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 Cal vet, 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. 
A-E. Ceriopora globosa Michelin, 1846. A, B. Zoarium natural size. (After Michelin, 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, 1896.) 
F ,G. Ceriopora tuberosa Romer, 1839. F. Zoarium, X 2. G. Vertical section, X 10, showing 
vesicular wall. (After Gregory, 1909.) 
Genus CERIOPORA Goldfuss, 1827. 
1827. Ceriopora Goldfuss, Petrefacta Germaniae, Abbildungen und Beschreibungen der 
Petrefacten Deutschlands und der angrenzenden Lander, Diisseldorf, 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 . — T riassic-Mioc.ene. 
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. 
