34<5 



Y. OKADA 



or both ends, show deep-going perforations of a considerable size. On 

 account of the said depressions the plate presents an irregularly canccllatc- 

 like appearance. A structure comparable to the above dorso-basal plate 

 but totally different in structural details, is found in Tulntlipora tumida Smitt 



12. Tubttlipora eboracensis (Busk) 1S86. 



Idmonea eboracensis, Busk 1886 (5), 12, pi. iii, fig. 4. 

 Alecto polystiçha, Ortmann 1890 (1), 62, pi. iv, fig. 35. 

 Idmonea concinna, Marieston 1908 (2), 234, pl. vii, fig. 5. 



Specimens from : Yodomi Bank, 8C-100 fms.; Okinosé 312 fms., small 

 colonies attached on a Hcxactinellid ; Off Jûgashima, 5C-100 fms., small 

 colony attached on Crisulipora Tjimai. The specimens vary considerably 

 in the size and arrangement of zooecia and in some other characters, but all 

 agree in the characters of ooecium. 



13. Tubulipc.ra tnisahiensis n. sp. 



Zoarium adherent by thin lamina which does not extend beyond its 

 margin ; small specimens nearly flabclliform ; larger specimens irregularly 

 circular with two or three indentations at margin. Zooecia long, slender, 

 erect or sub-erect, radiating from the centre ; partly arranged in radial rows 

 of 3—7 zooecia each and partly joined together into bundles of 2 or 3 zooecia ; 

 the basal third of their length immersed, the remaining two-thirds being 

 free and either simply bent upwards or recurved. Zooecial aperture cir- 

 cular, 0.10 mm. in diameter, frequently elliptical. Dorsal surface smooth ; 

 margin of primitive disc without teeth. Ovicell an extensive inflation of 

 zoarial surface underlying several zooecial tubes, with minutely punctured 

 surface and irregularly lobate outline. Ooeciostome simple, at first verti- 

 cally standing but soon bending in transverse direction, frequently entirely 

 straight, arising close to zooecial bundles on the proximal side or bet- 

 ween rows of zooecia. Ooeciopore nearly circular, 0.04 mm. in diameter, 

 rarely elliptical. 



