62 



"HI 



layers, superimposed one upon the other. Corallites very minute, tubular, their circular cali- 

 ces slightly elevated above the general surface, and surrounded by a prominent margin, 

 From three to five calices in the space of one line, separated by intervals of from half to two- 

 thirds of their own width. Corallites, sometimes with the theca undivided, but more com- 

 monly partitioned off by a few remotely placed horizontal tabulae. Coenenchyma composed 

 of exceedingly minute tubuli, which are partitioned off by numerous close-set horizontal diaph- 

 ragms. No traces of septa. The surface exhibits at intervals of about two lines elongated, 

 star-shaped spaces, sometimes smooth, sometimes punctate or minutely pitted, which are not 

 penetrated by tubes of any kind, and appear to be quite solid. There are generally from three 

 to six corallites surrounding these vacant spaces, which are larger than the others ; and the 

 spaces themselves have a long diameter of about a line or more, by a shorter diameter of half 

 a line. In some specimens, also, the surface exhibits occasional large conical elevations pierced 

 each by a single canal, the diameter of which is about a line, and which descends vertically 

 into the mass. 



The characters of Callopora incrassata are most remarkable, and I am not satisfied that 

 two closely related species have not been included under the above description. That we have 



to deal here with a Tabulate coral allied to 

 Fistulipora or Heliolites is sufficiently clear ; but 

 there are many anomalous points presented by 

 the fossil. The specimens which I have included 

 under this head occur in at least three forms. 

 Some of them form thin crusts upon Heliophyl- 

 lum Halli or Cystipliyllwn vesiculosum, them- 

 selves in turn supporting the tubes of Ortonia 

 or Spirorbis, or the creeping stolons of Aidopora. 

 Others form flattened or undulating expansions, 

 and others appear as irregular or hemispheric 

 masses, varying from an inch in diameter or 

 less, up to the size of a man's head, and com- 

 posed of numerous concentric layers. The 

 majority of examples exhibit the extraordinary 

 clear spaces on the surf ace, which areneither pene- 

 trated by the corallites nor by the tubuli of the 

 co3nenchyma. These spaces are usually elon- 

 Fig. is. gated, and often somewhat depressed below the 



Callopora incrassata, (jSicu,. a. A fragment, natural general surface, and prolongations extend from 



size. b. A portion of the surface ma^iified,showiDg the calices th a star _lik e manner. The Corallites in 

 and ccenenchymal tubuli. c. A portion of the surface less " . ... . . . 



highly magnified showing a vacant space surrounded by coral- their immediate neighbourhood are also Usually. 



fiamntiSp alseCti0n fafr ^ mentenIarged ' Fr mthe some or all, larger than the ordinary ones.' 

 Only a few specimens exhibit the large conical elevations perforated by large vertical canals ; 

 but in those that do, these structures appear to belong properly to the fossil, and not to be 

 extraneous. In other minor respects the fossils differ very considerably amangst themselves. 

 The specimens from the Corniferous Limestone are mostly of large size, the corallites are of 

 comparatively small size, the intervals ocupied by the coenenchyma are proportionately wider, 

 and the fact that the coenenchyma is composed of minute tubuli can not be determined. I feel, 

 however, pretty sure that these peculiarities are simply to be ascribed to the method in which 

 the specimens from this formation have been fossilised. In the specimens from the Hamilton 

 formation, again, the peculiar vacant spaces are not always recognisable, and appear to be cer- 

 tainly absent in some instances over areas of considerable extent. Most of the Hamilton 

 specimens show very clearly the tubular nature of the cosnenchyma, but there is a good deal 

 of difference as to the amount of coenenchyma. Some examples have the corallites separated 

 by intervals of nearly their own width, the interspaces being filled with circular or polygonal 

 tubules. Others, on the other hand, have the corallites nearly in contact, with but a single 

 row of exceedingly minute tubuli separating them. An epitheca, so far as I have seen, is-; 

 only occasionally present, and the flattened expansions often carry corallites on both sides. 



Locality and Formation. Corniferous Limestone of Port Colborne, and more abundantly 

 in the same formation at Hagersville. Common in the Hamilton formation at Widder, and 

 also at Bartlett's Mills, near Arkona, in the Townships of Bosanquet and South Williams. 





