V^ NOTES ON ORDOVICIAN TRILOBITES. IV. 

 New and Old vSpecies from the Chazy. 



By Percy E. Raymond. 



Since my article on the "Trilobites of the Chazy Limestone" was pub- 

 Hshed in these Annals, Vol. Ill, 1905, a number of new species and new 

 facts about old species have come to Hght, making it possible to add to 

 and correct the previous article in a number of ways. The material on 

 which the present article is based is in two collections, one made for the 

 Carnegie Museum by the writer in 1905 and 1906, and the other a small 

 but very important collection from Isle La Motte, made and submitted 

 by Professor George H. Perkins, State Geologist of Vermont. The latter 

 collection forms the basis of an article which will appear in the next report 

 of the State Geologist of Vermont, but Professor Perkins has very gener- 

 ously permitted me to describe the new material at this time. My 

 thanks are due him the more as he had intended describing these forms 

 himself, but he has, with great unselfishness, turned them over to me. 



ARTHROPODA. 



Subclass Trilobita. 



Order Hypoparia Beecher. 



Genus EoHARPES Raymond. 



Eoharpes antiquatus (Billings). 



The writer has shown elsewhere that the name Harpina was preoccu- 

 pied when used by Novak, and the name Eoharpes was suggested to take 

 its place. 1 



Order Opisthoparia Beecher. 



Family OLENID^ Salter. 



Genus Remopleurides Portlock. 



Remopleurides canadensis Billings. 



The thorax and pygidium of this species are very much like those of 

 Remopleurides salteri var. girvanensis Reed from the Llandeilo of the 



'^American Journal of Science, Series 4, XIX, 1905, 377. 



GO 



