470 C. Schuchert — Notes on Arctic Paleozoic Fossils. 



In southern Baffin Island the strata appear to lie horizon- 

 tally. The Ordovician rocks and fossils are from widely 

 scattered localities, extending from the eastern Hall's Islet 

 into southwestern Fox Land. The locality, however, that has 

 furnished subsequent collectors the largest results and the most 

 definite stratigraphic information is at the head of Frobisher 

 Bay at Silliman's Fossil Mount (see Schuchert 1900). 



The Hall collections at Amherst also have Silurian fossils 

 from the southwestern corner of Baffin Island. These are 

 from Rescue Harbor in Cyrus Field Bay to the north of Blunt 

 Peninsula. 



Three general horizons can be made out in southern Baffin 

 Island, as follows : 



1. Ordovician. Dense gray to cream colored or whitish lime- 

 stones, in some places approaching lithographic stone. In 

 other places or other horizons the material is a fine-grained, 

 light pinkish, magnesian limestone, but in general the color 

 of all these limestones is the opposite of dark. As a rule 

 fossils are absent in them. In the purer and less dense 

 limestones very small fossils occur, chiefly Ostracoda. The 

 latter were first identified by Professor Emerson, and have 

 been recently restudied by Doctor R. S. Bassler, with the 

 following results : 



Leperditia canadensis Jones ) These two species seem to Bass- 



>• ler to be other forms than 

 Primitia muta Jones ) those indicated by Emerson. 



Primitia frobisher i Emerson = Eur yehilina frobisher i. 

 Beyrichia symmetrica Emerson = Drepanella symmetrica 



(related to the Richmondian B. richardsoni). 

 Krausella cf. anticostiensis Jones ) j -, -n. -, , ^> 



r j er 



Macrocypris cf. subcylindrica Jones ) 



Other associated fossils are a small Scenidium, sp. undet. 

 ( = Bhy?ichonella Emerson, p. 578), a small Plectambonites, 

 sp. undet. ( = Chonetes cf. striatella,^. 578), and fragments 

 of undeterminable trilobites ( = Emerson's Phacops and 

 Asaphits). 



The fine-grained, light pink, magnesian limestone from Hall's 

 Island has minute crystalline cavities that Emerson thought 

 might be casts of Tentaculites. These the writer could 

 not make out to be due to organisms. Other undetermin- 

 able fossils are Buthotrephu i (p. 575, fig. 1), and Stictopora 

 ramosa ? (p. 577, may be burrows). 



On the basis of the Ostracoda, the only reliable fossils 

 present, the horizon appears to be of Richmondian time, a for- 

 mation of very wide distribution in North America. Bassler 

 thinks the horizon and faunal realm represented are those of the 



