200 ART. 7. 1. IJIiMA : HEXACTINELLTDA, IV. 



Soft Parts. 



Care was taken by Kuma, the collector, to preserve in strong 

 spirit small pieces from both the specimens described above ; so 

 that I have been able to make some studies on their soft parts. 

 This however has yielded no special additions to the knowledge 

 we already possessed. I therefore restrict myself to recording 

 only a few points. 



The thiml)le-like and sometimes cup-like chambers were 

 observable with especial distinctness in the specimen (No. 403) 

 refei-rcd tentatively to S. eniacanthns. Here they have a dinmeter 

 of 110-187/^ (on an average, 155//). The usual reticular structure 

 of the chamber-wall is in places very beautifully shown (PI. XIV., 

 figs. 20 and 21). The meshes, the open nature of which can not 

 be doubted, measure about 5/^- in length of sides. Observed under 

 the immersion system, every nodal point is seen to be occupied 

 by a vesicular, not specially well-stained nucleus, 1.7-3.4/^ in 

 diameter and containing some chromatic granules. The smaller 

 nuclei present a more compact appearance than those of a larger 

 size. In optic sections of the wall, the nuclei have a distinctly 

 oval outline. 



In both specimens the trabecuhe are frequently spread out 

 in the form of a membrane especially on the surfaces which come 

 in contact with the external world, — not only on the dermal and 

 irastral sides but also alon«; the lumen of the larwr canals. The 



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finely granular substance of trabecuhe may exhibit in the film-like 

 parts somewhat deepei'-stained and often irregularly liranched 

 streaks, which in some places may run more or less parallel to 

 the edge of the film-like plate (PI. XIV., figs. 18 and 19). The 

 first thouo-ht on observinir them would likelv be that we have 



