208 AET. T.— I. IJIMA : HEXACTINELLIDA, IV. 



two exquisite specimens in the possession of the Sei. Coll. Museum. 



The individual of fig. 1 (Mus. No. 244) represents a thick- 

 walled vase, slightly laterally compressed, rounded above and 

 narrowed towards the base by which it is attached to the side 

 of a dead Periphragella elisœ. Entire height, 109 mm.; breadth 

 in the broadest part, 47 mm. by 64 mm.; thickness of wall in 

 the same part, 14 mm. Somewhat on one side of the upper end 

 is situated the roundish osculum, 27 mm. in diameter. A sparse 

 number of inconspicuous prostal diactins, protruding to a length 

 of 14 mm, or less, is present, especially in the region adjoining 

 the oscular margin. 



That of fig. 2 is pouch-like and distinctly laterally compressed. 

 Height, 130 mm. Breadth near the middle, 80 mm. in one direc- 

 tion and 54 mm. in another. Thickness of wall at about the 

 middle, 14 mm. The osculum is of an oblong shape, being elongate 

 in the sagittal line. The basal attachment is on one side of the 

 inferior end. The sponge is therefore bent in the basal region, 

 the bending being as usual in the sagittal plane of the laterally 

 compressed body. Nearly opposite to the basal attachment there 

 exist two small secondary oscula, situated close to each other. No 

 prostalia of whatever sort are to be seen on the specimen. 



Small, and therefore evidently young, specimens of the species 

 are characterized by the possession of fine, but conspicuous, prostal 

 needles. 



The smallest specimen I have had was of a nearly globular 

 shape, measuring oiîly G mm. in lieight and with a roundish 

 osculum of 2 mm. in dia. It showed a small numlier of fine 

 ])rostal needles, apparently in th(' first stage of protruding out- 

 wards. 



Much laro-er are the two vouns individuals shown in PI. XV., 



