BRYOZOA OF THE PHILIPPINE REGION 



467 



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Fig. 198. — Genus Urceolipora MacGillivray, 1881 



A-J. Urceolipora nana MacGillivray 1881. A. Zooecia with open operculum. 



The figure only shows the strongest of the longitudinal ridges which keep the 

 covering membrane (ectocyst) stretched, X40. B. Two zooecia with ovicell, from 

 the frontal surface; X40. C. A sagittal section through three zooecia with 

 endozooecial ovicell. The covering membrane, the lowermost part of which 

 represents the ectozooecium, is too thick, as it has been drawn with a double 

 outline to make it distinct, X40. D. A zooecium with ovicell, from the basal 

 surface. The uniporous septulae of the basal surface and of the distal wall are 

 seen; X40. E. A transverse section through a branch. Two zooecia and three 

 of the ridges, which keep the covering membrane stretched, are seen; X40. 



F. A transverse section through the proximal part of an ovicell and through a 

 portion of the adjacent zooecium. The endozooecium is seen innermost and on 

 each side of its aperture one of the trapeziform projections which contribute to 

 keep the covering membrane stretched. On each side of the covering membrane 

 internally is seen the collar-shaped ridge which surrounds the proximal part of 

 the ovicell, and lowest down the separating wall towards the adjacent zooecium. 

 Outside the endozooecium the distal wall with its septulae is seen (On account <»f 

 incorrect shading it seems to be arched) X55. (A-F. After Levinsen, 1909.) 



G. Frontal view of a zooecium showing the arrangement of pores; X50. H. 

 Lateral view of a zooecium, X50. I. View of aperture showing the movements 

 of the operculum and the entrance of the compensatrix, X 100. J. A fragment 

 of a colony, X25. (G-J. After Busk, 1884.) 



