2 CONTRIBUTIONS TO CANADIAN PALiEONTOLOGy. 



The writer takes this opportunity of expressing his thanks to Mr. 

 Whiteaves for critical suggestions made during the progress of this report 

 and to Professor H. AUeyne Nicholson for the loan of a number of types 

 of Canadian species of fossil corals described in the two " Reports upon 

 the Palaeontology of Ontario " and in his " Palteozoic Tabulate Corals." 



ACTINOZOA. 



ZOANTHARIA. 



1. Madreporaria Perforata. 



FAVOSITIDiE. 



Genus Favosites, Lamarck, 1816. 



(Hist, des An. sans. Vert., vol. II., p. 204.) 



Calamopora, Goldfuss. 1826. Petrefacta Germanise, vol. I., p. 77. 



Smmonsia, Milne-Edwards and Hairae. 1851. Polyp. Foss. des Terr. Palieoz., p. 246. 



Aatrocerium, Hall. 1851. Palaeon. New York, vol. II., p. 120. 



Corallum of variable shape, massive or branching, composed of con- 

 tiguous, prismatic, polygonal corallites, that are placed in communication 

 with each other by circular mural pores ; walls thin and bearing on their 

 inner surface spiniform septa or squamulse ; tabulfe numerous, complete, 

 horizontal ; basal attachment small ; lower surface covered by an 

 epitheca. 



In this genus the corallum may be discoidal, hemispherical, spherical, 

 lobate, digitate or clavate, with numerous modifications, and also ramose. 

 The corallites are in close contact with each other, without a complete 

 amalgamation of the walls, and are either polygonal, subpolygonal or cir- 

 cular ; they emerge at right angles to the surface and in the ramose 

 forms diverge outward from an imaginary central axis ; they are either 

 equal or subequal, or are distinctly of two sizes, in which latter case the 

 larger ones are subangular or circular, and the smaller ones polygonal. 

 Septa are represented by tubercles or spines, arranged in vertical rows or 

 irregularly distributed, or .by horizontal, tongue-shaped processes 

 (aquamulse) also occurring in rows. The mural pores are placed in the 

 sides of the corallites, or close to or in the angles ; in the former case 

 they occur in one, two or three definite vertical rows or are disposed 

 without order. Longitudinal striations sometimes occur on the inner 

 surface of the walls, one to each space between the rows of pores. 

 Althougli the walls of the corallites are typically thin, a decided thicken- 

 ing is at times observable. Opercula are present, in some species, closing 



