lamse] CANADIAN PALAEOZOIC CORALS. 35 



less, but often more widely separated, especially near the base. Lips of 

 the calyces more or less indented at the centre. As in C. Fischeri, 

 •Billings, and C. turgida, Rominger, the outlines of the calyces are more 

 rounded off or less sharply defined on one side of the corallum than on the 

 other, and on this side also faint polygons, surrounding the calyces, are 

 sometimes seen marking the limits of contiguous corallites at the surface. 



Abundant in the Hamilton formation of Ontario. Mural pores rather 

 small, few in number. Tabulae not observed, but they are mentioned by 

 Nicholson as being present in specimens examined by him. 



This species is distinguished from C. Fischeri mainly by the smaller 

 size of the corallites and the decidedly crescentic shape of the calyces ; it 

 appears to form a link connecting this genus with Cceniteg, Eichwald, in 

 which the walls of the corallites are very much thickened at Jthe surface, 

 and the calyces have the form of curved or linear fissures. 



Cladopora tubgida, Rominger. 



Cladopora turgida, Rominger. 1876. Geol. Surv. Mich., Foss. Corals, p. 48, pi. 

 XIX., fig. 2. 



Corallum in the form of flabellate expansions with rounded edges, 

 attaining a height of over 5 inches with a thickness of about 10 mm., 

 and of varying breadth. Corallites diverging upward and outward from 

 an imaginary inner axial plane, which is often nearer one side of the 

 expansion than the other, and issuing obliquely to the surface on both 

 sides and on the edges of the corallum ; calyces generally slightly over 

 1 mm. in maximum width, circular or transversely oval, with a slightly 

 thickened lip forming the lower boundary, and generally less than their 

 width apart. The corallites, owing to the excentricity of the axial plane 

 from which they ascend, are often longer on one side of the expansion 

 than on the other, the longer corallites having more prominent and less 

 oblique calyces than the shorter ones. Corallites almost circular and 

 greatly thickened as the surface is approached. Mural pores, distant, 

 rather small. What appear to be tabulae are seen in a few specimens at 

 distant intervals. The calyces, especially in the lower portions of the 

 «orallum, are frequently closed by opercula. 



Occurs in the Corniferous limestone of Ontario. A fragment of a 

 specimen of this species was collected by R. Kennicott at the " Ram- 

 parts," Mackenzie River, and is the property of the United States 

 ^National Museum at Washington. 



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