NORTH AMERICAN EARLY TERTIARY BRYOZOA. 553 



FIG. 163. Anatomical structure of the family Adeonidae Jullien, 1903. 



A. Adeona grisea Lamouroux, 1S1G. Specimen natural size, with radicles and fenestrae. 

 (After MacGillivray, 1SSO.) 



B, C. Adeona append-icuJatu Busk, 1SS4. B. A zooecium with ascopore and avicularium, 

 X 50. C. Operculum and mandibles, X 50. (B, C after Busk, 1SS4.) 



D. Structure of zooecium and polypide of Adeona. (After Jullien, 1888.) 



av, avicularium ; c, compensatrix ; tl, dorsal ; f, frontal ; gt, tentacular sheath ; mi; retractor 

 muscles of the polypide; op, operculum ; p, polypide; psp, ascopore. 



E, F. Adeonella platalea Busk, 1S52. E. Section of a zooecium, X 250, showing a mass with 

 several bodies and a part of a bud (6) by the side, but not inclosed in the mass; pore tubes (p) 

 or tubulae full of dark cells; outer membrane or ectocyst (oin) of the zoarium ; operculum (op) 

 walls of the zooecium (if. c. ). This specimen is somewhat difficult to understand, as it has the 

 appearance of being reversed. (After Waters, 1912. ) F. Section, X So, showing the ovicellular 

 znoecium nearly filled by the embryo (emb), with an ovarium (ova) now proximal to the embryo. 

 (After Waters, 1913.) 



G, H, Adeonellopsis coscinoijhora Reuss, 1847. G. Interior, X 40, showing the ascopore, 

 parietal areolae, and aperture. (After Levinsen, 1909.) H. Longitudinal section, X 25. (After 

 Waters, 1889.) 



ap, aperture: asc, ascopore: r, avicularium; //;, lamina perforata ; pee, peristoiuice ; pi, 

 peristomie. 



