194 K. MITSUKÜEI : STUDIES ON 



Description : — " Body elongated, about twice and a half as 

 long as the greatest breadth. Month anterior, subventral. Anus 

 posterior, terminal, slightly dorsal. Tentacles of almost equal 

 size ; their terminal part rather large, almost discoidal, destitute 

 of visible processes. Pedicels eleven along the left side of the 

 ventral surface, and tv,'-elve along the right, rather long and large ; 

 the posterior pairs small. Processes of the dorsal surface very 

 slender and flexible, in one individual twenty, in another twenty- 

 three along each of the ambulacra ; the largest process about as 

 long as the greatest breadth of the body ; a rather short genital 

 process placed in the medio-dorsal hue, a little behind the ten- 

 tacles. Integument very thin and rough, with four sorts of 

 numerous calcareous deposits : scattered spicula ; spinose bodies, 

 cruciform or in the form of an X, with the four arms curved ; 

 large wheels frequently with eight spokes ; and small wheels, 

 sometimes with thirteen spokes. Both sorts of wdieels resembling 

 those of Laimogone icyvUlc-thomsoni (i.e., concave, the felly being 

 directed outwards, not on the same plane as the nave ; the 

 wheels have somewhat the form of a crown) ; between the large 

 and small wheels there are many forms, varying much in size 

 and shape. Colour in alcohol, grey violet. Ends of the tentacles 

 light yellowish-brown. Length about 00 mm. Breadth about 35 

 mm." (Theel 1882, p. 78). 



Remarks : — Next to Ilyodœmon ijimal, this is the commonest 

 holothurian in the deeper parts of the Sagami Sea. It seems 

 to occur in all parts of that sea in depths greater than 250 

 fathoms. 



The measurements, and the number of pedicels and processes 

 in some of my specimens, are as in the following table : 



