12 Mr. IT. M. Bernard on the 



adaptation to a passing- phase in the life of each individual 

 coral. But it is only fair to say that the whole tendency of 

 recent works on corals has been to discover the invalidity 

 of the supposed division Tetracorallia. 



Into the interesting questions which this suggests as to the 

 value of the existing divisions of the corals, we cannot here 

 enter, but content ourselves with merely pointing out that 

 while probably all the very earliest corals fell over and, if 

 they bent up again, became Tetracorallia during the process, 

 it is possible that many, which later had learnt a different 

 method of acquiring stability, might easily be knocked over 

 and in their efforts to become vertical again might become 

 Tetracorallia by accident. 



(d) The falling over of theprototheca enables us to find an 

 origin for several groups which are usually regarded as corals, 

 but whose position is still a matter of uncertainty. It is quite 

 within the limits of probability that a certain number of these 

 overturned polyps in their small protothecas should remain 

 prone and bud in this position. One such case we know of 

 for certain (seep. 28, on Heliolites). We ask whether the 

 creeping branching stocks of Auhpora might not also have 

 been formed by the early budding of a parent whose proto- 

 theca had fallen over. 



From Auhpora the genus Syringcpora might be deduced. 

 Syringopora is said to begin with the same horizontal creeping 

 stock as Auhpora, and then to bend up and form its tufts of 

 wavy tubes freely communicating with and supporting one 

 another. In these erect tubes very irregular tabular are formed 

 by the constant rising of the polyp in the tube as the latter 

 lengthens. The very presence of tabulae and of the rudi- 

 mentary septa, consisting of rows of points, clearly indicates 

 an affinity with early Madreporaria. Add to these the proto- 

 thecal outer covering, and we have the same three structures 

 which make up an Alveopora or a Favosites. It is only their 

 dispositions and the relative developments of the parts which 

 differ * 



Halysites could also be deduced from such a prone theca by 

 raj id continuous budding, in such a way that the parent and 

 its buds bent up in rapid succession into the vertical, as 

 shown in the diagram fig. 7, each then continuing to grow as 

 a thin flattened tube. These in contact and mutually sup- 

 porting one another would supply the typical skeleton of this 



* The apparent affinity between Syringopora and Favosites has been 

 pointed out by Mr. Bourne (Phil. Trans, vol. 18G b, p. 474). But Far 

 j.- structurally indistinguishable from Alveopora, and was not therefore an 

 Alcvonarian (Proc. Linn. Soc, Zool. vol. xxvi. (1898) p. 495. 



