96 BULLETIN" 16 5, UNITED STATES NATIONAL MUSEUM 



Figure 9. Mollia lacessitor, new species (p. 37). 



An entire colony (X 1 and X 20), encrusting a Serpula and show- 

 ing the somewhat trifoliate opesium with straight proximal 

 border. 

 10. Mollia parvicella, new species (p. 38). 



The encrusting zoarium with ovicells and illustrating the small 

 zooecial dimensions. From Noxontown Millpond, Del. 



Plate 8 



Figure 1. Monoporella (?) laticella, new species (p. 39). 



The encrusting zoarium showing the large wide zooecia and the 

 two opesiules, as well as the olocystal frontal. 

 2,3. Diacanthopora convexa, new species (p. 68). 



2, Surface of the encrusting zoarium, showing the ancestrula. 



3, Part of a zoarium, showing that the epicalcification is individual, 

 much thickens the distal peristome, and hides the spines. 



4. Micropora parva, new species (p. 35). 



Portion of an encrusting zoarium. The linear opesiules, small 

 zooecia, and triangular avicularium are shown. From Noxon- 

 town Millpond, Del. 



5. Micropora (?) pulchra Ulrich and Bassler, 1907 (p. 36). 



The type specimen, a free, narrow, bilamellar frond, showing the 

 zooecia without opesiules but with a polypidianlike lamella and 

 also the endozooecial ovicells. 



6. Micropora (?) cylindracea Ulrich and Bassler, 1907 (p. 36). 



The free cylindrical fragmentary type specimen. 



7. Rhagasostoma americarui, new species (p. 40). 



Portion of the encrusting zoarium with ancestrula. The primo- 

 serial fusiform onychocellarium is apparent. From Noxontown 

 Millpond, Del. 



8. Micropora ogivalina, new species (p. 35). 



Portion of the encrusting colony, illustrating the ogival form 

 of zooecia and the short linear opesiules. 



Plate 9 



Figures 1-6. Coscinopleura digitata Morton, 1834 (p. 42). 



1, Surface of the narrow bilamellar zoarium with ordinary and 

 ovicelled zooecia. From Noxontown Millpond, Del. 



2, Fragment showing the marginal vibracular zooecia. From 

 Noxontown Millpond, Del. 



3, Bilamellar specimen, showing the lateral kenozooecia of 

 reinforcement. 



4, Vibracula arranged at the bifurcation. 



5, An example (X 6) with zooecia transformed into keno- 

 zooecia reinforcing a bifurcation and the middle of the 

 branch. The transformation of zooecia into kenozooecia is 

 visible. 



6, Specimen (X 10) showing a branch reinforced in the mid- 

 dle by zooecia transformed into kenozooecia. 



7,8. Setosinella prolifica, new species (p. 41). 



Two portions of the same encrusting zoarium with ovicells 

 and ancestrula. The zooecial characters, the hyperstomial 

 ovicell, and the setiform avicularia are indicated. 



