Plate 16. 
Fig. 1 . Trypostcga venusta Norman, 1S64. (p. 95.) 
A Miocene example of this widely distributed species, X 20. 
Miocene (Duplin marl): Wilmington, North Carolina. 
Fig. 2. Lacerna mucronata Smitt, 1872. (p. 99.) 
A fossil, incrusting example X 20, referred to this recent species. 
Miocene (Duplin marl): Wilmington, North Carolina. 
Fig. 3. Arthropoma cornuta, new species, (p. 97.) 
The incrusting zoarium, X 20, showing the characteristic sinus and the frontal protuberance. 
Miocene ((hoctawhatchee marl): Jackson Bluff, Ocklocknee River, 25 miles southwest of Talla¬ 
hassee, Florida. 
Figs. 4-9. Stephanosella biaperta Michelin, 1842. (p. 99.) 
4. The incrusting zoarium, X 20, illustrating the triangular avicularia. 
5. A zoarium, X 20, with more rounded avicularia. The tremocyst is detachable from the sub¬ 
jacent olocyst. 
6. Interior of the zooecia X 20, illustrating the form of the apertura. 
Pleistocene: Rustic Canyon, Santa Monica, California. 
i. An example, X 20, containing both round and triangular avicularia. 
Pleistocene: Los Angeles, California. 
8. Surface, X 20, showing several ovicelled zooecia. 
Pleistocene: Vero, Florida. 
9. A zoarium X 20 showing the ancestrular zooecia and the thinness of the zooecial walls. The 
dietellae are very narrow. 
Pleistocene: Dead Man’s Island off San Pedro, California. 
Fig. 10. Schizoporella cumulata Ulrich and Bassler, 1904. (p. 96.) 
^ iew of the type specimen, X 20, showing the ii*regular arrangement and the piling up of the 
zooecia. 
Miocene (Choptank formation): Jones Wharf, Maryland. 
Figs. 11-15. Sckizopodrella florxdina Osburn, 1914. (p. 106.) 
11. A zoarium, natural size, composed of many lamellae. 
12. Non oriented ancestrular zooecia, X 20. 
13. Normal aspect of the zooecia, X 20. One zooecium has been regenerated with an avicularium 
occupying the apertura. 
14. A transverse section through a multilamellar zoarium, X 20. 
Miocene (Choctawhatchee marl): Jackson Bluff, Ocklocknee River, 25 miles southwest of Talla¬ 
hassee, Florida. 
15. Zooecia X 20, showing the form of the apertura more clearly. Several of the apertures are 
closed. 
Miocene (Duplin marl): Wilmington, North Carolina. 
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