Plate 39. 
Figs. 1-7. Phidolopora pacifica Robertson 1908. (p. 154.) 
1. Zoarial fragments, natural size. 
2. Celluliferous side of fragment, X 20, with the frontal avicularium well developed. 
3. Another fragment, X 20, in which the frontal avicularium is absent or worn away. 
4. Tangential thin section of the dorsal, X 25, illustrating the special calcification of the vibices. 
5. View of the interior of the zooecia, X 20. ap, apertura; pic, peristomie; d, dietellae. 
6. Dorsal side of zoarium, X 20, showing some radicular pores and an avicularium. 
7. Transverse thin section, X 25. 
Pleistocene: Rustic Canyon, Santa Monica, California. 
Figs. 8, 9. Phylactella spinosissima, var. major Hincks, 1884. (p. 170.) 
8. Zooecia of the incrusting zoarium, X 20, showing the recumbent ovicell. 
9. A specimen, X 20, with zooecia exhibiting the spines, oral mucro, and the tremopores. 
Pleistocene: Long Wharf Canyon, Santa Monica, California. 
Figs. 10-12. Costazzia robertsoniae, new species, (p. 181.) 
10. Zoaria, natural size. 
11. Surface of the globular zoarium, X 20, with ovicelled zooecia and interzooecial avicularia. 
12. Another surface, X 20, showing incomplete zooecia. 
Pleistocene: Rustic Canyon, Santa Monica, California. 
Figs. 13-17. Phidolopora labiata Gabb and Horn, 1862. (p. 154.) 
13. The reticulated zoarium, natural size. 
14. Celluliferous surface, X20, showing zooecia with large salient avicularia. 
15. A fragment, X 20, with ovicelled zooecia. 
16. Dorsal side of a fragment, X 20, illustrating the irregular vibices. 
17. Another fragment, X 20, with the zooecia distinctly outlined by a salient thread. 
Pleistocene: Santa Barbara, California. 
283 
