88 



K. MITSUKFEI : STUDIES ON 



Textfig. IS. 



Holnthuria îsuga : 



a — c — Tables of dorsum: 



(7—/ — Same of ventrum. 



(x300). 



Remarhs 



besides these, some very peculiar 

 modifications of tlie table. The 

 edges of the crown, which may or 

 may not be complete, send out- 

 ward processes which unite with 

 similar processes arising from the 

 outer parts of the disk. The re- 

 sult is sometimes a very irregular 

 and complicated figure. Buttons 

 are mostly irregular in shape. 

 I must confess that I have been sorely puzzled 

 over these specimens. It seems probable, judging from w^hat has 

 been l)rought out in Stlchojms japonlcus, that the tables found in 

 these specimens are senile forms. We must then judge by those 

 of the specimens that show the tables in a nearly perfect state. It 

 is evident that my specimens are closely related to liolothuria 

 vagalmnda. But there is this difference : in //. vaçiahunda the 

 more imperfect the tables are, the larger becomes the crown of 

 the spire in comparison with the disk, while in the specimens under 

 treatment the crowns are much smaller than the disk. It seemed 

 to me that my specimens come also very close to //. fusco-ruhra, 

 but in that species the pedicels should be '• much more numerous 

 than the dorsal papihas which are comparatively few, so that an 

 obvious line of demarcation is discernible between the dorsal and 

 the ventral surfaces " (Thkel '80, }). 182), whereas in my speci- 

 mens the pedicels extend all over the liody except on the narrow 

 median dorsal streak wiiicli has long papilla>, and there is no 

 obvious demarcation between the dorsal and the ventral surface. 

 Moreover, for //. fusco-ruhra no mention was made by Thkel of the 

 peculiarly modified tables, although this may be duo to the fact 



