Plate 4. 
Figs. 1, 2. Rhynchozoon vaughani Canu and Bassler, 1919. (See also pi. 2, fig. 22.) (p. 155.) 
1. The unilamellar zoarium, X 20, showing young condition in which the zooecia are distinct. 
2. Old condition of zoarium, X 20. The zooecia are indistinct and not oriented. 
Lower Miocene (Bowden horizon): Cercado de Mao, Santo Domingo. 
Figs. 3-12. Metrarabdotos colligation Canu and Bassler, 1919. (p. 162.) 
3-5. Different aspects of the base of the zoarium, X 6. 
6. Three fragments, natural size, preserving base. 
7. Portion of zoarial surface, X 20, with ovicells well preserved. 
8. Base of a zoarium, X 20, showing calcification and disappearance of the apertures. 
9. Broad zooecia, X 20, characteristic of the aged condition. 
10. Narrow zooecia, X 20, of youthful condition. 
11. Normal zooecia, X 20. 
12. Longitudinal section, X 20, exhibiting the interior of the zooecia. 
Lower Miocene (Bowden horizon): Cercado de Mao, Santo Domingo. 
Fig. 13. Palmicellaria cf. inermis Jullien, 1882. (p. 149.) 
The branching fragment referred doubtfully to this species, X 20. 
Lower Miocene (Bowden horizon): Santo Domingo. 
Fig. 14. Rhynchozoon curium , new species, (p. 156.) 
The unilamellar zoarium, X 20, illustrating the characteristic short zooecia. 
Lower Miocene (Bowden horizon): Santo Domingo. 
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