BRYOZOA OF THE PHILIPPINE REGION 



65 



rounded termcn likewise ornamented; the opesium has the same form 

 as the zooecium and it is very finely denticulated. Distally, in the 

 walls there is an arch limiting a transverse slit or two lateral cavities 

 corresponding to the septulae. No dietellae. In the superior part of 

 certain zooecia there is a large deep cavity (ovicell?) closed by a 

 special chitinous membrane. 

 Measurements? — 



Opesium!? = - 70 -°- 75 mm - Zocociumf^ - 85 - 1 - 10 mm ' 



\lo = 0.50-0.60 mm. Us = 0.00-0 70 mm. 



Affinities. — This species differs from Membranipora perversa Waters 

 which has an identical superior cav- 

 ity, in the presence of the distal arch 

 and the absence of cryptocyst. It 

 differs from Membranipora profunda 

 MacGillivray, 1895, provided with 

 the same superior cavity in its 

 greater dimensions and in the pres- 

 ence of the distal arch. 



MacGillivray thought that the 

 superior cavity was the trace of an 

 avicularium but this is not possible. 

 Our specimen shows the closing 

 membrane well and it is not a 

 mandible. This structure is per- 

 haps a kind of endotoichal ovicell 

 close to that of the Cellariidae or of 

 the Setosellidae. 



These three species appear to 

 belong to a new genus characterized 

 by the special ovicell. Unfortu- 

 nately the single figured specimen 

 has been found and it is too incom- 

 plete. The physiologic function of 

 the distal arch is unknown. Per- 

 haps it served for the attachment 

 of retractor muscles of the opercu- 

 lum, as in Chaperia. In 1920 we 

 figured as Ellisina profunda Mac- 

 Gillivray a species from the Jack- 

 sonian of South Carolina which is also provided with an identical 

 arch. In its constancy the superior cavity has appeared to us to be 

 a true avicularium. The distal arch is therefore not a generic 

 character. 



Fig. 9. — Genus Cellarinidra 

 Canu and Bassler, 1927 



A-C. Cellarinidra clavata D'Orbigny, 

 1851. A, B. Segment, natural size and 

 much enlarged. C. Transverse sec- 

 tion. 



D-F. Cellarinidra (uronensis D'Or- 

 bigny, 1851. D, E. Segment, na- 

 tural size and enlarged. F. Distal 

 extremity of a segment. 



» In tho citation of measurements ho is the length and lo the width of the opesia Lz and h, similarly the 

 length and width of the zooecia, Lv and is the same for tho vibraculum, Lon and Ion for the onychocellaria, 

 ha and la for the apertura, etc. 



