BRYOZOA OF THE PHILIPPINE REGION 



223 



Fig. 83.— Genus Flabellaris Waters, 1898 



A. Flabellaris triseriata Busk, 1852. Diagram showing bifurcation. 



B, C. Flabellaris spicata MacGillivray 1886. B. A system of branches 

 showing a sympodial form of colony associated with the suppression of one of 

 the joints at each bifurcation. C. Lateral view of two zooecia without ovicells; 

 j. av., frontal avicularium; i. av., internal avicularium. 



D. Flabellaris marionensis Busk, 1884. Basal view showing four internal 

 avicularia (i. av.); 1. av., lateral avicularium. (C, D, after Harmer, 1923.) 



E. Flabellaris ornata Busk, 1852. Anatomical structure (after Marcus, 1922). 



single external avicularium. The ends of two interior robust spinous processes 

 are seen in the proximal portion of the frontal area. H. The proximal half of a 

 zooecium from the basal surface after the removal of the latter, X75. An 

 internal avicularium, four spinous processes and the horizontal part of the distal 

 wall with its pore chamber (dietella) are seen. I. The proximal half of another 

 zooecium treated in the same way, X75. The mandible of the avicularium has 

 been removed. J. Some zooecia from the basal surface, X40. The internal 

 spinous processes, the dietella of the distal wall and the heart-shaped septula 

 are seen. K. Same zooecia, lateral view, X55. The bent distal wall, the in- 

 ternal avicularium (a v) and a robust forked process are visible. L. Some 

 marginal zooecia, lateral view, X40. Two radical fibers seen to originate from 

 their chambers. M. Dorsal surface showing the internal denticles, X25. N. 

 Lateral view showing septulae, X25. The lower part of the younger zooecia 

 comes under the aperture of the older ones. (E-M, after Levinsen, 1907.) O. 

 Section, X85, showing the position of the ovarium (o) and the cellular mass 

 (c. m.). P. Cellular masses of the parenchvin threads (mesenchyme) attached 

 to those passing through a septula (r. p.) and also attached to the walls of the 

 stomach, X500. Q. Distal septula, X85. 11. The ovarium, X500, consisting 

 of a large number of ova around the border. (M-R, after Waters, 1S9S.) S. 

 Lateral view of two zooecia, with ovicells (ov.) and frontal avicularia if. av.); 

 I. r. p., lateral rosette-plates; sp., base of spine; i. sp., internal calcareous spines. 

 T. Lateral view of two zooecia without ovicells; /. av., frontal avicularium; 

 i. av., internal avicularium; /. r. p., terminal rosette-plate. U. Frontal view; 

 cr., the part of the cryptocyst which overlies the internal avicularium u'. av.), 

 of which the proximal end (p.) is seen partly through the frontal wall and partly 

 through the lateral wall of the zooecium; t. r. p., terminal rosette-plate. (S-U, 

 after Harmer, 1923.) 



