GEOLOGICAL SURVEY OF CANADA. 



Catalogue of the Lower Silurian Fossils of Anticosti, with 

 Descriptions of some of the Species. 



The Lower Silurian rocks of Anticosti occupy the west end and all of 

 the north side of the island except that portion which lies between Fox 

 Point and the eastern extremity, — a distance of fourteen miles. They 

 consist of pure and argillaceous limestones interstratified with a sparine 

 amount of shales, lying in nearly horizontal strata or with a gentle dip 

 towards the south. Their thickness is estimated at about 950 feet, and their 

 fossils show them to be of the age of the Hudson River formation, or very 

 nearly so. 



The south side, the east end, and the fourteen miles of the north coast 

 above mentioned as lying between Fox Point and the eastern extremity, 

 are occupied by rocks of the age of the Middle Silurian. A separate cata- 

 logue of the fossils of this portion will be given next after the present one. 



In the Hudson River formation the following species have been collected. 



PROTOZOA. 



No remains of Protozoa have been detected in the Lower Silurian, but 

 in the next formation above several species have been collected which may 

 perhaps belong to this division. 



ZOOPHYTA. 



Genus Heliolites, Dana. 



H. AFFiNis, B., Can. Nat. Geol. [2] , vol. ii, p. 427. — Corallum hemis- 

 pheric, globular, pyriform, clavato turbinate or tuberose, sometimes incrust- 

 ing other fossils in a thin layer ; cells usually circular, often sub-polygonal, 

 in contact with each other or barely separate, from half a-line to little less 



Note — Abbreviations. — H. R. = Hudsoa River formation. A. G. ^ Anticosti group. 

 B. 1= Billings. The names appended to the descriptions, such as T. C. Weston, 

 J. Richardson, &c., are those of the discoverers of the species. 



B 



