628 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



aperoecia takes precedence by its earlier appearance in Lamouroux's 

 work, but owing to the uncertainty as to its nature Berenicea had better 

 be discarded. 



Mesenteripora, genotype M. michelini Blainville, 1830:397, was pro- 

 posed for erect contorted forms otherwise similar to Diastopora. Here 

 again the genotype is a fossil without ovicells. 



Bidiastopora, genotype Diastopora cervicornis Michelin, 1846:241, 

 was founded to include erect diastoporas with bilaminate folds, and the 

 genotype is a fossil without ovicells. 



Actinopora, genotype A. regularis d'Orbigny, 1853:763, was based 

 on the arrangement of the zoids in regular radiating series and like the 

 preceding included only fossil species without ovicells. The ovicelled 

 species which have later been placed in this genus have the ovicells and 

 ooeciostomes definitely of the Plagioecia pattern. 



The above generic names were all properly founded but only on 

 zoarial characters, so their complete nature is uncertain. They may still 

 be useful when it is necessary to catalog specimens which are incomplete 

 in reproductive characters. 



In 1918 Canu attacked the problem of the old Diastopora complex 

 with the ovicells as the basis, and proposed a number of additional 

 genera, Microecia, Plagioecia, Diaperoecia and Diplosolen. 



Microecia Canu, 1918:326, was mistakenly founded on Diastopora 

 Sarniensis Norman, 1864:89, and is synonymous with Plagioecia. 



The other three genera agree in the mode of early development in 

 the tubuliporoid manner, in the closure of numerous older peristomes 

 by a calcified porous membrane, and by at least the occasional enclosure 

 of peristomes by the ovicell. 



Canu went so far as to propose several new families, Mecynoeciidae, 

 Plagioeciidae and Diaperoeciidae among the diastoporid forms. The first 

 of these, which included Microecia, has already been reduced to syn- 

 onymy by Bassler, 1935:10. While Canu's analysis of the ovicell is of 

 the greatest importance in the separation of species of this group, he 

 apparently was not sufficiently familiar with the intraspecific and inter- 

 specific variation in the ooecia and ooeciostomes. 



For the purpose of the present work I propose to accept only the old 

 family Diastoporidae with the following genera: 



1. Diastopora Lamouroux, 1821, reserved for species in which the 

 reproductive characters are unknown. 



