Plate 17. 
Figs. 1-12. Stylopoma spongites Pallas, 1766. (p. 102.) 
I, 2. Two forms of the zoarium, natural size, made up of many lamellae. 
3, 4. Transverse sections of zoaria, natural size. 
5. Surface X 20, showing broad unovicelled zooecia. 
6. Another surface X 20, exhibiting nonoriented zooecia which bear conspicuous avicularia. 
7. Inferior face of a lamella, X 20. 
Miocene (Duplin marl): Wilmington, North Carolina. 
8. Normal zooecia with avicularia X 20. Dietellae are not present. The broken ovicell shows 
the tremocyst resting on the olocyst. 
9. Normal and ovicelled zooecia X 20. The ovicell surrounds and conceals the apertura. 
10. Ancestrular portion of a zoarium, X 20. 
II. Zooecial walls X 20, obtained by abrasion of the surface, showing arrangement of the septules. 
12. A portion of a zoarium X 20, with quite elongated zooecia. 
Pliocene (Caloosahatchee marl): Shell Creek, De Soto County, Florida. 
Fids. 13, 14. Schizopodrella unicornis Johnston, 1847. (p. 105.) 
13. Photograph of a well-preserved Miocene specimen, X 20, showing the form of the apertura 
and the avicularia clearly. 
14. Zooecia of the type specimen of Schizoporella subquadrata Ulrich and Bassler, 1904, now con¬ 
sidered as a synonym of S. unicornis. 
Miocene (Choptank formation): Governor Run, Maryland. 
Figs. 15-17. Hippaliosina rostrigera Smitt, 1872. (p. 167.) 
15. Zooecia, X 20, of a form exhibiting only one avicularium above the aperture. 
Miocene (Duplin marl): 1 mile northeast Suffolk, Virginia. 
16. The normal form of the species, X 20, with two avicularia. 
17. Interior of zooecia, X 20, illustrating the two cardelles and the olocyst. 
Pliocene (Caloosahatchee marl): Monroe County, Florida. 
Figs. 18-19. Schizopodrella pusilla, new species, (p. 106.) 
18. The free bilamellar zoarium, natural size. 
19. Surface, X 20, showing the small zooecia with large tremopores. 
Miocene (Choctawhatchee marl): Jackson Bluff, Ocklocknee River, 25 miles southwest of Talla¬ 
hassee, Florida. 
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