""«■ ] CANADIAN PALEOZOIC CORALS. 139" 



outer curve and a diameter at the top of 4 cent. Epitheca smooth, show- 

 ing faint annular transverse lines of growth and longitudinal depressed 

 septal lines. Calyx wide with almost vertical sides, flat at the bottom 

 with septa passing to the centre ; in the type specimen it is 28 mm. 

 across at the top and 18 mm. deep. Tabulate area large, occupying nearly 

 three-fifths of the entire diameter. Tabulae flat, moderately regular, from 

 •5 to 2 mm. apart, bent down at their edges, where a number of cystose 

 plates are introduced. Vesicular area narrow, made up of rather unequal 

 arched dissepiments, that curve upward and outward from the edges of 

 the tabulas ; the vesicles decrease slightly in size from within outward. 

 In the walls of the cup the septa are of equal length, but beneath in the 

 tabulate area many of them pass to the centre, whilst the remainder 

 apparently do not encroach on the tabulae ; septa numbering in all from 

 about one hundred and forty to one hundred and fifty. A septal fossette 

 is present at the edge of the bottom of the calyx on the side next to the 

 concave curve of the coral. The tetrameral arrangement of the septa is 

 well shewn in the type specimen. 



Locality and formation. — Rama's farm, near Port Colborne, Ontario, 

 Corniferous limestone; collector E. Billings, 1857. 



Cyathophyllum Spenceri, Lambe. 

 Plate XII, figs. 2, 2a, 26, 



Acervularia profunda, Billings. 1876. Rep. of Progress for 1874-76, Geol. Survey of 



Canada, p. 68. 

 Gyathophyllum profundum, Whiteaves. 1892. Contr. to Can. Pal^on., vol. I, pt, IV 



p. 267. 



var. Whiteaves. 1892. Ibid, p. 268, pi. XXXIV, figs. 4, 4a. 

 Gyathophyllum, Spenceri, Lambe. 1899. Ottawa Naturalist, vol. XII, p. 238. 



" Corallum composite, formed by closely connected, crowded, polygonal, 

 generally hexagonal corallites that diverge from a small base and form 

 thick somewhat explanate masses; largest specimen seen about 15 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 corallites and their assumption of a more nearly cylindrical 

 form. A line of contact between contiguous corallites is recognizable, 

 showing that each corallite is contained inside its own walls, also some 

 specimens have been preserved in such a manner as to admit of the coral- 

 lites being separated from each other along this line of contact. Surface 

 of corallites irregularly ribbed transversely, with fine growth lines between, 

 and longitudinally striated by shallow septal grooves. Corallites varying 

 in size in the same individual and in different specimens, from about 8 to 

 12 mm., in the majority of specimens, and from 10 to 17 mm. in the 



