BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 25, pp. 421-434 September 15, i914 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



CAMBEIAN AND EELATED OEDOVICIAN BEACHIOPODA— 

 A STUDY OF THEIE UNCLOSING SEDIMENTS ^ 



BY LANCASTER D. BURLING 



(Bead before the Paleontological Society January 1, lOlJf-) 



CONTENTS 



Page 



Introduction 421 



Previous work 422 



Number of species and varieties occurring in the different types of sedi- 

 ment 423 



Genera and subgenera identified from but one type of sediment 427 



Lithologic, stratigraphic, and geographic range compared 428 



Data as to inclosing sediment classified and compared 429 



a. For species occurring more than once in the same section 429 



6. For all species occurring more than once 429 



Number of localities and number of species per locality in the different 



types of sediment 431 



Summary 433 



Introduction 



In his work on the Cambrian and related Ordovician Brachiopoda the 

 writer has had access to approximately 1,350 of the Cambrian fossil 

 localities represented in the collections of the United States National 

 Musenm,^ from abont 72 per cent of which, or 975, brachiopods have been 

 identified. All of this material and all known references to the occur- 

 rence of Cambrian Brachiopoda throughout the world were utilized in 

 this study of the nature of their inclosing sediments, an investigation 

 which was first suggested by Professor Schuchert in a letter to Mr. Wal- 

 cott, and seemed to be justified by the abundance of the material, its 



1 Manuscript received by the Secretary of the Geological Society April 10, 1914. 

 Published by permission of the Secretary of the Smithsonian Institution and the 



Director of the Geological Survey of Canada. 



2 This represents only the number which were available for the worlt on Monograph 51 

 of the U. S. Geological Survey on the Cambrian Brachiopoda. The collections of Mr. 

 E. O. Ulrich contain many brachiopods from the Cambrian, as that term is usually 

 defined. 



(421) 



