BRYOZOA OF THE PHILIPPINE REGION 505 



FLABELLOPORA TUBIFERA. new species 



Plate 73, figs. 6-7 



Description. — The zoarium is free, amygdaloidal, wide from 6 to 

 7 mm. in length, of semitransparent calcite. The angle of the initial 

 base is larger than the terminal angle. The external wall of the 

 zooecia is decorated with tuberosities, poriform avicularia and the 

 larger elliptical avicularia with pivot; the avicularian chamber is a 

 veritable tube salient but very oblique. The aperture is small, 

 somewhat elongated; the peristome is little visible; the distal sinus 

 is minute; the proximal pore is placed on the peristome and is 

 scarcely discernible. 



Measurements. — 

 Superficial \ha = 0.10 mm. Deep fk = 0.10mm. 



aperture [la =0.10 mm. aperture Ua =0.08 mm. 



Structure. — The zoarium is semitransparent and gives to this 

 beautiful species a strange and very special aspect. By an optical 

 effect the apertures seem small; but under the microscope their 

 dimensions are close to those of all the other Flabellopora. When 

 the colony is calcified the aspect is somewhat different but the presence 

 of granules still permits the identification. 



The richness of ornamentation is peculiar to each colony, for it is 

 difficult to find two colonies identical in aspect. Moreover when the 

 zoarium is dead and when it is little worn the surface is easily altered. 



The view of the interior shows the usual arrangement of the 

 difference of orientation of the zooecia of the initial base. The 

 longitudinal and transversal sections show the avicularian chambers 

 excavated in the great thickness of the distal wall of the zooecia. 



The tangential section reveals the arrangement of the avicularia; 

 although they appear at the surface as irregularly scattered, they are 

 in reality arranged only in the usual manner, that is in double rows 

 and avicularia alternating between the oblique rows of apertures. 



The superficial apertures on the calcified specimens appear some- 

 what larger than the apertures arranged at the bottom of an elliptical 

 peristomie. The apertural measurements vary in different specimens. 



Affinities. — This species is perhaps identical with Flabellopora 

 mamillata Maplestone, 1909, from Australia and differs from it only 

 in its tubifer avicularia. 



Biology. — This species is not rare in the calm waters of the Sulu 

 Archipelago. It appears also in the China Sea and we have found 

 it in the very rare locality of Sibutu. The largest of our specimens 

 were dredged in deep waters. 



The special nature of the zoarium indicates a particular nourish- 

 ment which can not be discovered without the examination of speci- 

 mens preserved in alcohol. 



