500 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



elongated amygdaloid al form which is the more frequent; the details 

 of the surface are moreover identical on all the colonies. 



The drawings of Waters, 1905, are perfectly exact and give the 

 true form of the lozenge-shaped area, poorly figured by D'Orbigny. 

 However the proximal sinus figured is only an alteration very 

 common in all the genus and arising from the union of the aperture 

 and of the proximal pore; in reality the real sinus in close connection 

 with the compensatrix is indeed proximal. 



Variations. — We have figured the basal angle with small pores, a 

 terminal angle with incomplete zooecia and a superior lateral cross 

 section showing also some zooecia in process of formation. On the 

 longitudinal section the zooecia are hexagonal, elongated with one 

 of the exterior sides occupied by the aperture. The interior con- 



Fig. 209. — Apeitures of Flabellopora 



A. F. elegans, new species. B. F. tuberosa, new species. C. F. irregularis, 

 new species. D., E. F. tubifer, new species. F. F. transversa, new species. 



firms the eccentric position of the aperture and there is no connec- 

 tion with the exterior area. 



Biology. — All our specimens were dead. They probably did not 

 live at the depth at which they were dredged, although they are small 

 free colonies submerged in the sea like submarines. We are ignorant 

 of the habits of the larva and we do not know if it lived in the vicinity 

 of the sea bottom. 

 Occurrence. — 



D. 5134. Balukbaluk Island, Sulu Archipelago; 6° 44' 45" N.; 



121° 48' E.; 25 fathoms; fine S. 

 D. 5137. Jolo Light, Jolo; 6° 04' 25" N.; 120° 58' 30" E.; 20 



fathoms; S. Sh. 

 D. 5141. Jolo Light, Jolo; 6° 09' N.; 120° 58' E.; 29 fathoms 



co. S. (common). 

 D. 5144. Jolo Light, Jolo; 6° 05' 50" N.; 121° 02' 15" E. 



19 fathoms; co. S. 

 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.; 120° 



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

 D. 5151. Sirun Island, Sulu Archipelago; 5° 24' 40" N.; 120° 

 27' 15" E.; 24 fathoms; co. S., Sh. 



