506 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Occurrence. — 



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



fathoms; S. Sh. (common). 

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



co. S. 

 D. 5144. Jolo Light, Jolo; 6° 05' 50" N.; 121° 02' E.; 19 fathoms; 



co. S. 

 D. 5147. Sulade Island, Sum Archipelago; 5° 41' 40" N.; 



120° 47' 10" E.; 21 fathoms; co. S., Sh. 

 D. 5574. Simaluc Island, north of Tawi Tawi; 5° 30' 45" N.; 



120° 7' 57" E.; 340 fathoms. 

 D. 5577. Mount Dromedario, north of Tawi Tawi; 5° 20' 36" 



N.; 119° 58' 51" E.; 240 fathoms; crs. S.; 12.4° C. 

 D. 5579. Sibutu Island, Darvel Bay, Borneo; 4° 54' 15" N.; 



119° 09' 52" E.; 175 fathoms; fine S., Co.; 13.2° C. 

 Cotypes.— Cat. Nos. 8314, 8315, U.S.N.M. 



FLABELLOPORA ACUTIROSTRIS, new species 



Plate 75, fig. 2 



Description. — The zoarium is free, small (2.5 mm.), suborbicular; 

 the angle of the initial base is large and about the same as the ter- 

 minal angle. The external walls of the zooecia are decorated with 

 pores and irregular granules, an aperture, a transverse avicularium 

 with pivot, with the beak pointed and placed near the distal portion 

 of the aperture and a tubifer avicularium with pivot and with pointed 

 beak turned toward the base. The aperture is rather large, sub- 

 orbicular; the distal sinus is wide and shallow; the peristome is very 

 thin and very little salient; the proximal pore is adjacent to the peri- 

 stome. 



,, . . \ha = 0.12 mm. 



Measurements. — Aperture 7 



r Ua = 0.14 mm. 



Affinities. — This species has a distal avicularium similar to that 

 of Flabellopora elegans and a tubifer avicularium as in F. tubifera; 

 but the zoarium is orbicular and very different from that of these 

 two species. It is moreover very well characterized by the pointed 

 form of the beak of its avicularia. 



Biology. — In the Simaluc locality (550 meters) we have found 

 Flabellopora acutirostris and F. pisiformis which are of very small 

 dimensions and some very small specimens of F. irregularis. The 

 logical deduction of this observation is that the great depth of water 

 is injurious to the development of Flabellopora. 



Occurrence. — D. 5574. Simaluc Island, north of Tawi Tawi; 5° 30' 

 45" N.; 120° 07' 57" E.; 340 fathoms. 



Holotype. —Cat. No. 8316, U.S.N.M. 



