234 



K. MITSUKL"!!! : STUDIES ON 



prolongations. Stone-canal one, attached to the dorsal mesentery. 

 Polian vesicle one, vesicular. 



Calcareous deposits : — (i) Large scales or plates 0.0 mm. large, 

 or smaller, easily visible with a hand-lens ; they give firmness 

 to the perisome. Tlie large- sized plates 

 lead down to smaller forms witli fewer 

 openings (textfig. 45b). (ii) Small 

 rosette-like figures, mostly cruciform in 

 shajDe, lying outside of the scales (a), 

 (iii) Supporting rods which, unlilvc those 

 of Thkel' sspecimens, or Sluiter's, are 

 irregular plates with holes in irregular 

 distribution (c). 



Eemarhs : — This is one of the com- 

 monest liolothurians near Misaki. The 

 specimens were found attached in a 

 considerable number to the shells of 

 Ostrea gigas, as well as to sea-weeds, 

 brought up by divers from a depth of 

 3—4 fathoms. 



It is not without some hesitation that I identify these 

 specimens with C. capensis of Thkel. However, in the body form 

 and anatomical relations, as well as in the distribution of pedicels 

 and the character of calcareous deposits, they must be said to agree 

 essentially with Thkel"s description. Only the specimens in question 

 are very much smallei'. Sluiter has found the same to be the case 

 with his specimens. Theel's specimens measured .'j3 mm. and 

 Sluiter's 33 mm., while mine are all less than 20 mm. at the most. 

 One of the largest, wdien living, was 15 mm. x 4 mm. Under the 

 circumstances it has seemed to me best to put this as a variety 



Textfig. 4S. 



Cucumaria capensis, \iir. parva : 

 a — Kose(te-like, cruciform bodies ; 

 h — SniiiU fonii of scale or plate ; 

 r — Siippurtinf; rod. ( x 300). 



