2^8 The Ottawa Naturalist. [March 



developed, small, numerous, curving upward and outward 

 between the septa, appearing in radial sections at the corallites 

 as slightly convex plates enclosing narrow and com- 

 paratively long spaces. In tangential sections near the surface 

 the dissepiments are seen to be angular midway between the 

 septa, both havles of a dissepiment curving downward toward 

 each other convexly. The dissepiments on either side of a 

 septum generally correspond, so that at the surface with the 

 scant development of the septa in that part, they appear as 

 close-set horizontal wavy lines simulating the structure of CJiono- 

 pJiylluui, more particularly that of C. magnificum, Billings. 



Locality and formation. — South-west Point, Anticosti, divi- 

 sion 4 of the Anticosti group, four specimens collected by 

 J. Richardson in 1856. Portage Bay, Grand Manitoulin Island, 

 Lake Huron, R. Bell and H.G. Vennor, 1 865 ; Clinton and Niagara 

 formations. 



Cyatiiophyllum Spencer I, sp. nov 



Acervularia profunda, Billings. 1876. Geol. Surv. Canada, Rep. 

 Progress 1874-75, p. 68. 



CyatJiophyllnm profundum, Whiteaves. 1892. Geol. Surv, Canada, 

 Contr. Canad. Palgeont , vol I, pt. IV, p. 267. 



profundiiin, var., Whiteaves. 1892. Ibid, p. 268, 

 pi. XXXVI, figs. 4, 4a. 



Corallum composite, formed of closely connected, crowded, 

 polygonal generally hexagonal corallites that diverge from a 

 small base and form thick somewhat explanate masses ; largest 

 specimen seen about 1 5 cent, broad and 6 cent, thick or high. 

 Frequently spaces are left between the corallites at or near the 

 edge of the corallum due to the less crowded growth of the coral- 

 lites here and their assumption of a more nearly cylindrical form. 

 A line of contact between contiguous corallites is recogniz- 

 able, shewing that each corallite is contained inside its own 

 walls, also some specimens have been preserved in such a man- 

 ner as to admit of the corallites being separated from each other 



