50 DEVONIAN ROCKS OF WESTERN CANADA. 



■which the epitheca has been removed, or even through the epitheca 

 itself when the latter is of no great thickness. 



Completely decorticated specimens might very readily be referred 

 to one of the two groups of forms usually placed in F. basaltica, 

 Gold. — the group, namely, comprising forms with prismatic corallites 

 • of small size, with but a single row of pores. Specimens, again, 

 exhibiting longitudinal sections, but not exliibiting 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 anothei", would 

 usually suffice for their determination. In the latter case, a positive 

 determination woiild probably be impossible, unless some portion of 

 the outer surface could be observed. 



Locality and Formation. — Common in the Corniferotis Limestone 

 of Ridgeway, Port Colborne, and other localities in Western Ontario. , 



YI. Favosites polymorpha (Goldfuss). 



Corallum dendroid, often dichotomously branched, or reticulated ; 

 diameter 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, more or less contracted internally and 

 widening as they approach the surface. Diameter of corallites from 

 half to three qu.arters of a line in branches of half an inch across, 

 often with smaller ones intercalated. Calices in reality polygonal, 

 but usually rendered circular by thickening of then- walls. Mural 

 pores in a single series. 



The ramose species of Favosites are so variable in their characters, 

 that I propose to treat them separately, along with the species of 

 Alveolites, to which they present many superficial resemblances. The 

 definition above given would include the typical forms of F. poly- 

 Tuorpha, but numerous examples are to be met with which may be 

 regarded as being on the one hand mere varieties of Favosites poly- 

 morpha, or which may on the other hand be regarded as distinct 

 species. Such, for example, are the forms which have been referred 

 by De Blainville to the species F. cervicornis and F. duhia, and which 

 have been regarded with more or less doubt as distinct by subsequent 

 observers. Besides the above, the Devonian Rocks of Western 

 Ontario yield at any rate one ramose form of Favosites which appears 

 to be distinct from any as yet described. 



