ABSTRACTS AND DISCUSSIONS OF PAPERS 159 



the fifteenth, which is .spine- hearing, and those posterior to it, it resembles 

 Pcedumias, but differs from that genus in possessing at least 29 rudimentary 



segments. 



Five papers transferred from the program of the Geological Society of 

 America were then presented in order. The first of these was illustrated 

 by diagrams; 20 minutes. 



COMPARISON OF EUROPEAN AND AMERICAN EARLY PALEOZOIC 

 FORMATIONS 



BY AMADEUS W. GRABAU 



(Abstract) 



A study of the Durness limestone and associated formations of northwest 

 Scotland has convinced the author that most of this formation, generally 

 classed as Cambric, is of Lower Ordovicic or Beekmantownian age, separated 

 from the Lower Cambric by a disconformity which was located in the field. 

 The Biri limestone and Sparagmite of Norway will be considered in the light 

 of these studies and of the recent investigations of Rothpletz. The relations 

 of the Orthoceras limestone of Sweden to American formations will be con- 

 sidered, and some characters of the Siluric beds of Gotland, of Delarne, and 

 of England will be noted. Finally the Upper Siluric equivalent of the Ameri- 

 can Monroan in the Bohemian basin will be considered. 



A second paper by the same speaker followed. It was also illustrated 

 with diagrams; 20 minutes. 



SUBDIVISIONS OF THE TRAVERSE GROUP OF MICHIGAN AND ITS RELATION 

 TO OTHER MID-DEVONIC FORMATIONS 



BY AMADEUS W. GRABAU 



(Abstract) 



A detailed study of the Traverse group of Michigan, extending over 15 years, 

 has furnished the material for a subdivision of the group and for correlation 

 with the Milwaukee, Iowa, Ohio, Ontario, and New York mid-Devonic for- 

 mations. 



There was then presented a paper on Eocene algas, illustrated by many 

 striking lantern slides ; 20 minutes. 



SOME FOSSIL ALGffl FROM THE OIL-YIELDING SHALES OF THE GREEN RIVER 

 FORMATION OF COLORADO AND UTAH 



BY CHARLES A. DAVIS 



(Abstract) 



In northwestern Colorado and adjacent parts of Utah there are extensive 

 deposits of carbonaceous shales belonging to the Green River formation of 

 XII — Boll. Geol. Soc. Am., Vol. 27, 1915 



