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BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



cribrilifera Maplestone, 1900, it is large, oval, ribbed, with a central 

 keel, sessile on zooecia." (Maplestone). This ovicell appears to us 

 to be hyperstomial, closed by the operculum and almost of the same 

 nature as that of Monoporella. In Macropora cribrilifera the oper- 

 culum is calcareous (Maplestone). In Macropora crassatina "the 

 operculum is thick, membraneous, not chitinous, except at the border 

 and has two lateral projections directed toward the basal wall of the 

 zooecium, showing similarity in this respect, to Afembranipora and 

 Cellaria" (Waters). It therefore has resemblances to the ovicell of 



Fig. 41. — Genus Macropora MacGillivray, 1895 



A-D. Macropora centralis MacGillivray, 1895. A. Three zooecia, X23; va, 

 vestibular arch. B. The aperture of a special form of zooecium (avicularium(?)), 

 X40. C. An operculum with its surroundings, X40. D. A dietella, X40. 

 (A-D. After Levinsen, 1909.) 



E. Macropora crassatina Waters, 1887. Ovicelled zooecia. Fossil. (After 

 Waters, 1887.) 



F. Macropora cribrilifera Maplestone, 1900. Zooecia showing broken ovicell 

 indicating that it is hyperstomial. (After Maplestone, 1900.) 



Monoporella. Finally the form of the aperture is identical in the two 

 genera. 



In 1920 we introduced this genus into the Coscinopleuridae but 

 these new observations lead us to place it in the Aspidostomatidae with 

 the reservation that only the knowledge of the larva will permit the 

 definite classification. Macropora differs from Monoporella in the 

 absence of opesiules and peristomial spines. 



Genotype. — Macropora centralis MacGillivray, 1895. 



The known species are as follows: 



Macropora cribrilifera Maplestone, 1901 Miocene. 



Macropora centralis MacGillivray, 1895 Miocene and Recent. 



Macropora {Monoporella) crassatina Waters, 1882 Miocene and Recent. 



Macropora vincularioides , new species Miocene. 



Macropora (Eschara) clarkei Tenison- Woods, 1876 Miocene. 



Macropora aquiae Canu and Bassler, 1920 Eocene. 



Macropora multilamellosa Canu and Bassler, 1920 Eocene. 



Macropora (Homalostega) convexa Marsson, 1887 Cretaceous (Campanian). 



