NUCULITES FROM THE SILURIAN FORMATIONS OF WASH- 

 INGTON COUNTY, MAINE. 



By Henry Shaler Williams 



Cornell University, Ithaca, New York. 



CONTRIBUTIONS TO THE GEOLOGY OF MAINE. 



In the year 1897 the writer began a study of the Paleozoic rocks 

 and fossils of eastern and northeastern Maine. 



As the work proceeded a series of publications have been issued, 

 by several agencies, illustrating the new facts regarding the geology 

 and paleontology as they have been elaborated. 



As all of these papers are more or less intimately related to each 

 other, it may be convenient for the reader to have before him a list 

 of them, with date, place of publication, and general nature of con- 

 tents. 



I. Contributions to the Geology of Mahie. Bulletin United States 

 Geological Survey, No. 165, 1900, 8, 212 pp., 14 pis. and maps. 



Part I. The Paleozoic faunas of Maine: a preliminary report upon 

 the Paleozoic faunas abeady known and upon new faunas recently 

 collected from Aroostook County, by Henry S. Wilhams. 



Part II. Geology of the Aroostook volcanic area of Mauie, hiclud- 

 ing an account of the clastic rocks of Aroostook County, by Herbert 

 E. Gregory. 



Part III. List of Locahties of Paleozoic, igneous and other crys- 

 taUine rocks examined during the seasons of 1897 and 1898, by 

 Henry S. Williams. 



In this bulletin the following geological formations are named and 



defined and preliminary lists given of their fossils, by which their 



position in the geological time scale is determined: 



9. Mapleton sandstone 1„ 



^r T>- J i ^Devonian. 



8. Moose River sandstone] 



7. Chapman sandstone 



6. Square Lake hmestone 



5. Ashland limestone 



4. Ashland shale > Silurian. 



3. Sheridan sandstone 



2. GraptoUte shales 



1, Aroostook limestone 



Proceedings U. S. National Museum. Vol. 54-No. 2225. ^^ 



