VINE: NOTES ON FOSSIL POLTZOA. 
383 
in species of Eeteropora. at all comparably with them. It is very 
certain that these secondary cells have a functional value, both in 
Monticutipora and also in Eeteropora, but what this may be we are 
not in a position to say. The discussion, however, of the whole 
subject would be a long" and tedious one, and I do not think that 
after the masterly way in which the question has been treated by 
Mr. Busk, Mr. A. W. Waters, and by Prof. Nicholson,* much can 
be added — that is really new — to the material already in our hands. 
The question, however, may be much more simplified if a doubt is 
cast upon the Polyzoal affinity of Heteropora ; for whatever may 
be said in its defence, there is still wanting that knowledge which 
can be derived from the study of the living animal only, and since 
species of Heteropora are recent as well as fossil, we may still hope 
that even this knowledge will be forthcoming. After carefully 
reviewing the whole of our present knowledge, Prof. Nicholson 
states (op. cit., p. 77), " Leaving Heteropora out of sight, there are 
no other forms of the Polyzoa to which Monticulipora makes such a 
near approach as to render any very close comparison necessary." 
In the Monticulipora the secondary openings are, I ha ve no 
doubt, young forms of " Corallites" in a primitive stage, which bud 
around the parent corallite ; but whether the whole of these were 
destined to arrive at maturity is a question I cannot decide. In all 
probability they would not ; but still, in the living state these may 
have been possessed of a Zooid similar in some respects to the Zooid 
in the older calice. In the figures of superficial or secondary 
calices which I have drawn (PI. XX., Fig. l,bSb^,b^.), there are some to 
which I wish to direct particular attention. It will' be seen in (b') 
that the interstitial " openings are very similar to the larger 
opening (Fig. la). These two openings — and they are characteristic 
of others — appear as if the walls were united ; the separation indi- 
cated by the arrow appears in the section as only more transparent — 
no wall line can be seen. Other interstitial openings have an 
altogether different character. Two of these are given (Fig. 1, b^, 
b^) Both have apparently perforated tabulae, but they cannot be 
put down as such. They are very rare in the corallum, and in all 
* Genus Monticulipora, pp. 62-78. 
