PROBLEM OF THE MONTICULIPOROIDEA 1 67 



from called maculae in the former are represented by maculae in 

 the latter. Indeed, sharply defined peripheral region, short 

 cells, reduction of tabulae, hemiphrams, filled vesiculose or solid 

 mesopores, and solid maculae, so-called acanthopores, and 

 mesial lamina, lunarium, etc., are found in highly specialized 

 Trepostomata of the Fistuliporoid type. 



There is no character in Cryptostomata that distinguishes 

 them all from Trepostomata. The former comprises essentially 

 certain families of highly modified zoaria related to Fistuliporidae 

 of Trepostomata. They are not a single branch from these, but 

 three or more, as seen when examples like Pacliydictya, Rhomb o- 

 pora, and Pliylloporina are compared. The genera named are the 

 Cryptostomata, which are scarcely separable, if at all, from 

 Trepostomata, but are not related one to the other as closely as 

 to Trepostomata. They compare back to Cramophylla, Eridotrypa 

 and Stellipora. respectively, which belong to three different recog- 

 nized families of Trepostomata. They belong to more than 

 distinct families, to three divisions of Cryptostomata, the frondif- 

 erous, cylindrical, and reticulate respectively. The highest 

 differentiated Cryptostomata, also, for example, Ptilodictya and 

 Fenestella unite to not the same Trepostomata-like Cryptosto- 

 mata. The question should be rather on the propriety of divid- 

 ing the Monticuliporoidea at all than on the probability of 

 Cryptostomata and Trepostomata belonging to different phyla. 



As to the interpretation of the zoarium of Cryptostomata, 

 the entire skeleton, excepting the under side of the basal expan- 

 sion, was covered by some kind of cortex uniting the zooids, as 

 proved by deposits of superimposed laminae in intercellular 

 spaces, on solid margins, and on the reverse surfaces. The 

 zooids built and evacuated the cells, resting more upon than in 

 them at maturity, as proved by tabulae close to the aperture, by 

 closed-up autocells, as in the stem of bifoliate zoaria, and by 

 the building of skeleton exclusively at its outer surface. Subor- 

 dinated zooids, in some degree of development, were always 

 present, since mesopore spaces, distinct or filled, are always 

 present in the peripheral region. Solid maculae, solid zoarial 



