Plate 10. 



Figs. 1-17. Trocliopoia touci Lea, 1833 (p. 103). 

 1. A group of zoaria, natural size. 



2 A large flabelliform zoarium of normal zooecia, X 20 (fonna ihwlusi). 



3 A zoariuin originally flabelliform, becoming discoidal by the proliferation of the 



lateral rows X 20. The ancestrula engenders a flabelliform central portion. 



4. Portion of a specimen. X 20, in which the radial arrangement of the zooecia is 

 more developed. 



5 Half of a zoarium X 20. The ancestrula is immersed. Both radicular and normal 

 zooecia are developed. The ancestrula gives rise to radicular zooecia (forma 

 almina ) . 



6. Portion of a zoarium, X 20, exhibiting radicular zooecia only. 



7 A small zoarium, X 20, composed of normal zooecia. 



s! A small discoidal example, X 20. The ancestrula is visible and gives rise to normal 

 zooecia only. 



9 The inner concave face of a flabelliform zoarium, X 10. 

 m The inner face of a smaller specimen. X 10. still showing tie flabelliform arrange- 

 ment at the center. 

 11 Inner side, X 20, showing growth on a quartz fragment. 



12. Portion of inner face of zoarium, X 20, showing the superposition of the disks. 



13. Broken edge of a zoarium, X 5. ^ . j 



14. Portion of the same specimen, X 20, showing fibrous structure of zoarium and 



growth on a grain of sand. 



15. Vertical fracture, X 20. , . , j. , 



16. Inner face of a discoidal zoarium, X 20, illustrating the superposed zooecial disks. 

 17! A zoarium, X 20. The flabelliform portion is formed of vibracula. 



Claibomian (Gosport sand) : Claiborne. Alabama. 

 Cat. No. 63837, U.S.N.M. 



