R. G. Carnithers — A Revision of some Carboniferous Corals. 165 



JRemarhs. 



The synonymy given is a long one, but it should be remembered 

 that the species concerned were founded in days when modern 

 methods of investigation were lacking, and when calicinal characters, 

 so strikingly variable in this species, had to be largely depended upon. 



The conclusions above set forth were not reached without a detailed 

 investigation of the abundant material at hand. Several hundred 

 specimens of this species, procured from the type locality, Tournai, and 

 mostly in a fine state of preservation, have been examined, besides 

 numerous examples from the Bristol area, kindly communicated by 

 Dr. Vauffhan. 



Diagram F. 



Fig. 1. — Ideal section illustrating factors governing the appearance of the septa 

 in calices and in transverse sections of Caninia cornucopice, Mich. 

 Septa shaded. A shows progressive rapidity in retreat of the septa 

 from the tabular surfaces as the coral becomes more cylindrical. 

 B shows development of septa influenced by distance between tabulse 

 (i.e. by variable rate of growth). 



Figs. 2 and 3. — Vertical sections cut down the middle of the cardinal fossula (right- 

 hand side of figures) , showing depression of tabulae into the fossula 

 and appearance of marginal dissepiments in mature growth stages. 

 Epitheca repeated by rejuvenescence at top of Fig. 3. Tournai. 



Fig. 2.— Brit. Mus. Nat. Hist. R. 11,689. Fig. 3.— Geol. 

 Surv. E.G. 349. Both natural size. 



The synonymy, lengthy as it is, might, with some justification, 

 have been further extended. It is, however, very desirable, not only 

 for zonal purposes, but on general palseontological grounds, that the 

 limits of specific determination should be defined as clearly as 

 possible. A common standard in such matters is not perhaps attain- 

 able, but it is believed that a re-examination of the material will 

 confirm the assignation of such apparently diverse forms to the one 

 species. 



A suite of specimens, in various stages of growth, and in an 

 exceptionally fine state of preservation, is preserved at the British 

 Museum, while a more complete assemblage is in the possession of 

 the Geological Survev. Both collections were derived from Tournai. 



