ON SOME JAPANESE CALCAREOUS SPONGES. 



31 



Textfig. 6. Heteropia striata. 



a, b, Dermal triradiates. 



c, d. Subdermal triradiates. 



e, f, Subgastral triri^diates. 



g, h, Gastral triradiates. 



i, j, Gastral qnadriradiates. 



k, 1, m. Dermal oxea. 



(a— j, 150 X ; k— m, 40 x ). 



straight excepting the sHght curvature near base, gradually taper- 

 ing to a sharp point. The shorter ray almost straight, tapering 

 from base to sharp point. In a typical case, the basal ray is 

 190 /^ long ; the longer paired ray 130 ;" long ; and the shorter 

 paired ray 110/^ long; all 16 fi thick. 



Subgastral triradiates (textfig. 6, e,/). — Sagittal, with sharply 

 pointed rays of nearly equal thickness. Basal ray straight, taper- 

 ing from base to sharp point, 150-300^ long and 16-20/^ thick. 



