20 



specimens of the latter exhibit only from three to five of the curved tabulae of the outer area 

 in the space of an inch ; whereas examples of B. approximalum present no less than from 

 ten to fourteen tabular in the same space. Whether this character is one of specific value or 

 not, may be questioned ; but I think it advisable to refer provisionally the specimens which 

 exhibit it, to a new species. 



Locality and Formation. Corniferous Limestone of Port Colborne. 



Genus CLISIOPHYLLUM (Dana). 



The genus Clisiophyttum is in an unsatisfactory condition, different palaeontologists hav- 

 ing included under this head Cyathophylloid corals which exhibit considerable differences in 

 structure. This will be evident, if we compare together the definitions of the genus given by 

 three distinguished authorities. Milne Edwards and Jules Haime define the genus as follows: 

 " Corallum simple, turbinate. Septa well developed, and rising towards the centre of the 

 calicu so as to form a spurious columella, but not twisted." 



Prof. McCoy defines Clisiophyllum as follows: " Corallum simple, branched or aggregate, 

 with vertical radiating lamellae ; a thin epitheca or outer wall ; internal structure (vertical 

 section), central area composed of small vesicular plates and cells converging or arching 

 upwards towards the centre, so as to form a conical boss in the cup ; no distinct central axis ; 

 outer area of small cellular structure, inclining in the opposite direction or upwards and out- 

 wards, separation between these areas formed by an intermediate area of larger, nearly hori- 

 zontal, cellular structure ; (horizontal section) a large central area of small irregular cellular 

 texture, i'rom which the primary lamellae radiate to the outer walls, intermediate zone with 

 few vesicular plates between the lamellae ; outer zone having the primary and secondary 

 lamellae connected by very numerous vesicular plates." 



According to Mr. Billings, lastly, the corals of the genus Clisiophyllum "have the same 

 general external form as those of the genus Zaphrentis, and their internal structure is also the 

 same, except that the transverse diaphragms are elevated in the centre so as to form a small 

 conical protuberance in the bottom of the cup, and, further, they are enveloped in an outer 

 area composed of vesicular tissue. The septal fossette is small, and in worn specimens its 

 place is often indicated by the prominence of one of the septa on the outside, which, being 

 stronger than the others, forms a longitudinal angular ridge. The cells of the tissue which 

 fills the outer area, slope upwards and outwards." 



It will thus be seen that high authorities differ widely as to the structure of the corals 

 which compose the genus Clisiophyllum. The most prominent distinguishing character of 

 the genus is admitted to be the presence of a conical boss or projection at the bottom of the 

 calice ; but there are grave discrepancies of statement as to the manner in which this projec- 

 tion is formed. According to i\iilne Edwards and Haime the boss is formed by the rising of 

 the septa of the coral towards the centre so as to constitute a spurious lamellar columella 

 the tabulae being comparatively poorly developed, and the: genus being thus widely removed 

 from Zaphrentis. According to McCoy, again, there are no central tabulae, in the proper 

 sense of the term, and the central projection is formed by the elevation and convergence of the 

 cells of a central vesicular area this also removing the genus widely from Zaphrcatis. 

 Lastly, Mr. Billing < considers that the central boss is formed by the elevation of a series of 

 well-developed tabulae ; and he places the genus in the immediate neighbourhood of Zaphren- 

 tis, or considers, at any rate, that the two genera are very closely allied. 



The above discrepancies are so great that it seems probable that several forms, in reality 

 belonging to different genera have been relerred to Clisiophyllum. Without, however, pre- 

 tending to decide this point, I shall simply describe here the previously recorded Clisiophyllum 

 Oneidaense ( Billings), from the Coruit'erous Limestone of Ontario, together with a related but 

 undescribed form, merely remarking that neither appears referable to the genus Clisiophyllum 

 as defined by McCoy. 



9. CLISIOPHYLLUM ONEIDAENSE (Billings). 

 (Plate IV. Figs. 4, 5). 



Clisiophyllum Oneidaense (Billinss), Canadian Journal, New Series, Vol. iv, p. 128. 



Corallum simple, turbinate, cylindrical or cylindro-conic, often curved. Central area 

 occupied by strong transverse diaphragms or tabulae, which are more or less strongly elevated 



