288 TABULATE CORALS. 



certain Monticulipora pass through a " Fistulipora stage," and 

 the apparent conclusion therefrom that Fistulipora, M'Coy, is 

 only a temporary condition of Monticulipora, I think it may be 

 said that the point at issue is narrowed essentially to a ques- 

 tion of words ;. for I hope to show that in one sense the great 

 majority of the Monticulipor<z are truly Fistuliporce. That is 

 to say, I think it can be shown that the forms which M'Coy 

 included under the name Fistulipora, and which Hall has 

 subsequently termed Callopora^ are, at most, mere subgeneric 

 forms of Monticulipora. I shall show, namely, that the pos- 

 session of a dimorphic corallum is a common feature in all the 

 Monticidiporte properly so called, and that the Fistuliporce are 

 only peculiar in the fact that they exhibit a special develop- 

 ment of the smaller tubes of the corallum. If this be admitted, 

 it is clear that the passage of a given species of Monticidipora 

 through a " Fistulipora stage " is a matter of comparatively 

 small importance from a theoretical point of view. At the 

 same time, I shall endeavour to show that the forms .included 

 under the names of Fistulipora, M'Coy, and Callopora, Hall, 

 have a real existence, in so far that the characters which dis- 

 tinguish these types are not of a merely temporary and tran- 

 sient nature, but that they' exist in unquestionably adult 

 examples. 



As regards the zoological position of the Monticuliporid<z, 

 there has been of late, as is well known, a strong tendency on 

 the part of palaeontologists to remove them from the Coelenter- 

 ata, and to relegate them to the Polyzoa. Some of the grounds 

 upon which this step has been proposed merely concern the 

 general resemblance in external characters between the Mon- 

 ticuliporoids and certain of the Polyzoa (such as Heteropord) ; 

 and I have already expressed my opinion of the value of this 

 resemblance in speaking of the systematic position of Chcztetes, 

 Fischer. The only positive and direct evidence in favour of 

 the removal of the Monticuliporce to the Polyzoa is to be found 

 in the account of the development of the former as given by 

 Lindstrom, and I have given the reasons which prevent me 



