Plate 17. 



Figs. 1-14. Acanthioiiclla occioporosii, new species (p. 614). 



1. Fragments of the free bilamellar zoariuni, natural size. 



2. Surface, X 20, showing zooecia with a thick frontal and separated h.v .i ilisfinet 



thread-like ridge. Both oriented and cumulate zooecia are present. 



3. Another surface, X 20, showing that the lyrula is not on the peristomial avicularium. 



4. A fragment, X 20, with ovicelled zooecia, a few of which show the much branched 



spine on its porous area. 



5. Another fragment, X 20. The lyrula is developed on the peristominal avicularia. 



6. An interior, X 30, showing the olocystal fibers arranged radially about the lyrula. 



7. Young zooecia, X 20, with gibbose frontal. 



S. The usual aspect of the interior of the zooecia, X 20. 



d. Transverse fracture of zoarium, X 20, illustrating the concentric lamellar structure. 



10. Another iwrtion of the same zoarium shown in figure 2, X20. Cumulate zooecia 



are developed with gibbosities. 



11. Tangential thin section. X 20. 



12. Tangential section of three zooecia, X 100, passing through the frontal. The 



arrangement of the olocystal elements in radial fibers about the lyrula is apparent. 



13. Thin section, X 100, showing microscopic structure of zooeeial wall. 



14. Several zooecia of the same section, X 100. The apertura, lyrula and ovicells are 



shown. 

 Claibornian (Gosport sand) : Claiborne, Alabama. 

 Cat. No. C3861, T'.S,N.M. 

 Figs. 15,16. OniichoccUa gcorfiiaiia, new species (p. 2(M1). 



15. The incrusting zoarium, X 20. The cryptocyst of the zooecia is finely grauulose. 



16. Another small zoarium, X 20, showing slight variations. 



Lower Jacksonian : Three and one-half miles southeast of Shell Bluff post office, 

 Georgia. 



Cat. No. 63802. U.S.N.M. 

 18 



