BRYOZOA OF THE PHILIPPINE REGION 555 



The ovicell is of the Ascosoecia type; it is a long elliptical sac, smooth, 

 globular, a little broader than the branch, perforated by tubes gen- 

 erally closed. The oeciostome is terminal, small and semicircular. 

 We have discovered only 7 ovicells and have figured the two best but 

 they are not perfect. On the ovicells of fossil Ascosoeciidae we have 

 never seen the oeciostome, so that the present discovery is important 

 as it permits a better understanding of the biology of the specimens of 

 this interesting family which appears to be special to warm zones. 



The discovery in the equatorial zone of a large number of Cre- 

 taceous genera permits us to verify that the general morphology of the 

 bryozoa was already well fixed in the Mesozoic era and that it is useless 

 to resort to the transcendant hypothesis in order to restore and under- 

 stand the structure of specimens found in the Upper Cretaceous. 



The alternate lines are uniquely formed of two tubes one of which 

 has a salient peristome and the other, the more exterior, is deprived 

 of it. Our photographs in this feature absolutely conform to Smitt's 

 illustration. 



The dorsal is almost flat; the sulci are very shallow and the vacuoles 

 are long, quite visible, narrowed above. 



The specimens are very small and fragile and difficult to section. 

 We have succeeded in preparing some sections which conform com- 

 pletely to the structure which we have given for the fossil species. 19 

 The tubes are cylindrical, slightly club-shaped, with triparietal gem- 

 mation. The vacuolar canals are long, recurved only at their extrem- 

 ity; they are so fine that they are difficult to see in the thick epitheca 

 and opaque from the dorsal. 



The transverse section is triangular, surrounded by a very thick 

 epitheca. The tubes are polygonal and nearly of the same size. 



Biology. — This species does not extend into the interior of the 

 Philippine Archipelago but it is restricted to the Pacific or its 

 immediate vicinity and in localities where a marine current exists. 

 However its geographic distribution is very great because we have 

 found it in the Atlantic and in the Gulf of Mexico. It lives between 

 the ninth and thirtieth parallels, not extending to the Equator and 

 has not yet been observed in the Southern Hemisphere. 



Our remarks on Ilornera pinnata apply also to Crisina canariensis. 

 We can hardly understand how a well developed dendroid ensemble 

 can keep in equilibrium on a small fragment especially in moving 

 waters. The physiologic role of the vacuoles must be essential to 

 the establishment of this equilibrium, but how? On the other hand, 

 it is more reasonable to think that the small capillary tubes are more 

 in rapport with the formation of the zoarial epitheca. 



Regarding the much calcified species there is another mystery, 

 namely that of oxygenation. How does this indispensable function 



'• 1922. Canu and Bassler, Studies on Cyclostomatous Bryozoa, Proc. U. S. National Museum, vol. 81» 

 p. 117, pi. 20, figs. 9-21. 



