88 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



from each other (one, two, or three times their diameter'), and are limited 

 by a small, well-marked, circular ridge, formed by the exsert edge of 12 

 subequal thick septa. The canaliculse of the coenenchyma are somewhat 

 irregular, and their parieties are rather thick. Diameter of the calices 

 about one third of a line." The authors of this species referred it to the 

 genus Heliolites, but the irregularity of the " canaliculse of the coenenchym " 

 suggests the possibility of the spaces between the corallites being filled 

 with vesicles rather than with tubules having tabute. If after further 

 research this surmise prove correct, Heliolites Grayi would of necessity 

 be removed to the genus Lyellia and the two species perhaps united under 

 the older name, as the similarity between the two forms would then be 

 such as to make this step expedient. 



Occurs in the Niagara group of Ontario. The type specimen was 

 collected at Cabot's Head, Georgian Bay, by Alexander Murray ; other 

 specimens are from lot 13, concession 7, Derby township, near Owen 

 Sound, Ont., R. Bell, and from Owen Sound, J. Townsend, 1874. 



Genus Lyopoea, Nich. and Eth., jun., 1878. 



Monogr. Sil. Poss. of Girvan, p. 25. 



"Corallum composite, massive, composed of tubular, sub- cylindrical or 

 hexagonal corallites, which are more or less completely fused with one 

 another. Walls of the corallites extraordinarily thick and dense, destitute 

 of mural pores. Columella absent. Septa rudimentary, few in number, 

 having the form of irregular ridges on the interior of the wall. Tabulae 

 complete. No coenenchyma." (Nich. and Eth., jun.) 



Lyopora Goldfussi, Billings. (Sp.) 

 Plate v., figs, 6, Ga and 7. 



Columnaria Ooldfussi, Billings. 1858. Rep. of Progress for 1857, Geol. Survey o 

 Cauada, p. 166 ; and Canadian Naturalist, vol. Ill, p. 420. 



Corallnm hemispherical, subspherical or forming irregularly shaped 

 rounded masses, sometimes as large as 2 or 3 inches high and 

 4 or 5 inches broad, composed of polygonal, subpolygonal or cir- 

 ular, moderately thick walled corallites that diverge upward and 

 outward from the base and are in close or partial contact with 

 each other. When the corallites are circular and only partially in 

 contact, small interspaces of irregular shape and size are left be- 

 tween them ; these are reduced to a minimum in size and number, 

 or are absent when the corallites are polygonal and touch each other 

 on all sides. The divisional lines between the walls of contiguous corallites 



