ox SOME JAPAMESE CALCAREOUS SPONGES. 13 



Siibgastral triradiatcs (toxtfig. 2, //, /). — Strongly sagittal, 

 nearly similar to tiil)ar triradiates but with oral angles widcT in 

 varying degrees. Basal ray straight, smooth, gradually sharp- 

 pointed, 420-480/^- long and 20-24/^ tliiclv. Paired rays lying not 

 in the same plane with basal i*a}', equally long, slightly curved, 

 gradually sharp-pointed, 180-250,« long and lG-24/>'- thick. 



Gastral triradiates (textfig. 2,/, /.). — Slightly sagittal. All 

 rays equally thick. Basal ray quite straiglit, smooth, tapering 

 from base to the sharp point, 180-270/^ long and l()-20 ,« thick. 

 Paired rays equal in length, almost straight excepting a slight 

 curvature near base, gradually sharp-pointed, 170-210 « long and 

 10 ,« thick. 



Gastral quadrir a diätes (textfig. 2, /, m). — Facial rays exactly 

 similar to gastral triradiates. Basal ray 170-280//- long and 11]- 

 20," thick. Paired rays 200-210// long and 10-20// thick. Api- 

 cal ray curved, sharp-pointed, nearly as thick as the facial rays 

 but much shorter, 50-70// long 10// thick. 



Triradiates of oscukir margin (textfig. 2, n). — Basal ray quite 

 straight, sharply pointed, 140-280 /^ long and 8-12 // thick. 

 Paired rays slightly curved, standing nearly at right angles to 

 basal ray, thicker and shorter than the latter, 100-170 // long and 

 12-lQ/Jt thick. 



Quadriradiates of oscular margin (textfig. 2, o, ^j). — Facial 

 rays exactly similar to triradiates of the oscular margin. Apical 

 ray very short, slightly curved. Basal ray 200-350 /^ long and 

 12// thick. Paired rays 150-220// long and 12-10// thick. 



Large oxea (textfig. 2, q, r, s). — More or less curved, of vary- 

 ing lengths, nearly uniformly thick in the greater part of their 

 length but tapering at both ends which are sharply pointed, 0.0- 

 1.8 mm. long and 30-50 // thick. 



