718 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Berenicea ingens. 



Berenicea benjamini. . 



Berenicea incondita. 



12. 



Berenicea palmula. 



13. 



Plagioccia divagans. 



14. 



Plagioecia concreta. 



15. 



Plngioeda clavioedes. 



Plagioccia brundidgensis. 



Plagioecia botula. 



Plagioecia Jiirta. 

 Plagioccia superposita. 

 Plagioecia concreta. 



fPeristome=0.18 mm., tubes horn-shaped 



11 1 Peristome=0.20 mm., tubes cylindrical 



iPeristome 0.16 mru 



iPeristoine smaller 



12 fZoarium palm-shaped, dichotomously branched and successive 



\Zoarium orbicular or irregular '. 



(The zone of growth is very thick; the tubes are grouped in rows on 

 13< the zoarial margins; P=0.10 mm 



I Zone of growth little thick or invisible 



j4/ Ovicell very long 



lOvicell short 



|Peristome=0.12 mm., tubes claviform 

 Peristome=0.08-0.10 mm., tubes bent upward at the extremity __ 

 Peristome=0.12-0.16 mm., tubes cylindrical 

 Peristome=0.10 mm., tubes horn-shaped, rectilinear, not bent up- 

 ward 



jgf Separation of the peristomes=0.44 mm 



I Separation of the peristomes=0.52 mm 



DESMEPLAGIOECIA, new genus. 



Plagioecia, in which the tubes are grouped in fascicles. 

 Genotype. Berenicea lineata MacGillivray, 1885. 

 Range. Turanian-Recent. 



This genus includes the genus Actinopora D'Orbigny, 1852, that is to say, the 

 assemblage of species with orbicular zoarium. It is necessary to classify in it also 



certain species of Reticulipora of the group 

 Reticulipora obliqua D'Orbigny, 1852. We 

 include in it also some species of the old 

 group of Reptotubigera; these are the in- 

 crusting dichotomous forms. We do not 

 think that the zoarial dichotomization cor- 

 responds to a special function. In spite of 

 the yery great exterior difference between 

 the zoarial forms Actinopora and Reptotu- 

 bigera, we class in the same genus all the 

 species in which the ovicell is identical and 

 which are provided with fascicles. This 

 ovicell is transverse and it interrupts or de- 

 ' o forms the fascicles just as in Plagioecia it 



FIG. 234. Desmeplagioecia, new genus. obstructs, separates, or deforms the isolated 

 A colony of Desmeplagioecia (Actinopora) , , r,,, n -j 4.1 f j u 



,. ' . "_ .. , ' tubes. The ovicell is evidently formed be- 



hneata MacGillivray, 1885, X 12, in which J 



the ovicells form an almost complete ring. fore the calcification of the neighboring 

 o, oeeiostome. (After Harmer, 1915.) tubes. 



The principal species hitherto described are; 



Desmeplagioecia (Berenicea} lineata MacGillivray, 1885. Recent. 



Desmeplagioecia (Pavotubigera} gambierensis Waters, 1884. Miocene. 



Desmeplagioecia (Pavotubigera} dimidiata Waters, 1884 (not Reuss, 1847). 

 Miocene. 



Desmeplagioecia (Semitubigera) doll/usi Canu, 1909. Lutetian. 



Desmeplagioecia (Actinopora} organisans D'Orbigny, 1851. Cretaceous. 



