CANADIAN PALEOZOIC CORALS. 121 



cup rim of from 25 to 50 mm. Epibheca complete, with longitudinal 

 septal furrows moderately distinct. Septa numbering from about sixty- 

 four to one hundred and thirty-six, alternately long and short, the prima- 

 ries reaching the centre and generally curved, the secondaries 2 or 3 mm. 

 in length sometimes apparently almost obsolete. Calyx averaging about 

 15 mm. in depth, with steep sides and a very slightly convex floor above 

 which the primary septa converge as sharp keels to the centre ; the free 

 edges of the septa on the sides of the calyx are denticulated. Tabulae 

 numerous, close-set, stretching across the visceral chamber, turned down 

 at the edge and flat at the centre. A septal fossette is present on the 

 convex curve. Laterally the septa are continuous vertically but toward 

 and at the centre they often become mere cari nations on the upper sur- 

 faces of the tabula 1 . 



This species in some respects resembles Streptelasma rusticum of the 

 Hudson River formation and more particularly the extreme forms of that 

 species that have been described under the name of Zaphrentis Canaden- 

 sis. Its Streptelasmoid affinities are indicated by a thickening of the 

 outer ends of the septa and by the strong development of the primary 

 septa which, however, often have their vertical continuity broken near the 

 centre by the tabulae. On the other hand there seems to be, with few 

 exceptions, an absence of the axial cellulose structure characteristic of 

 Streptelasma, true tabula? extending across the entire visceral chamber. 

 On the whole Z. Stokesi may be regarded as a species intermediate be- 

 tween the two genera Streptelasma and Zaphrentis, combining as it does 

 structural peculiarities suggestive of both genera. 



Dr. Rominger has expressed the opinion that a strict distinction of the 

 above genera is not possible and has placed Streptelasma with Zaphrentis 

 as a sub-generic form. 



Localities. — Cormorant Point, Anticosti, Que., division III. of the 

 Anticosti group, J. Richardson, 1856, South-west Point and the "Jum- 

 pers", Anticosti, division IV., J. Richardson 1856 and one mile south of 

 Junction Cliff, Anticosti, division I., T. C. Weston, 1865. Cabot's Head, 

 Georgian Bay, Lake Huron, R. Bell, 1859, north end of Lake Temis- 

 caming, Que., R. Bell, 1887, also Isle of Mann (Burnt Island), Lake 

 Teniiscaming, A. E. Barlow, 1893 ; Niagara formation. 



'&j 



Zaphrentis Shumardi, Milne-Edwards and Haime. (Sp.) 

 Plate VIII., figs. 3, 3a and 4. 



Cyathophi/Uum Shumardi, De Verneuil, MSS. 



ii u Milne-Edwards and Haime. 1851. Polyp. Foss. dea Terr. 



Palaeoz., p. 370, pi. 7, fig. 3. 



