ART. 21 CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 93 



The longitudinal section is that characteristic of the Corymbopori- 

 dae as Canii has figured in 1919. The walls of the tubes are monili- 

 form. The gemmation is incomprehensible and the nature of the 

 pores remains still doubtful. Gregory's hypothesis is not clear. "The 

 pores seem to be due to the nearly complete filling of the aperture 

 of the dead zoaria by epizoarial material." 



In transverse section the tubes are polygonal, with adjacent walls; 

 they are larger at the zoarial center. 



Occurrence. — Lower Cretaceous (Valangian) : Sainte-Croix, Switzer- 

 land. 



Plesioty pes. —Cat. No. 69948, U.S.N.M. 



CORYMBOPORA (7) CUPULA D'Orbigny, 1853 



Plate 8, figs. 1-7 



1853. Reptomulticava cupula D'Orbigny, Pal^ontologie frangaise, Terrain Cre- 

 tac4, vol. 5, p. 1037, pi. 792, figs. 6-11. 



Our determination is possibly incorrect, for D'Orbignj^'s figures 

 do not indicate smaller tubes at the center of the zoarium nor col- 

 onies so thick. We maintain our determination, however, because 

 specimens of D'Orbigny's species as figured by him have never been 

 rediscovered at Le Mans. 



Our specimens are capitate, simple or agglomerate. The ovicel 

 is that of the Corymboporidae, absolutely analogous with that o 

 the genotype figured by Canu. Exteriorily the zoarium appears to 

 be formed of superposed lamellae in which the tubes are much 

 smaller at the center and on the margin. This is an illusion result- 

 ing from the special mode of gemmation in Corymbopora. Thin 

 sections confirm this observation. 



Occurrence. — Cretaceous (Cenomanian) : Le Mans (Sarthe), France. 



Plesiotypes.—Csit. No. 69949, U.S.N.M. 



