506 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 

 Genus TRIPHYLLOZOON Canu and Bassler, 1917. 



1917. Triphylloxoon CANU and BASSLER, Synopsis American Early Tertiary Cheilostome 

 Bryozoa, Bulletin 96. United States National Museum, p. 56. 



"The ovicell has a 'trifoliate stigma.' There is generally a minute avicularium 

 on the lip to one side. The opercula generally are fairly similar with a nearly 

 straight proximal edge, and in shape rather wider than long, with the muscular 

 attachments rather high up and near the border. Apparently all have the labial 



J -85 



Hlppolozoon hippocrepls ffatepa 



FIG. 142. Genus HippeUoxoon Canu and Bassler, 1917. 



A-G. HippeUoxoon novaeselandi-a-e Waters, 1894. A. Zooecia without ovicellfi, X 35. 

 B. Aperture after the opercuHim has been removed. X 200. C. Zooecia with ovicell, X 85. 

 D. Operculum, X 250. E. Aviculariau mandible, X 250. F. Young zooecium, X 85. G. Dorsal 

 surface, X 5. (A-G after Waters, 1894.) 



H-J. Opercula and mandibles. H. HippeUoxoon lepralioldes Waters, 1894. I H. gelida 

 Waters, 1904. J. H. hippocrcpis Waters, 1904. (H-J after Waters.) 



pore which is often the end of a long tube opening into the zooecium ( = ascopore), 

 proximally to the operculum." (Waters.) 



Genotype. Triphyllosoon (Retepora) moniliferum MacGillivray, 1860. Re- 

 cent. 



Genus RHYNCHOZOON Hincks, 1891. 



1881. Rbynchopora HINCKS, British Marine Polyzoa, p. 3S5. (Preoccupied; replaced by 



Rhynchoxoon in ISlU. 



"This genus seems to be characterized by the possession of a more or less well- 

 developed sinus on the apertura, by its ovicell, which has an entire frontal surface 



