BRYOZOA OF THE PHILIPPINE REGION 315 



Affinities. — Our micrometric measurements are the average for the 

 variations are very great. The zooecia are not rigorously oriented 

 but they are never in disorder as in Stylopoma spongites Pallas or in 

 Stylopoma grandis. The lamellae easily become detached when the 

 colony is dead. 



Biology. — Our largest zoarium is from locality D. 51G2 (372 meters) 

 so that great depths are favorable to the species. The species was 

 in reproduction February 18 to 22; the depth therefore does not 

 modify the time of reproduction. 

 Occurrence. — 



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



co. S. 

 D. 5145. Jolo Light, Jolo; 6° 04' 30" N.j 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. 

 D. 5162. Tinagta Island ; 5° 10' N.; 119° 47' 30" E.; 230 fathoms; 

 S. brk., Sh. crs.; 11.6° C. 

 Cotypes — Cat. Nos. 8071, 8072, U.S.N.M. 



STYLOPOMA PARVIPOROSA, new species 



Plate 36, figs. 3-6 



Description. — The zoarium encrusts fragments of shells or of sea 

 urchins. The zooecia are distinct, separated by a furrow, elongated, 

 hexagonal, very regular; the frontal is convex and perforated by a 

 multitude of small tremopores; it bears in the immediate vicinity 

 of the apertura a very small avicularium with a salient beak. The 

 apertura is small, as long as broad; the anter is semielliptical; the pos- 

 ter is rectilinear and notched by a narrow, expanding rimule. The 

 ovicell is large globular, porous; it entirely surrounds the apertura 

 and its avicularium. 



Measurements. — 



Apertura'^ = - 10 mm ' Zooeciajf 2 = °'f "°- * 4 mm ' 



Ua = 0.10mm. Xlz = 0.30-0.40 mm. 



Affinities. — This species is very well characterized by its small 

 tremopores with thick borders very visible at a magnification of 

 85 diameters. The anccstrula is very small and reduced to an ellip- 

 tical aperture. 



At first glancej;his species resembles very much Schizopodrella isa- 

 belleana Smitt, 1873, but differs, however, in its regular zooecia, in 

 its smaller micrometric measurements, in its much more numerous 

 and smaller tremopores and in its shorter oral avicularium arranged 

 almost longitudinally and rarely transversely. 



