. 



The Reptilia are represented by crocodiles, turtles, and snakes. 

 There are no Amphibia and the fishes are either Elasmobranchs 

 or Siluroids and of no great interest. 



The summary points to the great importance of Africa as a cen- 

 ter of mammalian evolution, not alone of modern true mammals, 

 but of their Theriodont ancestors. This being the case, not only 

 the Tertiary, but the Mesozoic deposits of this region may be ex- 

 pected to throw much light upon the history of the Mammalia. 

 The Dark Continent seems to be a veritable land of promise to 

 the vertebrate paleontologist. r. s. l. 



3. Geology of the Owl Greek Mountains with Notes on 

 Resources of Adjoining Regions in the Ceded Portion of the 

 Shoshone Indian Reservation, Wyoming ; by N. H. Darton. 

 United States Geological Survey. Senate Document No. 219, 



59th Congress, 1st Session. Pp. 48, with 11 plates and 1 text 

 figure. Washington, 1906. — This paper, of the general form of the 

 bulletins of the IT. S. Geological Survey, is published as a Senate 

 document in response to a request from the Senate for such 

 information relating to the geology and natural resources of that 

 portion of the Shoshone Reservation which was to be opened for 

 settlement in July, 1906, as was in the possession of the U. S. 

 Geological Survey. The report has a geological map on the 

 scale of 4 miles to the inch, and many attractive photographic 

 illustrations. j. b. 



4. The Copper Deposits of the Robinson Mining District, 

 Nevada ; by Andrew C. Lawson. Univ. of Cal. Publications, 

 Dull, of the Department of Geology, vol. iv, No. 14, pp. 287-357. 

 May, 1906. — This bulletin gives a good account of the geology of 

 the Egan Range, one of the larger members of the Basin Range 

 system of mountains traversing eastern Nevada. The Archean 

 basement is not exposed, the rocks ranging in age from the Cam- 



