Plate 49. 



Figs. 1-3. Hippoporina hiporosa, new species (p. 377). 



1. Xoruial and ovicelled zooecia of the incrusting zoarium, X 20, showing shape of 



aperture and occurrence of the avicularia. 



2. Another portion of the same zoarium, X 20. 



3. The ancestrnla and surrounding zooecia, X 20. 



Middle Jaclvsonian (Castle Hayue limestone) : Wilmington, North Carolina. 

 Cat. Xo. 64076. TJ.S.N.M. 

 Figs. 4-14. HippnincnrUa ratiila, new siiecies (p. 3S1). 



4. Fragment of the bifoliate zoarium, X 20, preserving several monstrous zooecia similar 



to the cumulate zooecia of the Oelleporidae. 



5. Portion of a zoarium, X 20, with narrow zooecia, salient mucro and no avicularia. 



6. Another fragment. X 20. exhibiting avicularia and wide zooecia. 



7. Very large ovicelled zooecia, X 20. 



8. Ordinary and ovicelled zooecia, X 20, with avicularia. 



9. Ordinary zooecia wider than usual, X 20. 



10. Interior of the zooecia, X 20, showing the olocyst and tremocyst and the form of the 



aperture. 



11. Tangential thin section, X 2.5, through zooecia without avicularia. 



12. A tangenti.ll thin section, X 25. in which the mucro and the avicularia are visible. 



In this and the preceding figure the structure of the olocyst and tremocyst Is quite 

 plain. 



13. Tangential thin section of several zooecia, X 100. 



14. Three fragments of the bifoliate zoarium, natural size. 

 Lower Jacksonian (iloodys marl) : .Jackson, Mississippi. 



Cat. No. 64077, U.S.N.M. 

 Figs. 15-17. Ilippomenclla transvcrsnta. new species (p. 382). 



15. Fragmentary portion of the bilamellar zoarium, natural size. 



16. Ordinary zooecia, X 20, showing the decidedly transverse arrangement of the avicu- 



laria. 



17. Another zoarium, X 20, preserving several broken ovicells. 



Middle Jacksonian (Ca.stle Hayne limestone) : Wilmington, North Carolina. 

 Cat. No. 64078, U.S.N.M. 

 Figs. IS, 19. HippomeneUn (iiit/usfficilrs. new species (p. .3.S3). 



18. The narrow, free, bifoliate zoarium. natural size. 



19. Portion of the same specimen, X 20. There are four to six spines on the peristome. 

 Middle Jacksonian (Castle Hayne limestone) : Wilmington, North Carolina, 



Cat. No. 64079, TJ.S.N.M. 

 50 



