480 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Genotype. — Prattia glandulosa D'Archiac, 1847. (See pi. 93, figs. 



I, J). 



Range. — Eocene (Auversian). 



Family ORBITULIPORIDAE Canu and Bassler, 1923 



Diagnoses and illustrations of this family and its genera were given 

 in our work of 1923. Mamillopora Smitt, 1872, and Fedora Jullien, 

 1882, included in this family at that time are now referred to the 

 Mamilloporidae. With the elimination of these two genera the fol- 

 lowing definition is more exact. 



Hexapogona in which the colony bears a central or terminal pit. 

 The ovicell is hyperstomial and recumbent and always oriented 

 towards the pit although the proximal border of the aperture is 

 alwa} 7 s turned towards the periphery. 



Family CONESCHARELLINIDAE Levinsen, 1909 



The zooecia are prismatic, hexagonal and surmounted by two 

 hexagonal, attenuated or potential pyramids. The aperture has a 

 distal sinus and is accompanied by a proximal pore. The colonies 

 are free and floating. 



The known genera of this family are FlaJbellopora D'Orbigny, 1852, 

 Conescharellina D'Orbigny, 1852, Trochosodon Canu and Bassler, 1927, 

 and Zeuglopora Maplestone, 1909. The recent studies of Livingstone, 

 1926, shows that Bipora Whitelegge, 1887, is a synonym of Flabell- 

 opora D'Orbigny, 1852. 



Genus CONESCHARELLINA D'Orbigny, 1852 



The zoarium is conical. The zooecia are hexagonal and super- 

 posed. The aperture is placed on the distal wall; its sinus is distal 

 toward the growing periphery of the colony. The avicularia are small 

 and placed in the interzooecial angles. 



Genotype. — Conescharellina augustata D'Orbigny, 1852. 



Range. — Upper Eocene — Recent. 



Structure. — The structure of the zooecia is identical with that of 

 Flabellopora. They are also superposed, however their length in- 

 creases without ceasing and their walls are slightly curvilinear and 

 very thick. They are supported on a group of internal axial zooecia 

 deprived of polypides and of which the number is often very large. 



The ovicells have been observed in Conescharellina philippinensis 

 Busk, 1854, and figured by Maplestone, 1910, and in C. crassa Teni- 

 son-Wood, 1879, figured by Livingstone in 1924. These two species 

 with C. ampulla Maplestone, "would be conveniently associated in 

 a new genus" (Livingstone, 1924). All the other species are abso- 

 lutely deprived of them. Under the name of semilunar slits 



