220 The Ottawa Naturalist. [February 



est being sometimes slightly over 20 mm, in diameter. Outer 

 surface covered by an epitheca with numerous slight rings of 

 growth and with strongly marked septal furrows. Septa, tabulae 

 and dissepiments well developed. Septa numberiug from sixty 

 to over seventy in the large coralHtes, of two alternating sizes, 

 the primaries passing quite to or nearly to the centre of the vis- 

 ceral chamber, in the latter case leaving the tabulae smooth at 

 the centre, the secondaries small reaching generally less than 

 halfway to the centre. Tabulae forming a definite central zone 

 equal in breadth to about half the diameter of the corallite, flat 

 or slightly concave often deflected at the margin. Dissepiments 

 as a whole rather small but unequal in size, occupying the inter- 

 septal spaces between the tabulae and the outside wall, encroach- 

 ing at times on the tabulae. Calyces moderately deep, with steeply 

 ascending sides and most often with expanded thin margins. 



In the description given by Milne-Edwards and Haime of 

 this species (Brit. Foss. Corals) the septa are stated to be '' about 

 sixty in number, thin, equally developed." This is evidently a 

 misprint as far as the equality of the septa is concerned, as in 

 fig. la supplementing the description, the septa are shewn as of 

 two orders, numbering in all about sixty, half of which almost 

 reach the centre of the visceral chamber whilst the remainder 

 are only about half that size. 



Locality and formation. — Isle of Mann (Burnt Island), Lake 

 Temiscaming, Que. A. E. Barlow, 1893 ; Niagara formation. 



LiTHOSTROTION MACOUNII. Sp. nov. 



Favosites, (?), Whiteaves. 1877. Geol. Survey of Canada, Rep. 



of Progress for 1875-76, p. 98. 



Corallum astraeiform, composed of long, upright, slightly 

 flexuous, closely packed, distinct, prismatic corallites that have 

 five, six or seven sides and average about 3 mm. in breadth, 

 forming masses evidently of considerable size ; represented by 

 two fragments the largest of which is 8 cent, high and 6 cent, 

 broad. The corallites are somewhat irregularly marked by 

 decided transverse often slightly oblique growth ridges, and are 



