loi W. A. Bell — Mississippian Formations of 



to the Pocono. The fauna of the Windsor series was con- 

 sidered by both Schuchert (1910) and Beede (1911) to 

 have mainly a Kinderhookian aspect, but certain of the 

 limestones were assigned by Schuchert to the Keokuk or 

 to a somewhat higher horizon. 



Scope of the present paper. — The present paper is con- 

 cerned primarily with conclusions reached after a detailed 

 study of the field relations and of the faunas of the marine 

 Windsor series, begun in 1912. As considerable interest, 

 however, attaches to the earlier Mississippian formations, 

 on account of their terrestrial fluvial origin, a brief de- 

 scription of them is included. These formations, the 

 Horton and the Cheverie, comprise what has formerly 

 been known as the Horton series. 



The treatment of the faunas of the Windsor series 

 necessitated the description of more than sixty new spe- 

 cies, and the report dealing with these faunas as a whole 

 will be published at a future date by the Geological Sur- 

 vey of Canada. Wliere new species are mentioned in the 

 present paper, use is made of manuscript names that are 

 subject to revision. 



Acknowledgments. — The field work of the present 

 study, which was completed in 1914, was rendered possi- 

 ble by the aid and encouragement extended by the Direc- 

 tor and Directing Geologist of the Geological Survey of 

 Canada. The preparation of the manuscript has been 

 done in the laboratories of the Peabody Museum of Yale 

 University, and the writer is particularly indebted to Pro- 

 fessor Charles Schuchert of that institution, from whose 

 suggestions the work was originally projected, for con- 

 stant supervision and inspiration. As Professor Schu- 

 chert is personally acquainted with the field, the value of 

 his criticism was greatly enhanced, while the Peabody 

 Museum collection of Windsor fossils gathered by him 

 was generously placed at the writer's disposal. 



Thanks are also due to Mr. J. E. Hyde, of Western Re- 

 serve University, Ohio, for suggestions made in the field. 



Although the work was interrupted by the war, the 

 writer was privileged, when in England, to study the col- 

 lections of Avonian fossils of the late A. Vaughan, that 

 are preserved in the Sedgwick Museum, Cambridge, and 

 the many courtesies extended him by Professor J. E. 

 Marr, of Cambridge University, are held in grateful re- 

 membrance. 



