570 Notice of Memoirs — On the Genus Favosites. 



are twelve well-developed septa, but these are indeterminable in the 

 Canadian specimens. The author agrees with Mr. Billings in think- 

 ing that this species may turn out to be identical with F. GotMandica, 

 and in refusing to adopt the genus Emmonsia proposed for this 

 species by M.-Edw. and Haime. 



Locality and Formation — Common in the Corniferous Limestone of 

 Eidgv/ay, Port Colborne, and many other places in Western Ontario. 



V. Favosites turbinata, Billings. — " Corallum forming elongate 

 turbinate masses, sometimes two feet in length and six inches in 

 diameter, often curved at the base. Corallites nearly uniform in size, 

 usually somewhat less than a line in width ; transverse diaphragms 

 thin, flat, flexuous, complete or incomplete. Only one row of pores 

 has been observed. Whole surface, except the upper part, covered 

 with a strong epitheca, which closes the mouth of the cells." — 

 Billings. 



The form of the colony varies much, sometimes being merely an 

 irregularly curved mass, which looks like a large potato. 



The epitheca in most specimens is smooth and sufficiently thin to 

 allow of the form of the corallites being traced through it. In a 

 large number of specimens it has been denuded or decorticated. 



The corallites radiate from the imaginary axis of the colony either 

 in straight lines or curves, and in shape are rounded, subprismatic, 

 or more commonly distinctly prismatic. They are by no means 

 uniform in size, there being generally a considerable number of 

 undersized corallites intercalated amongst the nearly equal-sized 

 larger tubes. 



The mural pores, so far as the author has observed, are uniformly 

 in single rows, placed on the flat surfaces of the corallites, and from 

 half a line to a line apart. 



Locality arid Formation — Common in the Corniferous Limestone of 

 Eidgway, Port Colborne, and other localities in Western Ontario. 



VL Favosites polymorplia, Goldfuss. — Corallum dendroid, often 

 dichotomously branched, or reticulated ; diameter of branches vary- 

 ing from a little over a line to more than an inch. Corallites radiat- 

 ing 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-quarters of a 

 line in branches of half an inch across, often with smaller ones 

 intercalated. Calicos in reality polygonal, but usually rendered cir- 

 cular by the thickening of their walls. Mural pores in a single series. 



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

 that Prof. Nicholson intends to treat of them hereafter along with 

 the species of Alveolites, to which they present many superficial 

 resemblances. 



The above definition includes the typical forms of F. polymorpha, 

 but there are numerous examples which can be regarded either as 

 mere varieties of it or as belonging to another species altogether. 

 Such, for example, as F. cervicornis and F. dubia, De Blainville. 



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. — B. B. W. 



