BRYOZOA OF THE PHILIPPINE REGION 499 



observed in all localities without distinction but they are domiciled 

 on the contrary in places favorable to their life and activities. 



Another movement is suggested to us by the symmetry of the 

 colony and by the thinness of the edges, namely rotation around the 

 axis. This rotation is partial; the animal presents its border (the 

 cross section) to the current and can then oppose a certain resistance 

 to it. Although very feeble, this resistance is sufficient to bring 

 automatically diatoms to the entrance to the tentacles. This rota- 

 tion varies then according to local conditions and can be only of 

 slight amount. The vertical movement is the principal one; it 

 permits the zoarium to reach its prey more easily and to escape 

 famine. It is in order to accomplish this simple movement that the 

 Flabelloporas construct their marvellous architectural system. They 

 mount and descend without cessation. 



They are ravishing small dancers which enliven the somber oceanic 

 passages. 



The previously described species of this genus are as follows: 



Flabellopora (Bipora) umbonata Haswell Australia. 



Flabellopora (Bipora) flabellaris Levinsen, 1909 Australia. 



Flabellopora elegans D'Orbigny, 1882 Malacca. 



Flabellopora (Bipora) mamillosa Maplestone, 1909 Australia. 



FLABELLOPORA ELEGANS D'Orbigny, 1852 



Plate 71, figs. 1-6 



1852. Flabellopora elegans D'Orbigny, Paleontologie francaise, Terrains cre- 



taces, pp. 53, 482, pi. 661, figs. 1-5. 

 1905. Flabellopora elegans Waters, Notes on some recent Bryozoa in D'Orbigny's 



collection, Annals Magazine Natural History, ser. 7, vol. 15, p. 3, 



pi. 1, fig. 5. 



Description. — The zoarium is free, elongated (2.5 mm. to 5 mm.); 

 the basal angle is larger than the terminal angle; the general form 

 is amygdaloid. The walls 16 of the axial zooecia are decorated with 

 a lozenge-shaped or flabelliform area with salient walls. Each area 

 contains the aperture, a distal elliptical, transverse avicularium with 

 pivot and a small proximal poriform avicularium. The zooecia of 

 the initial base and the lateral zooecia are deprived of this area. 

 The aperture is somewhat oval; the distal sinus is wide and semi- 

 circular; the peristome is very thin and little salient; the proximal 

 pore is surrounded by a small peristome adjacent to that of the 

 aperture. 



Measurements. — Aperture], 



r lZa = 0.08mm. 



History. — The colony figured by D'Orbigny is a short and some- 

 what fantastic zoarium. We have had the fortune to discover a 

 very similar one, but this short form passes imperceptibly into the 



>• We can not employ the usual word "frontal" in spite of appearances. 



