78 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Membranipora villosa Hincks, 1880. 



Membranipora (Flustra) isdbelleana D'Orbigny. 1839. 



Membranipora pura Hincks, 1880. 



Membranipora (Flustra) tehuelcha D'Orbigny, 1839. 



Membranipora nitens Hincks, 1880. 



Membranipora hyadcsi Jullien, 1888. 



Genus HETEROOECIUM Hincks, 1892. 



1892. Heterooecium HINCKS, Contributions towards a General History of the Marine Polyzoa, 

 Appendix, Annals and Magazine Natural History, ser. 6, vol. 9, p. 312. 



The ovicell is acanthostegous. 



Genotype. Heterooecium amplectens Hincks. 1881. Eecent. 



st 



FIG. 19. Genus Meinlrunii>ora Blainville, 1834. 



A, B. Membranipora membranacea Linnaeus, 17oS. A. Ordinary zooecia, X 15. B. Abnormal 

 cells ("tower zooecia"), X 15. (After Hincks, 1SSO.) 



C. Cyphonautes occidentalis Robertson, 190S, the larval stage of Membranipora villosa 

 Hincks, 1880, X 70, showing the organism in optical section as it appears while still living and 

 lying on its side, a, apex; ab, aboral; add. mus., adductor muscle; ant, anterior; op. t, apical 

 tuft; d, denticle; fl, fiber; int, intestinal tract; m, mouth; O, oral; post, posterior; pyr, pyrifonn 

 body ; rb, rib ; re. d, retractile disk ; st. c, stiff cilia ; stm, stomach ; sue, sucker. 



Genus PYRIPORA D'Orbigny, 1852. 



1852. Pyripora D'ORBIGNY, Paleontologie francaise, Terrain Cretace, Bryozoaires, vol. 5, 

 p. 538. 



Colony fixed, creeping over the surface of other bodies, formed of little regular, 

 longitudinal and lateral lines of cells placed one after the other, not contiguous 

 laterally, and disposed in a manner to represent creeping branches more or less 

 extended. Cellules pyriform, narrow behind, and enlarged in front, open in dead 

 or fossil individuals over the greater part of their anterior portion. No special 

 pores, no accessory cells, nor ovarian vesicles. (After D'Orbigny, 1852.) The 

 operculum is calcified. (Levinsen, 1909.) 



