29 



Catalogue of the Fossils of the Anticosti Gkoup with Descriptions 



op some of the species. 



The AntiQCsti Group occupies all of the south shore of the island, with 

 the exception of a small portion at the west end lying west of Gamache 

 Bay, — the east end, and also about fourteen miles of the north coast 

 between the east end and Fox Point, They consist of argillaceous and pure 

 limestones with some interstratified shale fossilliferous throughout. In the 

 Geology of Canada they are described as consisting of four divisions, of 

 which the thickness of each is as follows : 



Division 4. Thickness 69 feet. 



" 3. " 540 " 



" 2. " 447 " 



" 1. ". 306 " 



1362 



Descriptive sections of these rocks will be found in the work cited, p. 

 298-304. 



PROTOZOA. 



Genus Receptaculites, Defrance. 



R ? INSULARIS, n. sp. — The specimen is a small cylindro-conical body 16 

 lines in length, 6 lines in diameter at the larger extremity, and 4 lines at 

 the smaller where it is broken off. The larger extremity has the edges 

 obtusely rounded and a shallow depression in the centre. The outer integu- 

 ment, or ectorhin, consist of small rough, convex, rhomboidal plates, the 

 greater diagonal of which is ^ of a line and the lesser J of a line. They are 

 arranged (on the larger extremity where alone they are preserved) in 

 spiral rows crossing each other as in the ordinary forms of the genus. 

 There seems to be a small rough pore at each point where the angles of 

 four plates meet. Where the ectorhin is removed, the cast of the inner sur- 

 face of the integument is covered with small round pits, the relation of 

 which to the plates cannot be clearly made out. It is clear that they must 

 correspond either to the depression at the angles of the plates or to a small 

 protuberance on the centre of the underside of each plate. In the latter 

 case they would represent the tubes of a true Receptaculites. The integu- 

 ment is rendered cellular by numerous small flat canals, some of which run 

 horizontally in a direction round the cylinder but none continuous, perhaps 

 only from one plate to another. Some of them seem to have a longitudinal 

 course transverse to that of the others, but their relations to each other or 

 to the plates cannot be made out. In one place there appear to be two 

 integuments, — an ectorhin and endorhin, but elsewhere only one. 



