ART. 14 FOSSIL AND RECENT BRYOZOA CANU AND BASSLER 91 



according to circumstances. We have always thought that this is 

 an important function which is of generic importance. We violate 

 this principle sometimes, but it is only in genera in which the species 

 are rare and in order not to change the nomenclature uselessly. 

 This is not the case in the genus Stylopoma, in which we already 

 know the following seven species. 



Stylopoma spongites Pallas, 1766, Miocene — Recent. 



Stylopoma minuta Canu and Bassler, 1923, Miocene (Jamaica). 



Stylopoma magniporosa Canu and Bassler, 1923, Miocene (Santo 

 Domingo). 



Stylopoma projecta Canu and Bassler, 1923, Pleistocene (Panama). 



Stylopoma distorta, new species, Recent (Philippines) . 



Stylopoma parviporosa, new species. Recent (Philippines) . 



Stylopoma grandis, new species, Recent (Philippines) . 



This is an equatorial genus but it has been observed in the larger 

 ■oceans such as the Atlantic, Indian, and Pacific. We have not yet 

 found it in the Southern Hemisphere. 



STYLOPOMA SPONGITES Pallas, 1766 



Plate 10, Figures 8-10; Plate 32, Figure 9, text Figure 14 



1918. Schizoporella spongites Waters, Bryozoa of the Cape Verde Islands. 

 Journal Linnean Society, Zoology, vol. 34, p. 16, pi. 2, figs. 10-13. 



1923. Stylopoma spongites Canu and Bassler, North American Later, 

 Tertiary and Quaternary Bryozoa. BuU. 125, U. S. National Museum, 

 p. 102, pi. 17, figs. 1-12. (Bibliography, geographic distribution.) 



Tir ^ A . fy^a = 0.10 mm. (without sinus). 



Measurements. — Aperture<^7 ^ ^r. r^ -, ^ 



^ [to = 0.12-0.15 mm. 



r^ . iLz = 0.50 mm. 



Us = 0.35 mm. (variable). 



Variations. — Smitt in 1873, Waters in 1918, and ourselves in 1923 

 have indicated the great zooecial variations of this species. The 

 colonial variations are also numerous; the zoaria can be observed in 

 spongy masses, often very large, in multilamellar hemescharian colo- 

 nies, in uni or multilamellar encrusting surfaces, and in unilamellar 

 cylindrical forms. Furthermore, in the waters off Florida we have 

 observed magnificent bilamellar dendroid colonies of free or anasto- 

 mosing, very regular, compressed fronds. This is a very capricious 

 animal which can adapt itself to all the biologic conditions possible; 

 but this faculty of adaptation is always accompanied by correlative 

 variations. 



Structure. — On the interior the tremopores are very small and at a 

 magnification of 20 diameters they are visible only by transparency. 

 There are no condyles to the aperture. The operculum is very thin 

 and quite fragile; the proximal rimule is subtriangular and it is much 



