194 K. MITSUKUEI : STUDIES ON 



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

 long as the greatest breadth. Mouth antei-ioi-, 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 twelve 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 line, a httle behind the ten- 

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

 numerous calcareous deposits : scattered spieula ; spinoso bodies, 

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

 large wheels frequently with eight spokes ; and small wheels, 

 sometimes with thirteen spokes. Both sorts of wheels resembling 

 those of Ldimogoue u-i/villc-ihomsojii (i.e., concave, the felly being 

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

 A\'heels 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." (Thkel 1882, p. 78). 



Remarks : — Next to Ilyoda'mon ijimai, 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 gi-eater than 250 

 fathoms. 



The measurements, and the number of pedicels and processes 

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



