278 ART. 7. — I. IJIMA : HEXACTINELLIDA, IV. 



After attaining a moderately large size, the body is poncli- 

 like, tubular or vase-like, and laterally compressed to a greater 

 or less degree. The wall is moderately thick. The deep gastral 

 cavity extends close to the basal attachment. PI. XXII., figs. 

 1 and 2, and text-figure 11 will serve to give a fair idea of the 

 external appearance of what I consider to be quite or nearly 

 mature specimens. 



FW. 1 shows a specimen — from Inside Okinose by the Ena- 

 line — of a strongly laterally compressed pouch-like shape. Height, 

 97 mm. Breadth sagitally, 40 mm. at the attachment base and 

 77 mm. in the broadest part. Tlie osculum is slit-like and com- 

 paratively small, occupying a position at one end of the upper 

 body-edge, the other end of whicli forms a part of a rounded 

 outbulo-ing of the wall. This outbulging shows a small perforation 

 at the top besides a thinning-out of the wall at two places. It 

 contained in the internal cavity a cluster of Cephalopod eggs in 

 which the embryonal development was still in an early stage and 

 which therefore could not have been there long enough to justify 

 the assumption that their presence had acted as the cause of the 

 outbulging. 



The specimen shown in fig. 2 is from Outside Okinose. It 

 is one of the largest I have seen, measuring 210 mm. in height. 

 The lower half of the body is distinctly compressed laterally, the 

 breadth measuring 90 mm. sagittally and 50 mm. transversely. 

 The upper parts are swollen, the osculum being roundish with a 

 diameter of about 45 mm. Thickness of the wall in the middle 

 of the body, about 14 mm. (exclusive of the gossamer-like layer 

 of prostals). The basal attachment is at one corner of the lower 

 end. In the angular corner opposite to this opens a small secondary 

 osculum of an irregularly oblong shape. On one side of the speci- 



