OLAF HOLTEDAHL. [SEC ARCT. EXP. FRAM 



limestone-conglomerates, and above these beds of limestone. In loose 

 pieces of this latter rock were found fragments of a Ptychoparia, probably 

 a new species, yet too incomplete to be specifically determined. The form 

 indicates Middle or Upper Cambrian. 



Above the limestone again come limestone-conglomerates and a 

 yellowish-white limestone, 100 m. thick. Here were found fragments of 

 trilobites, Ptychoparia sp., lllcenurus sp., besides numerous but very 

 badly preserved Or^oceras-specimens. Still higher were found beds of 

 quartz sandstone alternating with limestone, and finally a 30 m. bed of 

 limestone, where also traces of fossils were found, badly preserved gastro- 

 pods, among others an incomplete specimen of a Maclurea, and a frag- 

 mentary pygidium, belonging to a Bathyuriscus or Ptychoparia form. 



The stratigraphic position of the two fossiliferous limestones just men- 

 tioned is, in all probability to be found near the Cambro-Ordovician boundary, 

 in the highest Cambrian or basal Ordovician, the Ozarkian of ULRICH. 

 The total thickness of the above-mentioned sediments, which may be easily 

 studied on the east coast of Bache Peninsula, is not less than 7 800 m. 



Limestone beds with a distinctly younger fauna, are found in Norman 

 Lockyer Island, 18 km. to the north of Victoria Head. Here the following 

 species in well-preserved specimens were found. 



Halysites catenularia var. gracilis HALL. 



Calapcecia canadensis BILLINGS. 



Streptelasma corniculum HALL. 



Mesotrypa cf. discoidea var. orientalis BASSL. 



Callopora angularis ULRICH. 



Jiafinesquia deltoidea CONH. 



Plectambonites sericea Sow. 



Orthis tricenaria CONK. 



Triplesia sp. 



Rhynchonotrema incequivalvis CASTELN. 



Trochonema cf. umbilicatum HALL. 



Gonioceras occidentale HALL. 



Thaleops ovata CONR. 



Nileus (Bumastus?) sp. 



Leperditia fabulites CONR. 



This fauna it undoubtedly of the same age as the bulk of the forms 

 described by SCHUCHERT from Silliman's Fossil Mount, Frobisher Bay, 1 

 belonging to early Trenton. 2 



1 On the lower Silurian (Trenton) Fauna of Baffin Land. Proc. U. S. Nat. 

 Museum XXII, 1900, and further: Notes on Arctic Paleozoic Fossils. Am. Journal 

 of Science XXXVIII, 1914, p. 472. 



2 In WILLIS: Stratigraphy of North America, p. 217, ULRICH in a note considers 

 the horizon of Sillimans Fossil Mount to belong to upper Black River. 



