148 Trans. Acad. Sci. of St. Louis. 



As this paper is not devoted to the description of the 

 fauna from a single bed, but to the description of a series of 

 faunas, the descriptions of species have been grouped under 

 five headings, each section being devoted to the fauna of a 

 single stratum. The general conclusions which have been 

 reached through the study of these faunas have been reserved 

 for treatment at the end, subsequent to the detailed descrip- 

 tions of all the faunas. 



The source of the materials upon which the faunal studies 

 of this paper have been based has been the same as in the 

 case of the Chonopectus sandstone fauna. The most im- 

 portant collection consulted is that known as the " White 

 Collection " in the museum of the University of Michigan, 

 for the use of which the author is deeply indebted to Prof. 

 I. C. Russell. Another small collection was contributed by 

 Prof. S. Calvin, State Geologist of Iowa, and still other 

 material has been collected in the field by the author. 

 Assistance has also been given by Dr. E. O. Hovey, of the 

 American Museum of Natural History in New York City, 

 through whose courtesy the writer was enabled to examine 

 the Burlington material in that museum. 



'to' 



Description of Species.* 



In many cases the descriptions of species published in the 

 present paper, are in the main copies of the original descrip- 

 tions. In all cases these copied descriptions have been placed 

 in quotation marks, although some slight changes have often 

 been introduced, especially in the case of the brachiopods 

 where the terms pedicle and brachial are introduced instead 

 of ventral and dorsal, and the modern usage of the terms 

 foramen, delthyrium, etc., is substituted in those cases where 

 it has been found necessary. In all cases measurements have 

 been changed from fractions of an inch to millimeters. 



* The Bibliographic references have been omitted from these descriptions . 

 For these the reader is referred to Bulletin 153, U. S. Geological Survey, 

 " A Bibliographic Index of North American Carboniferous Invertebrates," 

 by Stuart Weller, Washington, 1898. When species are referred to a dif- 

 ferent genus in this paper than in Bulletin 153, a reference is given to the 

 Bulletin. 



