Plate 50. 



Figs. 1-S. l/iiiii<iiii< ik Jhi iitcduililn. new sin'cios (|i. 383). 



1. Frasiiients of the free biliimellar zoariiini, natural size. 



2. A znariiim with long zooecia, X 20. Lateral avicularia are wanliiig. 



3. Short zooecia. X 20. 



4. Zooecia, X 20. with an aviculariau monstrosity developed. 

 a. Ovicelled zooecia. X 20. showing the nsnal asiiect. 



Middle Jacksonian: Rich Hill. Georgia. 

 Oat. No. eiOSO, U.S.X.JI. 

 0. Ovicelled zooecia. X 20. in which the two lateral primitive areas are visiljle. 

 Middle Jacksonian: 17 miles northeast of Hawkinsville, Georgia. 

 Cat. No. 64081, U.S.N.M. 



7. Ovicelled zooecia, X 20, with the nsnal irregular puuctations on the ovicells. 



8. Sketch of the interior of an apertnr.i. illnstrating the nnicronoid protuberance and 



the cardelles. 

 Middle Jack.sonian : Three and one-half miles north of Grovania, Georgia. 

 Cat. No. 64082, U.S.N.M. 

 Figs. !J-1S. HipponiencUa alifera, new species (p. 3S6). 



9. Small fragments of the unilamellar zoariura. natural size. 



10. Normal zooecia, X 20. in which the areolae are arranged in two or three rows and 



the avicularia are short and irregularly arranged. 



11. Normal and ovicelled zooecia. X 20. The frontal is almost covered with areolae, 



the ovicells are pyriform. and the avicularia are large and winglike. 



12. Zooecia, X 20. with globular o\icells mi which the two areas are well marked. 



18. Normal and ovicelled zooecia, X 20. 



14. Normal zooecia. X 20. in which the spines .-ind the aviculai'ian I'rotuberances are 



well developed. 



15. Smooth lower face of zoarium, X 20. 



16. Dorsal of zoarium, X 20. showing the two layers, olocyst (inner) and pleurocyst 



(outer). 



17. An example, X 20. in which large hydrostatic tuberosities occur. 



IS. View of the interior, X 20, showing the larger porta separated from the smaller vanna 

 by two cardelles. 

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

 Cat. No. 64083, U.S.N.M. 

 Figs. 10-24. lliiipoinencUa radirntn, new species (p. 3S7). 



19. The unilamellar zoarium. natural size, which has grown about an alga. 



20. Ovicelled zooecia, X 20. in which the two areas of the ovicell are replaced by 



punctations. 



21. Normal zooecia, X 20, with and without iiitcrareolar costules. 



22. Normal and ovicelled zooecia, X 20, with symmetrical avicularia. 



23. Lower face of zooecia. X 20, transversely striated and pierced by a pore. 

 Lower Jacksonian (Moodys marl) : Jackson, Mississijijii. 



Cat. No. 64084, U.S.N.M. 



24. Zoariura, X 20, showing zooecia with well-developed spines and vestibular arch. The 



single ovicell intact exhibits the two areas. This is the most usual aspect. 

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

 Cat. No. 64085, U.S.N.M. 



51 



