PROBLEM OF THE MONTICULIPOROIDEA I 71 



Septopora, etc., but only superficially. The Cerioporidae {op. at., 

 p. 266) most resembling Trepostomata have porous walls and 

 are in the second place not well determined. If viewed as 

 derived from Trepostomata the walls being assumed as having 

 become porous — an admissible hypothesis — this hypothesis 

 requires a reverse view of the evolution of Cyclostomata from 

 the first one, i. e., that the long tabulated cell, not the short open 

 one, is the more primitive in Bryozoa. 



The same differences disunite Chilostomata as Cyclostomata 

 from the Monticuliporoidea, where also their outward appearance 

 is similar, as for example Retopora {op. at., p. 289) and Septopora. 



The greatest importance rests on the interpretation of the 

 zooid's position with reference to the cell. In Bryozoa the 

 zooid inhabits closely the cell. In order to refer Monticuli- 

 poroidea to Bryozoa it appears essential that the zooid be con- 

 sidered as occupying the cell and Vine has so interpreted in his 

 definition of Cryptostomata, as said. In cells without tabulae of 

 some species the interpretation might appear logical {e. g., Ptilo- 

 dictya, except on the stem) but other species have tabulae {e. g., 

 Phylloporina) , whence the interpretation of superimposition of 

 zocecia and of zooids. This interpretation then unfortunately 

 assumes that which most requires proof. If there is anything 

 clear in Monticuliporoidea it is that the cell is the unit structur- 

 ally in every zoarium, that loculi between successive tabulae can 

 not be coordinated as such units because of inconstancy alone. 

 They vary in length and breadth ratio from 1 X 10 to 10 X I and 

 more, in the same zoarium. The interpretation of loculi as 

 zocecia precludes all uniformity of size and shape of zocecium. 

 In fact, the loculi are not described as structurally units in any 

 species — but the cell. In the definition of orders only the suc- 

 cessive loculi have been called zocecia, an interpretation that is 

 simply not supported by any evidence from the zoarial structure. 



Interpreting the cell, not its loculi, as the zocecium a great 

 difference is at once evident between Bryozoa (text Fig. 2, C) 

 and Cryptostomasa (Fig. 2, D) and Monticuliporoidea in general 

 in the position of the zooid — a matter of greater importance 



