uu.be ] CANADIAN PALEOZOIC CORALS. 151 



oval in outline on account of the flattening of the corallum on the convex 

 side. Septa well developed, primaries and secondaries alternating, the 

 former generally reaching the centre, with their inner ends slightly 

 twisted, the latter about half the length of the primaries, carinated, con- 

 spicuous in the calyx and prominent on its rim ; in well developed indi- 

 viduals numbering in all from about sixty to seventy-five. Tabulae 

 apparently absent or very slightly developed. Dissepiments small, 

 occupying the spaces between the septa near their outer ends. Septal 

 fossette narrow, extending from the centre of the bottom of the calyx 

 outward to and enclosing the cardinal septum. 



Localities and formation. — Rama's Farm, Port Colborne, Ont., E. 

 Billings, 1857, and Hagersville, Ont., J. F. Whiteaves, 1890 ; Corniferous 

 limestone. Not uncommon. 



Cyathopiiyllum parvulum, Whiteaves. (Sp.) 



HeUophifllum parvulum, Whiteaves. 1891. Contr. to Can. Palseon., vol. I., pt. III., 

 p. 203, pi. XXVII, figs. 9, 9a, 10. 



"Corallum small, simple, either nearly straight, subcorneal and not 

 much longer than broad, or somewhat bent, irregularly distorted in growth 

 and proportionately rather narrower but apparently never either slender 

 or narrowly elongated. Calyx circular in outline, moderately deep : septa 

 thirty -six of each kind, their edges, as seen in the cup, presenting a 

 toothed appearance, which is due to the passing over them of arched 

 carime : primary septa reaching nearly to the centre at the bottom of the 

 cup : secondary septa very short and feebly developed : septal fossette 

 lateral, shallow. Epitheca thin, transversely striated and wrinkled, with 

 an occasional rather deep constriction, and marked also with longitudinal, 

 rib-like markings which correspond to the septa within. Internal struc- 

 ture, as seen in a longitudinal section through the centre of each specimen, 

 consisting of a narrow central tabulate area, surrounded by a broad, 

 external zone of vesicular tissue. The tabulate area occupies about one 

 fifth of the entire diameter, and the tabula? are straight, regular and 

 closely arranged. In the outer vesicular zone the vesicles are slightly 

 smaller and more regularly disposed towards the outside than near the 

 centre, their general direction being in rows which curve obliquely up- 

 ward and outward. The general direction of the arched carina 3 which 

 cross the sides of the septa throughout their entire length, on the other 

 hand, is uniformly upward and inward." (Whiteaves). 



Locality. — Hay River, Great Slave Lake, District of Mackenzie, fortv 

 miles above its mouth, R. G. McConnell, 1887; Devonian (Cuboides 

 zone). 



