90 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



particularly in the position of the ovicell which is placed above the 

 peristomes and not below them. 



Ceriocava D'Orbigny, 1852; &pirodausa D'Orbigny, 1852; Ha- 

 plooecia Gregory, 1896 ; and the new genera Grammecava and Ripi- 

 soecia are referred to the family. 



Genus CERIOCAVA D'Orbigny, 1852. 



1852. Ceriocava d'Okbigny, Paleoiitologie frangai.se, Terrain Cr§tace, vol. .^, 

 p. 1015. 



The gemmation is peripheral. The tubes are long, cylindrical in 

 their ascending portion, and rectilinear and much widened in their 

 terminal recurved portion. There is no peristome. There are dia- 

 phragms in the cylindrical portion and the walls are vesicular in 

 the outer widened portion of the tubes. 



Genotype. — Ceriocava {Millepora) corymhosa Lamouroux, 1821. 



Structure and aiflnities. — The form of the tubes in this genus is 

 quite unique ; it has not yet been observed in other genera and it has 

 long been extinct. Gregory, 1896, maintained that this genus is of 

 the same type as Entalophora. This is an error, as it differs in the 

 gemmation, which is peripheral (and not dorsal), in the cylindrical 

 tubes, in their greater length (and not regularly widened), and in 

 the presence of diaphragms. 



CERIOCAVA CORYMBOSA Lamouroux, 1821. 



Plate 14, figs. 1-8. 



1821. MiUepora corymhosa Lamouroux, Exposition methodique des genres 



de I'ordre des Polypiers, p. 87, pi. 83, figs. 8, 9. 

 1896. Ceriocava cm-ymhosa Gregory, Catalogue fossil bryozoa in the British 



Museum. Jurassic, p. 163, fig. 13 (Bibliography). 



Sti'ucture. — Our studies have been made on the form Cenopora 

 pustulosa Michelin, 1846, which is rather common in France. 



The ovicell is rather rare; it is not always completely developed, 

 but it occurs in the form of elongate vesicles. It has its own special 

 wall, which is never common with those of the zooecia ; this is the 

 rule in Rectangulata, but we are totally ignorant as to how this 

 calcification occurs. 



The transverse section embraces two parts. In the center the 

 tubes are of the same diameter and correspond to the cylindrical 

 tubes. The periphery corresponds to a longitudinal section in the 

 •recurved ^^ortion of tlie tubes ; this portion is widened and the walls 

 are vesicuki.' and striated in the interior. 



The longitudinal section shows the tubes divided in two portions. 

 They are cylindrical in their greater length, ascending and recti- 

 linear: the walls are thin and adjacent and there are diaphragms far 



