176 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



ing an inner zone, in breadth about five-sevenths of the entire diameter, 

 turned down at the edges and raised centrally, in the form of a large 

 cone that appears as the striking projection in the bottom of the cup. 

 This conical boss is from 1 to over 1 -5 cent, in height, and is twisted in a 

 direction contrary to that of the hands of a watch when viewed from 

 above ; the carinal septa that reach the apex stand out as sharp ridges, 

 giving the cone a rugose appearance. Surrounding the broad tabulate 

 zone is a narrow vesicular area made up of rather large, convex dissepi- 

 ments filling the intersepted spaces and curving upward and outward. 



Mr. James Thomson and Professor Nicholson included in the genus 

 Acrophyllum, the two species A. Oneidaense, Billings, and A. pluriradiale, 

 Nicholson, although the latter species is stated in the original description 

 (Palseont. of Ontario, 1874, p. 21) to differ from the former, principally 

 in the absence of an external vesicular area, a structural difference that 

 would scarcely allow of their being classed in the same genus. The col- 

 lection of corals from the Corniferous formation of Ontario in the posses- 

 sion of the Geological Survey at the present time comprises no specimens 

 that agree with the description of A. pluriradiale, Nicholson. 



Localities and formation. — Abundant in the Corniferous- limestone of 

 Ontario. It has been collected also (loose) in the Devonian area south of 

 James Bay by George Barnston on the Moose River, and on the Albany 

 River near Old Fort Henley ; by R. Bell at the Grand Rapids of the 

 Mattagami River, and on the Moose River, in 1895 ; at Long Portage, 

 Missinaibi River to Moose Factory, by R. Bell, in 1877. 



Genus Lithostrotion, Fleming. 1828. 



Lithostrotion, Fleming. 1828. British Animals, p. 508. 



" Ocrallum fasciculate or astrseiform, composed of cylindrical, slender 

 corallites, with an epitheca. Columella styliform, compressed laterally ; 

 septa well developed, sometimes reaching the columella. Central part of 

 the corallite crossed by irregular tabulae, peripheral part occupied by a 

 vesicular endotheca. Carboniferous." (Zittel : Traite de Paldontologie.) 



Type species. — L. hasaltiforme, Fleming. 



Lithostrotion Macouni, Lambe. 

 Plate XIV., figs. 11, 11a, 116. 



Favosites~{p.), Whiteaves. 1877. Rep. of Progress for 1875-76. Geol. Survey of Can- 

 ada, p. 98. 

 Lithostrotion Macounii, Lambe. 1899. Ottawa Naturalist, vol. XII., p. 220. 



"Corallum astrseiform, composed of long, upright, slightly flexuous, 

 closely packed, distinct, prismatic corallites that have five, six or seven 



