SO^IE NEW MOLLUSCA FROM THE SILURIAN FORMATIONS 

 OF WASHINGTON COUNTY, MAINE. 



By Henry Shaler Williams, 



Of Cornell University, Ithaca, New York. 



INTRODUCTION. 



In tlio course of preparing the monograph on the Chapman Fauna 

 of Aroostook Coimty, Maine, I published two short papers in these 

 proceedings which properly belong to this scries of papers on the 

 Paleozoic fossils of Elaine, as follows: 



No. 1. A new Brachiopod, Rensselaeria mainensis, from the Devon- 

 ian of Maine. ^ 



No. 2. On the revision of the ]\Iollusk genus Pterinea Goldfuss.^ 



The present paper constitutes the third issue of this series. 



In the second paper the new genera Tolmaia, FollmanneUa, Acti- 

 nopterella, and Cornellites were described. 



The type-species of the genus Tolmaia is Pterinea lineata Goldfuss, 

 and the species Pterinea (Ptcronitella?) incurvata Clarke,^ described 

 from the Lower Devonic of Dalhousie, New Brmiswdck, is referred to 

 as probably belonging to this genus. The type of the genus FoU- 

 manneHa is Pterinea mainensis Clarke, from the Eodevonian of Moose- 

 head Lake region in Somerset Count}'", IMaine.^ 



The type of the genus Actinopterella is Pterinea radialis Clarke, 

 part, from the Chapman sandstone on Presque Isle stream, Chapman 

 Plantation, Ai-oostook County, Maine.^ 



The types of the hist two genera from the same localities had 

 already been described and named in manuscrij)t by the UTiter when 

 Clarke's i)aper was published, and other species of these genera are 

 described in the monograph on the Chaj)man fauna now (January, 

 1912) in course of publication by the United States Geological 

 Survey. 



> Proc. U. S. Nat. Mus., No. 1527, vol. 32, pages 287-269, published April 18, 1907. 

 ildem. No. 1600, vol. 34, pages 83-90, published AprU 17, 1908. 

 » N. Y. State Mus., Bull. 107, 1907, p. 210. 

 *Idein, p. 201. 

 'Idem, p. 207. 



Proceedings U. S. National Museum, Vol. 42— No. 1908. 



381 



