160 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



connected and held together by numerous strong, robust, lateral out 

 growths. Corallites seldom much more than their thickness apart, varying 

 in diameter from about 7 to 14 mm., often exhibiting strongly marked an- 

 nular swellings and constrictions at irregular intervals, frequently coming 

 in contact and growing together without the intervention of connecting 

 processes. Outer surface consisting of an epithecal covering with, as in 

 other species of the genus, faint transverse growth lines and regular 

 longitudinal linear depressions indicating the position of the septa. Sep- 

 ta strongly carinated, numbering from about forty-five to sixty, of two 

 alternating lengths, the primaries reaching little more than half-way to 

 the centre, the secondaries about two-thirds the length of the primaries. 

 Tabula? broad, flat, directly transverse, about six to ten in a space of 5 

 mm. Vesicles in two or three, generally two rows in the interseptal 

 spaces between the tabulae and the wall. According to Billings the 

 coralla reach a width of from 2 to 3 feet. 



D. Vemeuilanum has larger and more robust corallites than the other 

 species of Diphyphyllum referred to here as occurring in the Silurian and 

 Devonian rocks of Canada. 



Locality and formation. — Common in the Corniferous limestone of 

 Ontario. 



Diphyphyllum strictum, Milne-Edwards and Haime. (Sp.) 



Eridophyllum strictum, Milne-Edwards and Haimp. 1851. Polyp. Foss. des Terr. 

 Palseoz., p. 424, pi.. 8, fig. 7. 

 ii ii Billings. 1859. Canadian Journal, new series, vol. IV., p. 133. 



Nicholson. 1875. Geo!. Surv. of Ohio, pt. II., p. 238 and Palaeon. 

 of Ont., p. 74. 



A specimen from the Corniferous formation collected by A. Murray 

 and referred by Mr. Billings in 1859 to this species may be described as 

 follows : — Corallites subparallel, slightly flexuous, separated from each 

 other by spaces on an average rather less than half their diameters in 

 width, from about 4 to 12 mm. thick, with numerous alternating sharp 

 annular swellings and constrictions, and developing rather feeble con- 

 necting processes. Increase by lateral gemmation, the young corallites 

 springing from the upper surface of the connecting processes and growing 

 upward parallel to the parent corallites, frequently for some distance with 

 little increase in size. Septa, with arched carina on their sides, about 

 fifty in number in adult corallites, of almost equal length, reaching half 

 way to the centre where they abut against the tabulae. Dissepiments 

 small, regular, entirely filling the interseptal spaces. Tabulae flat or con- 

 cave, often turned up at their margins, from four to ten occurring in a 

 space of 5 mm. Epitheca showing fine transverse growth lines and longi- 

 tudinal septal markings. Both in transverse and longitudinal sections 



