20 Mr. H. M. Bernard on the 



lim of the prototbeca. The compact layer of septal nodules 

 on both the inner and outer surfaces of the calicles cause the 

 walls to look as if they might be perforated — as if the deep 

 depressions between adjacent nodules might run right through. • 

 Eut this they do not do. One of the chief puzzles of Calosti/Us ^ 

 has been how to explain the pendent tongues of epitheca ) 

 which hang down irregularly and at intervals round the \ 

 corallum and sometimes bend even slightly outwards. There i 

 can be only one explanation of them, and that is supplied us 

 as soon as we have unravelled the modifications of the proto- 

 tbeca and recognized that its rim was bent in tiie way shown 

 in this diagram. I repeat it was of importance to have this 

 point settled, for a Silurian Perforate was a difficulty which i 

 the British Museum Catalogue had now to dispose of one way 

 or the other. 



Turning from this to a somewhat kindred point which has too 

 long been waiting for solution, and which may be partly dealt ^ 

 with in this connexion : Mr. Quelch* has raised the question as 

 to whether the Palaeozoic Cyathophyllidse are not still surviving 

 in the form which he has called J/ose/eyo. It is quite true that 

 we have in both cases skeletons built up of the same elements, 

 and at first sight similarly disposed. It has already been 

 pointed out by Mr. Pace that some of the suggested resera-f 

 blances of Moseleya to a Cyathophyllum have no value, such! 

 as, for instance, the supposed tetrameral symmetry of Moseleya.l 

 But arguments based upon more or less similarity will not carry\ 

 us far. The relationship can only be proved or disproved by an ' 

 analysis of the principles on which the two corals are built. 

 It is not merely tlie fact that both have similar elements 

 somewhat similarly arranged, which is of importance, but the 

 principles of their respective arrangements. Now whichever 

 of the curves or series of curves of the rim of the prototheca 

 shall afterwards be decided upon as that which shall charac- 

 terize the genus Cyathophyllum, there is no question at all that 

 the special forms which Mr. Quelch relied upon (e.g. C. Stiitch- 

 huryi and C regium, at least as figured by Milne-Edwards 

 and Haime in the ^British Fossil Corals ') are of the pattern 

 13 d with the floors tabulate and the sloping sides vesicular. 

 Hence unless Moseleya csin show a somewhat similar arrange- 

 ment of tabulae or vesicles^ the relationship between the two 

 cannot be maintained. Now an examination of the available 

 specimens of Moseleya shows a principle of protothecal modi- 

 fication which, in some respects, resembles diagram 13/^; but 

 on closer analysis it appears to be nearer that other method 



* Chall. Report, xvi. 1886, p. 110. 



