^"SE ] CANADIAN PALAEOZOIC CORALS. 161 



of the corallites, the sharp division between the septal area and the 

 enclosed tabulate area is noticeable, especially in transverse sections, 

 where the cut edges of the innermost dissepiments often assume the 

 appearance of an inner wall, which, however, is apparently not present. 



The single specimen in the collection has corallites in which the vesicu- 

 lar area is rather larger than is usual in Diphyphyllum, a development 

 suggestive of an approach to Gyathophyllum, to which genus, however 

 this coral cannot properly be referred, on account of its mode of growth 

 and increase ; it .shows affinities to both the genera Diphyphyllum and 

 Grepidophyllum, but is precluded from the latter by the apparent absence 

 of an inner wall. Additional material would doubtless throw light on 

 the inner structure of this coral and determine its generic and specific 

 affinities with more certainty. 



Locality and formation. — The fragment from near Woodstock, Ontario, 

 referred to by E. Billings ; Corniferous limestone. 



Diphyphyllum Simcobnse, Billings. (Sp.) 

 Plate XIII., figs. 6, 6a, 66. 



EridophyUum Simooense, Billings. 1859. Canadian Journal, new aeries, vol. IV., p. 132, 



fig. 27. 

 Diphyphyllum straminewm, Billings. 1859. Ibid, p. 135. 



11 11 Nicholson. 1874. Palseon. of Ont., p. 33, pi. V., fig. 6. 



EridophyUum Simcoense, Nicholson. 1874. Ibid, p. 34, pi. VI. , fig. 5. 

 Diphyphyllum, Simcoense, Rominger. 1876. G-eol. Sur. Mich., Foss. Corals, p. 122, 



pi. XL VI., figs. 3 and 4. 

 Amplexus or Diphyphyllwm, Whiteaves. 1892. Contr. to Can. Palseon., vol. I.,'pt. IV., 



p. 270, pi. XXXV., figs. 2, 2a. 

 Diphyphyllum Simcoense, Lambe. 1899. Ottawa Naturalist, vol. XII., p. 242. 



" Oorallum bushy, composed of flexuous, cylindrical corallites radiating 

 upward from a small basal beginning and rapidly increasing by lateral 

 budding so as to form colonies at times 25 cent, high and equally broad. 

 Corallites varying in diameter from 3 to 6 or 7 mm. frequently roughened 

 by annular swellings of growth and constrictions, covered by an epitheca 

 showing minor growth markings and longitudinal septal furrows. There 

 is a marked variation in different colonies in the number of horizontal 

 spurs connecting the corallites : in some specimens they are numerous, 

 from about 2 to 4 mm. apart vertically, springing outward from all sides 

 of the corallites, in others they occur at less frequent intervals, whilst in 

 some they appear to be almost absent. Septa short, bearing arched 

 carinse on their sides, divisable into two sizes, primaries and secondaries, 

 numbering in all from about thirty to forty, the primaries seldom reaching 

 half-way to the centre of the visceral chamber, the secondaries very short, 

 l— 5 



