94 BULLETIN 16 5, UNITED STATES NATIONAL MUSEUM 



Figures 3,4. Alderina rustica D'Ofbigny, 1852 (p. 20). 



3, Young ovicelled zooecia of the encrusting zoarium. From 

 Noxontown Millpond, Del. 



4, Portion of an ovicelled example with large zooecia. The 

 ovicell is hyperstomial and longitudinally carinated. 



5-9. Stamenocella oculata Ulrich and Bassler, 1907 (p. 21). 



5, A subcylindrical segment preserving the zooecium of the basal 

 articulation, the radicelled zooecia, and those of the normal 

 form. 



6, Flabellate bilamellate segment composed entirely of radicular 

 zooecia. From near Blackwoodstown, N.J. 



7, Segment exhibiting the basal zooecium of articulation, radi- 

 celled and normal zooecia. From near Blackwoodstown, N.J. 



8, An example showing the structure of the radicelled zooecia. 

 There is one regenerated zooecium. 



9, A flabellate segment showing the very salient lateral avicu- 

 laria. From near Blackwoodstown, N.J. 



Plate 4 



Figures 1, 2. Alderina welleri, new species (p. 21). 



1, Portion of the encrusting zoarium, showing several broken 

 ovicells, two regenerated zooecia, and an inverted giant one. 



2, Portion of an ovicelled example. From Noxontown Millpond, 

 Del. 



3-5. Allantopora annuloidea Ulrich and Bassler, 1907 (p. 25). 



3, Portion of the encrusting zoarium with zooecia, showing the 

 gymnocyst. 



4, Part of a colony with regenerated zooecia. The structure 

 of the ovicell is visible. 



5, An example showing the ancestrula, a small ordinary 

 zooecium. 



6. Allantopora irregularis Gabb and Horn, 1860 (p. 24). 



View of the uniserial, ramified, encrusting zoarium, with several 

 ovicelled zooecia. 



Plate 5 



Figures 1-3. Periporosella (?) pleoeia Gabb and Horn, 1862 (p. 25). 



1, Portion of the encrusting zoarium in which the ovicells re- 

 place the avicularia. Regenerated zooecia are present, and 

 the lateral dietellae are visible. From Noxontown Millpond, 



Del. 



2, An example with small interzooecial avicularia and some 

 zooecia with gymnocyst. 



3, The central portion of a zoarium, showing the ancestrula and 

 surrounding zooecia. 



4-7. Crassimarginatella intermedia, new species (p. 27). 



4, Surface of the encrusting zoarium, illustrating the large 

 interzooecial avicularia and ovicelled zooecia and containing 

 many regenerated zooecia. 



5, Surface with irregular zooecia and some regenerated ones 

 and (at the base to the right) zooecia inverted without appar- 

 ent cause. 



