Plate 20 



Page 

 FiCis.l-H. Cigdisula serrulata Smitt, 1873 125 



1. Zoarial fragments, natural size. 



2. Surface of the free bilamellar zoarium: X 20. There 



is a small avicularium above each peristome. 



3. Young ovicelled branch, X 20, showing structure of 



the costulated ovicells. 



4. Another bi'anch, X 20, showing that the lateral zooecia 



do not have a frontal avicularium. 



5. An example, X 20, in which the axial zooecia bear a 



large spatulate frontal avicularium. 



6. An adult frond, X 20, illustrating structure of the 



ovicells. 



7. Frond, X 20, showing the great irregularity of the 



adventitious organs. 



8. An example, X 20, in which the lateral zooecia are 



transformed into large spatulate avicularia. 



9. A variation, X 20, with numerous and complicated 



pores. At the base of this zoarium there are normal 

 zooecia. 



10. Surface; X 20. All the zooecia bear a spiramen. 



The frontal pore opens in the peristomie. 



11. Basal part of a zoarium; X 6. The base is little 



expanded but is concave and prehensile. 



12. Interior of zooecia, X 20, showing the spiramen open- 



ing into the peristomie. 



13. Transverse section, X 25, showing the septules and 



the great thickness of the frontal walls. 



14. Longitudinal section; X 25. 



Fowey Light, 15 miles south of Miami, Fla. 



185 



