80 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



lites and at very regular intervals apart but closer together, about six 

 occurring in a space of 1 mm. In transverse sections the corallites 

 exhibit twelve, delicate, sharply pointed septa of equal size, but whether 

 they are in the form of longitudinal ridges, septal spines or spinulose 

 carinas has not been determined from the specimens available for study. 

 The tubules are devoid of septa. The edges of the calyces are but 

 slightly elevated above the general surface of the corallum. 



Occurs in the Niagara formation and Lower Helderberg group ; speci- 

 men.s from the Lower Helderberg in the collection are from I'Anse a la 

 Vieille, Bale des Chaleurs ; from west of I'Anse a la Barbe, Bale des 

 Chaleurs. W. E. Logan, 1843, (identified by E. Billings) ; from Pointe au 

 Bouleaux, Bale des Chaleurs, W. E. Logan, 1843, and I'Anse au Gascon, 

 Bale des Chaleurs, R. Bell, 1862 ; from the Niagara there is one specimen 

 from Assiginack township, Grand Manitoulin Island, Manitouaning Bay 

 at "Fossil Hill," J. Townsend, 1883. 



Heliolites subtubulata, McCoy. (Sp.) 

 Plate II.. figs. 7, 7a. 



Palceopora interstincta, var. subtubulata, McCoy, 1851. Brit. Palseoz. Fossils, p. IC, pi. 



I. C, figs. 2, 2a, 26. 

 Heliolites Murehisoni, Milne-Bdwarda and Haime, 1851. Pulyp. Foss. des Terr. 



Palaeoz., p. 215. 

 ,1 „ Milne-Edwards and Haime, 1855. Brit. IFoss. Corals, p. 250, 



pi. LVII., figs. 6a, 6— e. 

 Heliolites microporus, Eichwald. 1860. Lethea Eossioa, p. 454, pi. XXV., figs. 7a, 



7b, 7o. 

 Heliolites suUubulatus, R&minger. 1876. Geol. Sur. Mich., Foss. Corals, p. 12, pi. 



I, fig. 4. 



Corallum in the form of explanate masses of irregular shape and 

 varying thickness, sometimes becoming somewhat hemispherical or pear- 

 shaped ; at times reaching a considerable size, 5 or 6 inches broad and 

 from 1 or 2 to 4 inches thick or high. Lower surface apparently 

 covered by a thin epitheca. Corallites parallel to each other and at right 

 angles to the surface, circular, averaging '75 mm. in diameter, and vary- 

 ing in different specimens from slightly under '75 mm. to 1 mm.; they are 

 distant from each other from 1, or even less, to 2 mm. The interstitial 

 tubules are polygonal, from three to eight in a straight line between 

 neighbouring corallites. Twelve septa of equal size nearly reach the centre 

 of the corallites. Horizontal tabulae occur in the corallites and tubules 

 at rather regular intervals, those of the former being farther apart than 

 those of the latter ; in the corallites there are three or four in a space 

 of 1 mm. and in the tubules five or six in the same distance. The cal' 



