Plate 51. 



Figs. l-o. llitilJOmcnclhi iniiictnta. new species (p. 389). 



1. The iucrustiug zoiuium, natural size, growing over a bryozoau. 



2. Surface of tUe same, X 20. The areolae and the spines ou the peristome are quite 



distinct. 



3. Portion of a zoarium inerusting a shell, X 20, showing ovicelled zooecia. 

 Lower JacUsonian (Moodys marl) : Jackson, Mississippi. 



Cat. No. G40S6, U.S.N.M. 

 Figs. 4. 5. HippomencUa tuierosa, new species (p. 301 1. 



4. "i. .Surface of the iucrustiug type-specimen, X 20. and the same, natural size. The 

 frontal tuberosities are plainly shown. 

 Jliddle Jacksonian (Castle Hayne limestone) : Wilmington, North Carolina. 

 Cat. No. C40S7, U.S.N.M. 

 Figs. G-9. HippomeneUa HguUita, new species (p. 390). 



6. The typical form of the inerusting zoarium, X 20. with a\iculariuin removed from 



the aperture, and quite pro.ieeting. 



7. Basal surface of zoarium, X 20. Some of the zooecia are smooth and others have 



a hydrostatic projection. 



8. Zoarium of the typical form with ovicelled zooecia. X 20. 



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

 Cat. No. 640SS, U.S.N.M. 



9. A well preserved example. X 20. The erect mucro and the characters of the ovicell 



are to be noted. This probably represents a variation with avieularia close to 

 the aperture. 

 Middle Jack.sonian: Near I.enuds Ferry, South Carolina. 

 Cat. No. 640S9, U.S.N.M. 

 Figs. 10-13. Hippomrnellu axwvlata. new species (p. 391). 



10. Small inerusting zoarium, natural size. 



11. Surface of the same, X 10. 



12. Portion of tigure 11, X 20, showing variation in form and elevation of the mucro. 



13. Another zoarium, X 20, with ovicelled zooecia. 



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

 Cat. No. 64090. U.S.N.M. 

 Figs. 14-19. HippomeneUa ci'assicollis, new species (p. 391). 



14. The inerusting zoarium, X 20. showing the normal aspect of the zooecia. 

 Vicksburgian (Marianna limestone) : Near Claiborne, Jlonroe County, .Alabama. 



Cat. No. 04091, U.S.N.M. 



15. Zooecia, X 20, without ovicells, and little calcified. The avieularia are small. 



Vicksburgian (Byram marl): Near Woodwards, Wayne County, Mississippi. 

 Cat. No. (54092, U.S.N.M. 



16. Zooecia, X 20, with the frontal strongly calcified but with the avieularia regularly 



placed and the peristomial spines quite visible. 

 Upper Jacksonian (Ocala limestone) : Alachua, Florida. 

 Cat. No. 64093, U.S.N.M. 



17. Portion of a zoarium. X 20, with Intense pleurocystal calcification. The avieularia 



are Irregularly placed. 

 IS. Zooecia, X 20, with costulate ovicells. 



19. A zoarium. X 20, in wliicli the :ivieularia arc of unequal prominence and are irregu- 

 larly arranged. 

 Vicksburgian (Marianna limestone) : Near Claiborne. Monroe County. Alaliama. 

 Cat. No. 64091, U.S.N.M. 

 52 



