Plate 20 



Page 



Fiu. 1. Tholopora viryulosa Gregory, 1909 63 



Zoarium, X12, formed of four superposed subcolonies. 

 Lower Cretaceous (Aptian) : Faringdon, England. 

 Fig. 2-5. liadiopora tuherculata'D'OT))\gny,\^'^*d 63 



2. Zoarium, natural size. 



3. Two subcolonies, X12, showing the large diameter of the 



tubes. 



4. A portion of the surface, X25. 



5. Base of a zoarium, X12, showing the fan-shaped 



arrangement of the tubes. 

 Lower Cretaceous (Aptianj : Faringdon, England. 



Figs. 6-8. Heteropora nummularia, new species 13 



G. Zoarium, natural size. 

 7, 8. Surface, X12 and X2o. 



Lower Cretaceous (Aptian): Faringdon, England. 



Figs. 9-11. MulticresciH parvipora, new species 14 



9. Two zoaria, natural size. 

 10, 11. Portion of the zoarial surface, X12 and X2.'5, showing 

 the small irregular o\-al visors. 

 Lower Cretaceous (Valangian) : Sainte-Croix, Switzer- 

 land. 



Figs. 12-1.5. Mullicrescis landrioti Michelin, 1841 15 



12, 13. Top and basal view of a large zoarium, natural 



size. 

 14, 15. Zoarial surface, X 12 and X25. 



Lower Cretaceous (Valangian) : Sainte-Croix, 

 Switzerland. 



113 



