61 
— cre. pv ?vWNTN-CCTVTtTsTeTOn. eee 
and there are groups of corallites slightly larger than the ordinary ones, and separated. by 
intervals of about a line and a half. From four to five calices in the space of one line. 
This species is very closely allied to C'. Goldfussi (Edw. and H.), but is distinguished by 
the fact that the calices are markedly polygonal, instead of being circular or oval, and that 
they are sub-equal, with very a smaller ones interspersed amongst them, whereas, in the 
latter species, there are intercalated amongst the ordinary calices a number of exceedingly 
minute ones. From the well-known Chetetes tumidus of the Carboniferous rocks, again, the 
present species is distinguished by the polygonal shape of the calices, their thin walls, and 
their much larger size, the corallites of the former being thick-walled and nearly circular, and 
there being about eight of them in the space of a line. 
Locality and formation—Not uncommon in the Hamilton group, at Widder, Township 
of Bosanquet. 
72. CHHTETES QUADRANGULARIS (Nicholson). 
Chetetes quadrangularis (Nicholson), Geological Magazine, Feb., 1874. 
Corallum forming thin crusts of from one-tenth to one-sixth of a line in thickness 
Corallites sub-equal, with very thin walls, about eight in the space of one line, for the most 
part polygonal, but often quadrangular in shape. The surface is smooth, and destitute of 
eminences, nor are there groups of larger corallites regularly interspersed amongst the smaller 
ones. 
This species is found commonly encrusting He/io- 
phyllum Halli, and often forming expansions of con- 
siderable extent, but apparently never composed of 
more than one layer of corallites. Itis distinguished 
from C. tuberculatus (Edw. and H.) by the smaller 
size of the corallites, the absence of distinct eminen- 
ces or gibbosities of the surface (‘‘ mamelons,”) and 
the very commonly quadrangular form of the ealices. 
Locality and formation—Not uncommon in the 
Hig. TS: _ Hamilton group of Bartlett’s Mills, near Arkona, 
a. Portion of the crust of Cheetetes quadrangularis, 
(Nich.), growing upon Heliophyllum Halli, slightly Township of Bosanquet. 
enlarged ; b. a few cells of the same greatly enlarged. 
From the Hamilton group. . 
Genus CALLOPORA (Hall). 
Corallum compound, massive, encrusting, or ramose, the corallites minute, tubular, _ 
separated by a still more minutely tubular coenenchyma. ‘lhe ccenenchyma always rendered 
vesicular by transverse diaphragms, and the corallites also usually tabulate. Septa rudimen-_ 
tary or absent. 
The genus Callopora includes a number of corals, which range from the Upper Silurian 
(Niagara group) to the Devonian, and which, in some instances, have decidedly the aspect of 
Polyzoa. The affinities of the genus are, however, beyond all question, so far at any rate, as 
the species which have come under my observation are concerned. Cdllopora, beyond all 
doubt, is a genus of Tabulate corals, and finds its nearest allies in the genera /Heliolites and 
Fistulipora. - From the former of these, Callopora is separated by the absence of septa, and 
from the latter by the fact that the tubuli of the coenenchyma are regularly tabulate, whilst 
the corallites themselves have the theca either open, or partitioned off by few remote horizon- 
tal tabulee. 
One large species, which perhaps may subsequently be found to admit of subdivision 
into two, has occurred to me in the Corniferous Limestone and Hamilton Formation of Wes 
tern Ontario, and this is very clearly distinct from all previously recorded forms. 
73. CALLOPORA INCRASSATA (Nicholson), 
_ / 
Callopora incrassata (Nicholson), Geological Magazine, Jan., 1874. 
Corallum sometimes encrusting foreign bodies, sometimes forming large expansions, or 
sometimes constituting large hemispheric masses which are composed of numerous concentric 
