Plate 31 



Figs. 1,2. Posterula tarsi Smitt, 18(57 (p. 288). 



1. Surface of a bilamellar zoarium, X20. 



2. Interior of zooecia, X20. 



D. 4807. Cape Tsiuka, Sea of Japan. 

 3-10. Cigclisula occlusa Busk, 1884 (p. 291). 



3. Fragment of the bilamellar zoarium, natural size. 



4. Zooecia, X20, bearing spathulated interzooecial avicularia. 



5. A group of abnormal zooecia, X20, and a large spathulate avi- 



cularium. 



D. 5137. Jolo Light, Jolo. 

 ti. Surface, X20, with ovicelled zooecium. The frontal of the ovicell 

 is broken. Some erect opercula are visible in the apertures. 

 D. 5150. Sirun Island. 

 7. Surface, X20, with a complete ovicell bearing its frontal grating. 

 s. Interior of zooecia, X10, showing two condyles on which the oper- 

 culum articulates. Some apertures still have their operculum. 

 D. 5478. Tacbuc Point. 

 9. Surface, X20, with ectocyst preserved and some of the opercula in 

 place. There is a large interzooecial avicularium. 

 10. Zoarium, X20, in which the frontal is very thick and the zooecia are 

 indistinct. The peristomial avicularium opens into llie peris- 

 tomie. 



D. 5137. Jolo Light, Jolo. 



(598) 



