678 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



membraneous ectocyst, the disappearance of which leaves a clear line as seen in 

 thin sections. The vesicles are formed by contractions of this ectocyst in front of 

 the communication pores. We know also, according to C'alvet. that in the general 

 cavity of each polypide a large group of leucocytes are placed in proximity to 

 each of these pores. 



Classification. We have adopted the classification of Gregory, 1909, be- 

 cause at present it is impossible to do otherwise. It is evident that many of our 

 species will have to be changed to other families, if, as we. suppose, the discovery of 

 their ovicell is possible. 



FIG. 220. Forma Ceriopora Goldfuss, 1827. 



A-E. Ceriopora glol>osa . Michelin, 1846. A, B. Zonriuin natural size. (After Mi chelin, 1846. ) 

 C. Portion of the surface, X 22. D. Longitudinal section through marginal zooecia, showing dia- 

 phragms, X 12. E. Transverse section through central zooecia, X 12. (C-E after Gregory, 189(3.) 



F ,G. Ceriopora tuberosa Romer, 1839. F. Zoarimn, X 2. G. Vertical section, X 10, sh.iwing 

 vesicular wall. (After Gregory, 1909.) 



Genus CERIOPORA Goldfuss, 1827. 



1827. Ceriopora GOLDFUSS, Petrefacta Germaniae, Abbililungen und Beschreibungen der 

 Petrefacten Deutschlands und der angrenzenden Lander, Dusseldorf, vol. 1, p. 33. 



The tubes are prismatic or subcylindrical. No mesopores. The diaphragms 

 are numerous and horizontal. The zoarium is massive or branched. 



Genotype. Ceriopora micropora Goldfuss, 1827. 



Range. Triassic-Miocene. 



The tubes are branched at all heights. Externally they are not all of the 

 same diameter; the smaller are not mesopores, but are rudimentary zooecia, which 

 are developed superiorly. Many successive polypides occupy, in fact, the same 

 tube. 



