BRYOZOA OF THE PHILIPPINE REGION 429 



Occurrence. — 



D. 5145. Jolo Light, Jolo; 6° 04' 30" N.; 120° 59' 30" E.; 23 



fathoms; co. S., Sh. 

 D. 5147. Sulade Island, Sulu Archipelago; 5° 41' 40" N.j 120° 

 47' 10" E.; 21 fathoms; co. S. Sh. 

 Holotype— Cat. No. 8248, U.S.N.M. 



Genus OSTHIMOSIA Jullien, 1888 



OSTHIMOSIA SIMONENSIS Busk 1884 



Plate 62, figs. 7-10 



1884. Cellepora simonensis Busk, Polyzoa collected by Challenger, Scientific 

 Results Voyage Challenger, vol. 10, p. 200, pi. 29, fig. 9; pi. 76, fig. 8 

 (operculum). 



Measurements. — 



. , [Aa = 0.20mm. ~ ■ jlz = 0.90mm. 



Apertura 7 n <rt Zooecia< 7 n i 



1 lZa = 0.12 mm. U2 = 0.44mm. 



Structure. — The zoarium forms small irregular masses free or 

 attached to nullipores, orbitoides or fragments of shells. The 



Fig. 168. — Osthimosi a simonensis Busk, 1884. 

 Three aspects of the operculum, X85 



zooecia are erect or buried, very convex; the frontal bears large 

 scattered granules; it is surrounded by widely-spaced areolar pores 

 more or less separated by short and little salient costules; it bears 

 in the vicinity of the aperture a salient avicularium with pivot. 

 The aperture is pyriform with two salient condyles placed at the 

 inferior third. The ovicell is globular, salient, smooth, opened by 

 a wide slit which the operculum is never able to close. The oper- 

 culum is variable in size; its proximal border is triangular; two 

 lucidae are arranged laterally at the level of the condyles; there are 

 two strong muscular attachments at some distance from the border. 

 Biology. — Our specimens were living and were in reproduction in 

 February and March, 1908. If we are not mistaken in our determina- 

 tion, the geographic distribution of this species is great, because 

 Busk has noted it at Simon's Bay at the Cape of Good Hope. It 

 belongs to a small group of Cellepores which passes the tropics and 

 accommodates itself to waters which are colder or have a more 

 varied food supply. 



