514 Mr. H. M. Bernard on the 



sional adventitious budding, conforms to the type. And yet 

 these forms have been thought to represent a transition 

 between Turhinaria and Astrceopora, with their very different 

 method of budding and of growth. 



Relation of Turbinaria to Astrceopora. — If there is any 

 connexion between Turhinaria and Astrceopora, it is not by 

 way of their glomerate forms, for both genera have thin 

 creeping as well as solid hemispherical methods of growth. 

 Their affinity cannot be based upon the mere superficial 

 resemblance of certain specialized growths. As far as I am 

 at present in a position to compare them, it appears to me 

 that they have no immediate connexion. The budding of the 

 Turbinarians is probably one of the most specialized to be 

 found amongst Corals, and that of Astrceopora shows no resem- 

 blance to it. The polyp-cavities and the coenenchyma are far 

 simpler and more primitive in Astrceopora than they are in 

 Turhinaria. The costal, of which it is built up as one of its 

 chief elements, are in many cases simple echinulations, and 

 still show the primitive connexions with the septa, a con- 

 nexion which has apparently been secondarily lost in both 

 Madrepora and Turhinaria. Further, the pronounced colu- 

 mella of Turhinaria is not developed in Astrceopora, although 

 the elements out of which it might be formed are clearly 

 traceable. 



In view, then, of these much simpler conditions found in 

 Astrceopora than occur in either Madrepora or Turhinaria, 

 it seems to me to run counter to the most elementary 

 canons of morphology to deduce the Astrceopora from a special- 

 ized form of the specialized Turbinarians. Only the most rigid 

 demonstration of ontogenetic simplification in the case of the 

 former could justify such an order of descent. Failing such 

 a demonstration we have to place Astrceopora as the most 

 primitive of the Madreporidse, from which, first Madrepora, 

 and then Turhinaria, as I think, through Madrepora, may 

 have been deduced. In Madrepora the first stage is an 

 encrusting one, as, with some modifications, it always remains 

 in Astrceopora. The typical method of growth by means of 

 special axial polyps appears later. From such a specialized 

 method of growth the still more specialized type of the 

 Turbinarians can be deduced in the manner above described. 



However intelligible and satisfactory such an order of 

 descent may at first sight appear, it can only be accepted 

 provisionally, inasmuch as it is based upon the skeletal 

 structures alone. It can hardly be considered to be esta- 

 blished until the soft parts have been studied especially from 

 this point of view. Fowler has shown that differences 



