BRYOZOA OF THE PHILIPPINE REGION 321 



indicates a true Ilippoporina, for the poster is not triangular. The 

 operculum confirms the examination of the aperture. There are 

 two large condyles on the interior. 



Biology. — The marginal zooecia are not ovicelled, the ovicell being 

 placed on the distal zooecium forms later and when by regeneration a 

 female polypide succeeds an ordinary one. 



This species is never abundant, but it has been dredged to the north 

 and south of the Sulu Sea in several localities. The specimens from 

 the deep water near Mount Dromedario are similar to the others and 

 the species does not appear sensible to bathymetric influence. 

 Occurrence. — 



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



20 fathoms; S. Sh. 

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



19 fathoms; co. S. 

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



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

 D. 5179. Romblon Light, Romblon; 12° 38' 15" N.; 122° 12' 



30" E.; 37 fathoms; hard S. 

 D. 5192. Jilantaguan Island, off northern Cebu Island; 11° 09' 



15" N.; 123° 50' E.; 32 fathoms; green S. 

 D. 5478. Tacbuc Point, Leyte; 10° 46' 24" N.j 125° 16' 30" 



E.; 57 fathoms; Sh. 

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

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

 Cotypes — Cat. Nos. 8084, 8085, U.S.N.M. 



HIPPOPORINA PLANULATA, new species 



Plate 37, fig. 6 



Description. — The zoarium encrusts bryozoa. The zooecia are 

 distinct, separated by a furrow, small, hexagonal; the frontal is plain 

 and smooth. The apertura is very small; the anter is pyriform; the 

 poster is somewhat enlarged in its proximal portion. The ovicell is 

 large, placed on the distal zooecium of which it covers a large part, 

 smooth and globular. 



Measurements. — 



Apertuiaj J° = 009 mm ' Zooecia!^ =0.25-0.30 mm. 



Ik -0.07 mm. \lz -0.25-0.30 mm. 



Affinities. — This species differs from Hippoporina porcellana Busk, 

 1860, in its much smaller micrometric measurements and its plain 

 frontal. It is one of the smallest species known. 



Biology. — Our specimens were living and were in reproduction and 

 fixation February 15, 1908. The ectocyst alone is pigmented and of 

 a beautiful, clear light color. 



