102 



s. GOTO 



It thus appears that both the radial ratio and the number of 

 marginal plates are subject to a good deal of variation, the latter 

 evidently depending primarily on the size of the specimens. It may 

 also be mentioned that many of the long armed specimens of the 

 Albatross collection (1906) can not be distinguished specifically from 

 the Ct. procurator of Sladen, as figured in the Challenger Report. 



The abactinal surface is either plane or convex, depending 

 upon the amount of mud contained in the stomach when the 

 specimen was put in preservative fluid, and the central conical 

 protuberance is very conspicuous. In some specimens, especially 

 of larger size, five radial lines can be seen extending from the 

 central process to the apices of the arms. The actinal surface is 

 nearly plane and covered over with ä humid membrane, which 

 masks the individual plates of tliis side, so that they can usually 

 be distinguished only after treatment with caustic potash. The 



