54: MB. STANLEY SMITH ON [March I913. 



insufficient to justify this generic separation. He stated, [9] pp. 05 

 & 96, that 



'This species forms the type oP the genus Aulophyllum of MM. Milne- 

 Edwards and Haime, from the definite tubular boundary to the inner area or 

 axis ; this, however, is merely a question of degree, serving to distinguish a 

 well-marked species, but scarcely applicable as grounds of generic division ; 

 for this inner area or axis is more or less defined in all \jClisiophylla'\, and 

 different parts or ages of the same specimen show variation in this respect.' 



In his figure, however, M'Coy represents the 'boundary to the 

 inner area ' as being much thicker and more solid than it really is ; 

 while he shows the tissue within this wall as thin and crowded, 

 dome-like tabulae, and does not emphasize its true composite nature. 



In criticizing the statements and conclusions of the earlier 

 authors, it must not be forgotten that their researches were made 

 without the aid of thin sections. 



M'Coy's observation that the wall is a character common to all 

 members of his accepted genus Clisiophylhvm is correct, in so far 

 as the term merely defines the limit of the central column. His 

 objection to the generic separation of the species prolapsum, merely 

 upon the more pronounced nature of the boundary of the inner area, 

 is scientifically sound and reasonable. Were the division of Aulo- 

 phyllum from Clisiopliyllum solely dependent upon that feature, 

 his views regarding the generic identity of the two would be 

 unassailable. 



In addition to the accentuated boundary, the central portion of 

 Clisiopliyllum prolapsum exhibits other and more important dif- 

 ferences which distinguish it from the other species of the genus 

 described by M'Coy. It has no columella or mesial plate, 

 and the central tissue consists of small, irregular tabulte, concave 

 towards the calyx, surrounded by plates bent sharply towards the 

 proximal end of the corallum ; while in Clisiopliyllum proper, 

 simpler tabulae slope at a more gentle angle from the trabeculate 

 columella. The vertical lamellae of the central column are far 

 more numerous in Aulophyllum than in Clisiopliyllum and its allies. 

 Although the distinctive features of Aulophyllum separate it from 

 the latter, yet the possession of a distinct central column con- 

 taining lamellae, groups these into a well-marked sub-group of 

 the CyathophyllidaD — the Clisiophyllidae. 



Milne Edwards & Haime replied to M'Coy's criticism in a later 

 part of their monograph, maintaining that their reasons for generic 

 separation were valid. They described two species, Aulophyllum 

 fungites and A. boiverbanki, 1 the specific differences between these 

 being that the former had more numerous septa, and an inner wall 

 wider in proportion to the diameter of the corallum than the latter. 



Duncan & Thomson, in 1867 [10], expressed the opinion that 

 A. fungites and A. botverbanki could not remain in the genns 

 Aulophyllum as defined by the French authors, maintaining that 



1 A. bowerbcmki is described in Milne Edwards's & Hahne's monograph as 

 having been found in Ireland. The type-specimen preserved in the British 

 Museum is labelled ' Oswestry.' 



