14 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



by the development of lateral squamae analogous to the vertical rows of 

 leaflets in other species of Favosites. Pores numerous." 



This species differs from F. nitella, Winchell only in its mode of 

 growth ; in F. clausa the corallum is dendroid, in F. nitella it is gen- 

 erally discoidal, but sometimes digitato-ramose. In the original de- 

 scription* of the latter species it is said to occur in " small masses varying 

 from globoid to elongate or scarcely branching." 



Whether F. clausa is really distinct from F. nitella is a question 

 which can only be solved by the study of a large series of specimens 

 showing the variation in form of the corallum in both species ; such a 

 series is not at present available to the writer. 



The specimens in the collection of the survey are from the Hamilton 

 formation of Ontario, at Thedford and vicinity, in the township of Bosan- 

 quet, and from the Aux Sable River ; and from the Corniferous at 

 Cayuga, Ont. 



Favosites radiciformis, Rominger. 



Favosites radiciformis, Rominger. 1876. Geol. Sur. Mich., Fossil Corals, p. 33, pi. 

 XII., figs. 1, 2. 



" Cylindrical and apparently procumbent creeping stems of variable 

 thickness, from the diameter of a finger to that of a man's wrist, and often 

 several feet in length, with anastomosing or straddling branches. Tubes 

 of two sizes — the larger ones circular, from one to one and a half milli- 

 meter wide, the smaller ones angular, filling the interstitial spaces between 

 the larger tubes. Walls stout. Diaphragms rarely regular, straight, 

 usually complicated with the rows of lateral squamae." " Pores large and 

 moderately numerous. The terminal parts of the stems are always formed 

 of comparatively thin- walled, regularly formed tube orifices. On the 

 lateral faces of the stems, the orifices are often considerably narrowed and 

 disfigured by incrassation of the tube walls, while the lateral pore chan- 

 nels retain their usual diameter, and become transformed into long 

 vermicular ducts of nearly equal size with the principal tube channels. 

 Such specimens are very unlike, in external appearance, those with nor- 

 mally formed tube orifices." . > 



With this species are identified a few fragmentary specimens from the 

 Corniferous limestone near Woodstock, Ont., collected by Alexander 

 Murray in 1860, and two fragments from rocks of the same age at Long 

 Portage, Missinaibi River to Moose Factory, R. Bell, 1877. In one of 

 the specimens from Woodstock the openings of the corallites are very 



*Winchell. 1886. Rep. Lower Penins. of Michigan, p. 89. 



