204 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



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

 with longitudinal, rib-like markings which correspond to the septa 

 within. 



Internal structure, 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 centi-e, their general direction being in rows 

 which curve obliquely upward and outward. The general direction of 

 the arched carin;c which cross the sides of the septa throughout their 

 entire length, on the other hand, is uniformly upward and inward. 



Hay Eiver, forty miles above its mouth, E. G-. McConnell, 1881: two 

 pei-fect and well preserved specimens, both of which are figured. 



Phillii'SAStR/KA Hennahi, Lonsdale. 



Ai!lr:i'a llninain (pars), Lonsdale. 1S40. Trans. Geol. Soc. Lond., Sen !!, \ol. V, 



p. 09 7, pi. Iviii, fig. ;!. 

 AslTua Hennahi, Phillips. 1841. J'al. Foss Cornw., Dev. and W. Somera., p. 12, 



pi. vi, fig. 10. 

 Smilhia Hennahi, Edwards and Haime. 18.51. Polyp. Foss. des Terr. Pal., p. 



ArachnophiiUum Hennahi, McC 'oy. 1H51. Brit. Pal. Foss., [). 72. 



SmiUiia Hennahi, Edwards and Haicne. 18.53. Brit. Foss. Cor-, p. 240, pi. liv, 



fig. 4: Meel<, 1877, U. S. Geol. Expl. 40th Par., vol. IV, p. :!2, 



pi. ii, figs. () and 6a. 



Peace Eiver, near Vermilion Falls, Professor Macoun, 1875, two 

 specimens, and E. G. McGonnell, 1889, throe specimens, one of which 

 measures fully seven inches in its greatest diameter. Hay Eiver, 

 forty miles above its mouth, E. G. McConnell, 1887 : five specimens. 



Those from the Hay Eiver are very variable in external form, no 

 two of them being exactly alike. In one the corallum is '' depressed 

 jind moderately convex below," as in the type of Smithia VerriUii, 

 Meek; in another the basal portion is so deeply conic^al that the entire 

 depth of the coral is neaidy equal to its maximum breadth at the sum- 

 mit, while a third is neai-ly spherical. The epitheca, which is beauti- 

 fully presoi'ved in the deeply conical specimen, has its outer sui-face 

 finely and concentrically striated. The calices of the corallites, whose 



