26 FREDERICK IV. SARDESON 



cell development known as ccenenchymal gemmation occurs in 

 both, and they are not distinguished. 



But Trepostomata generally have monticules or maculae, which 

 Tabulata never have ; and therein is the one important distinction. 

 But this also argues their relationship, for the Tabulata, compris- 

 ing three divisions, can be held as the Paleozoic ancestors and 

 representatives of the Alcyonaria as to three of four divisions 

 respectively, the fourth having no known ancestor, unless the 

 Monticuliporoidea be so considered. 1 Among those of the fourth 

 division Re?iilla et al. show a budding and grouping of the 

 dimorphic zooids similar to or like that which must have 

 obtained in the monticulate Prasopora et al. The absence of 

 tabulate skeleton in Re?dlla would be explained as in the case of 

 other Alcyonaria, and need not be recounted here. The sup- 

 posed relation of Monticuliporoidea and Pennatulidae I formerly 

 considered as based on deduction and slight evidence, and the 

 explanation of monticules is corroborative. 



These same monticules and maculae, on the other hand, bind the 

 Monticuliporoidea together, i. e., Trepostomata to Cryptostomata. 

 In the preceding paragraphs the relation of Trepostomata to 

 Alcyonarian corals is discussed without the Cryptostomata, 

 but these would not change the argument as given if included. 

 They are generally supposed to be Bryozoa, and are important 

 to that side of the question which will be given later. There is 

 in fact no character in the Monticuliporoidea to separate them 

 from the Tabulata, corals. Their separation, if accomplished, 

 would rest upon stronger evidence binding them to undoubted 

 Bryozoa. 



EXPLANATION OF PLATE A 



Fig. i. Monotrypa magna Ulr., cell pattern. X 10. 



Fig. 2. Monotrypa magna Ulr., vertical section of cells. X 10. 



Fig. 3. Diplotrypa limitaris Ulr., cell pattern. X 10. 



Fig. 4. Diplotrypa limitaris Ulr., vertical section. X 10. 



Fig. 5. Callopora multitabulata Ulr., a small zoarium, natural size. 



1 Op. cit, p. 349. 



