PALEONTOLOGY OP ONTARIO. 133 



ridges or keels. In some cases, also, the inner ends of tlie keels are 

 connected together by an apjDarently continuous calcareous membrane, 

 so that the inner surface of the frond is completely closed. The cells 

 are carried in alternating double rows upon the inner surface of each 

 branch, their mouths appearing to be situated at the bottom of the 

 grooves afore-mentioned, and at the base of the great keel which 

 springs from each branch internally. ISTo cells are carried on the 

 areas formed by the anastomosis of contiguous branches. 



I have only seen a single, very large, and well-preserved example 

 of this genus, which occurs in the Corniferous Limestone. I have 

 named it Carinopora Ilindei, in honour of Mr. George Jennings 

 Hinde, by whom it was discovered, and who placed it in my hands 

 for examination. 



3. Taeniopora, gen. nov. — -Polyzoary calcareous, composed of a 

 flattened linear expan^sion, which branches dichotomously and is 

 celluliferous on both sides. Each side of the polyzoary is furnished 

 with a strong median ridge or keel, which has a longitudinal direc- 

 tion, and separates the frond into two lateral halves. The cells have 

 prominent mouths, and are arranged in from three to five longitudinal 

 rows on each side of the central keel, the cells of contiguous rows 

 alternating in such a manner as to produce a series of short, oblique 

 rows of cells, which diverge from the keel like the barbs of a feather. 

 The margins of the polozoary are usually plain and non-celluliferous, 

 and the cells are not separated by longitudinal stria3 or elevated 

 ridges. No fenestrules are present, and the entire frond forms a 

 continuoiis expansion, within which the cells are immersed. 



Taeniopora is distinguished from Ptilodictya by wanting the 

 laminar axis of the latter, by the possession of a longitudinal mesial 

 keel on each side, by having prominent cell-mouths, and by not 

 having the cells arranged in rows enclosed by elevated longitudinal 

 strise. 



Two species of the genus, T. exigua and T. penniformis, have come 

 under my notice as occurring in the Hamilton Rocks of "Western 

 Ontario. 



4. BoTRYLLOPORA, gen. nov. — Polyzoary calcareous, sessile and 

 encrusting, forming systems of small circular discs, which, though 

 social, are not organically connected or confluent. The upper sur- 

 faces of the discs are marked with prominent radiating ridges, which 

 carry the cells. Each disc is attached by its entire lower surface, 



