410 NAOKATSU YANAGI AND YAICHIRÖ OKADA: 



attached on stones and shells. Compared with the description and 

 figures given by Robertson of var. catalinensis, the specimens before us 

 differ somewhat in the less number of zoœcia in internodes. On main 

 and secondary branches each internode is made up of three zoœcia, 

 and on tertiary branches it consists of five or seven zoœcia, while in 

 the Catalina form, all the internodes should contain from five to six 

 zoœcia. In main features of the scutum the Hakodate specimens seem 

 to agree entirely with those from Catalina. 



4. Menipea sympodia^ n. sp. 



Pl. VI., fig. I ; textfig. 2. 



Zoarium delicate, forming a tufted growth, 40-60 mm. high, greyish 

 white, attached to substratum by numerous root-fibres. These are 

 given off from either the lateral walls or the dorsal wall of the 

 branches; in both cases extending downwards along the dorsal surface ; 

 they are closely adherent and form a bundle. Branches slender, 

 somewhat depressed, forming pinnate ramifications ; the mode of branch- 

 ing regularly sympodial ; each pinnate ramification consisting,- as it 

 appears, of an axis from which secondary branches arise in alternate 

 disposition, these bearing tertiary branches in a like manner. Joints 

 distinct, yellowish in colour, arising from distinct chambers. Zoœcia 

 elongate, broad, slightly truncated above, attenuated below ; their 

 aperture suboval, occupying usually less than quarter length of zoœci- 

 um, with thin margin, armed with a stout long (about 2 mm.) spine 

 on the upper inner angle and frequently also on the outer. Scutum 

 is unknown, probably absent altogether. Lateral avicularia generally 

 present and occasionally absent, placed at the upper outer angle of 

 zocecium, widened above, with a hooked triangular mandible directed 

 transversely. Frontal avicularia unusually elongate, trumpet-shaped, 

 placed immediately below the aperture, projecting upwards and fore- 

 wards over and reaching beyond the middle of this ; beak pointed. 



