500 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Genotype. — IiippadeneXla ( Flustra ) margaritifera Quoy and Gay mar d, 1833. 
Recent. 
It seems to us that it would be better to classify this genus in the Hippoporae, 
although all other authors are agreed in considering the genotype as belonging to 
the genus Porella; we can not maintain it there, the frontal being a pleurocyst and 
the apertura bearing cardelles. 
Family RETEPORIDAE Smitt, 1867. 
Anatomical bibliography. — 1878. Hincks, Notes on the Genus Retepora, Annals and Magazine 
Natural History, ser. 5, vol. 1, pi. 19. — 1S89. Waters, Supplementary Report on the Polyzoa 
collected by H. M. S. Challenger, pi. 3, figs. 5 to 13, 39, 10. — 1S92. Waters, Observations on the 
Gland-lihe Bodies in the Bryozoa, Linnean Society Journal, Zoology, vol. 24, pi. 19, fig. 14. — 
1894. Waters, On Mediterranean and New Zealand Reteporidae and a fenestrate Bryozoan, 
Linnean Society Journal, Zoology, vol. 25, pi. 7. — 1903. Jullien, Bryozoaires provenant des 
Campagnes de VHirondelle, pp. 36, 62. — 1901. Waters, Expedition antarctique beige, p. 77, pi. 
6. — 1909. Levinsen, Morphological and systematic studies on the Cheilostomatous Bryozoa, 
p. 290. pi. 10, pi. 23, figs. 1, 2, 3. — 1909. Waters. Reports on the Marine Biology of the 
Sudanese Red Sea. The Bryozoa, Linnean Society Journal, Zoology, vol. 31, p. 175, pi. 18. — ■ 
1913. Waters, Bryozoa from Zanzibar, Proceedings Zoological Society, London, pi. 72, figs. 1 to 
11, p. 52 (classification). 
The ovicell is hyperstomial, much immersed in the distal zooecium ; it is largely 
open into the peristomie. The zoarimn is generally reticulate; the dorsal face pre- 
sents some projections or vibices without connection with the zooecia and contains 
interiorly some kenozooecia (lacunae of Waters) more or less numerous and 
elongated. The reteporidan pore placed in front of the apertura is according to 
its situation an ascopore or a spiramen; 11 to 16 tentacles. 
Figure 140 sums up our anatomical knowledge of this family. We are 
ignorant of the larva and the generic classification is necessarily impossible to be 
stated with exactitude. 
The classification has been given in 1892 and 1914 by Waters. We have given 
names to the principal groups which he formed. Levinsen introduced into this 
family the genera SeMzotheca Hincks, 1880, and Rhynchozoon Hincks, 1891. It is 
evident that the four genera formed by Waters are in rapport with the hydrostatic 
system. It is now necessary for the zoologist to study the function of calcification 
with all the care possible. 
Genus RETEPORA Imperato, 1599. 
1599. Retepora Imperato, Dell’ historia naturale, libre XXVIII. 
“ This group has a fissure in the ovicell. The proximal edge of the operculum 
is nearly straight, and very similar throughout this group ; labial avicularia occur 
in some but not in all. The oral glands are very well developed.” (Waters.) The 
reteporidan pore is a spiramen. 
Genotype. — Retepora cellulosa Linnaeus-Smitt, 1867. 
Range. — J acksonian-Recent. 
