is smooth, and is sufficiently thin to allow of the walls of the corallites to be distinctly traced 

 through it. In such cases, the mouth or calice of the corallites appears to be closed with a 

 kind of disc, which is sometimes level with the general surface, often depressed slightly below 

 it, and sometimes elevated in the form of a rounded boss. 



In a very large number of specimens, the epitheca has been more or less denuded over 

 parts where it originally existed. In such cases, it is mostly only the epitheca which has 

 been removed, and the corallites are left intact and uninjured, with their calices quite empty. 

 In other cases, the epitheca has been entirely decorticated, whilst the corallites may remain 

 uninjured, or may be more or less broken away towards their outer ends. Such specimens 

 can in general be readily recognized by the general shape of the colony f nd the peculiar char- 

 acters of the corallites. In other cases, lastly, the epitheca is sufficiently thick to render the 

 calices of the corallites below, obscure or invisible. In these instances, concentric lines' of 

 growth are usually exhibited by the epitheca, and these are sometimes developed into such 

 strong and irregular annulations as to simulate pretty closely the appearance of perfect speci- 

 mens of Clisiophyllum Oneidaense (Billings). 



The corallites radiate from the imaginary axis of the colony, either in straight lines or 

 curves ; and the size of the mass in the turbinate specimens increases rapidly by the inter- 

 stitial addition of fresh corallites. In shape the corallites are rounded, sub-prismatic, or, more 

 commonly, distinctly prismatic. In size they are by no means uniform, there being generally 

 a considerable, number of under-sized corallites intercalated amongst the nearly equal-sized 

 larger tubes. The larger corallites have most commonly a diameter of from a line to a tenth 

 of an inch, whilst the smaller cnes may be half a line or less in width. 



The tabulae are commonly complete, sometimes incomplete, and are about three or four 

 in the space of a line. 



The mural pores, so far as I have observed, are uniformly in single rows, placed on the 

 flat surfaces of the corallites, not surrounded by an elevated border, and of comparatively 

 large size. Their distance apart is most commonly about half a line, but is sometimes as 

 much as a line. 



The walls of the corallites are of unusual thickness, in the great majority of cases ; and 

 they are not undistinguishably fused with those of contiguous corallites. Hence the lines of 

 division between the walls of neighbouring tubes can be plainly seen in parts from which the 

 epitheca has been removed, or even through the epitheca when the latter is of no great thick- 

 ness. 



Completely decorticated specimens might very readily be referred to one of the two 

 groups of forms usually placed in F. basallica (Gold.) ; the group, namely, comprising forms 

 with prismatic corallites of small size, with but a single row of cells. Specimens, again, exhibit- 

 ing longitudinal sections, but not exhibiting the outer surface, would also, almost certainly, be 

 referred to F. basaltica. In the former case, the thickness of the walls of the corallites, and 

 their being generally quite distinct and not fused with one another, would usually suffice for 

 their determination. In the latter case, a positive determination would probably be impossi 

 ble, unless some portion of the outer surface could be observed. 



Locality and Formation. Common in the Corniferous Limestone of Ridgeway, Port 

 Colborne, and other localities in Western Ontario. Also in the Hamilton Formation of the 

 Township of Bosanquet. 



FAVOSITES POLYMORPHA (Goldfuss). 



(Plate VII. Fig. 7.) 



Calamopora polymorpha (Goldfuss), Petref. Germ. Plate XXVII. figs. 2b, 2c. 2d, 3b,Sc 

 cast, exclusis). 



Corallum sub-massive or dendroid, often dichotomously branched, or reticulated ; dia- 

 meter of branches varying from a little over a line to more than an inch. Corallites radiating 

 in all directions from an imaginary axis, nearly at right angles or obliquely, more or less con- 

 tracted internally and widening as they approach the surface. Diameter of corallites from half 

 to three-quarters of a line in branches of half an inch across, often with smaller ones interca- 

 lated. Calices in reality more or less polygonal, but often rendered circular by the thickening 

 of their walls. Mural pores in single series. 



