7 2 



IIIROSfII OIISHIMA : 



Integument. — Finely wrinkled all over, except on introvert which 

 is quite smooth ; thick and muscular in contracted specimens, but 

 very thin and leathery in extended ones. 



Tentacles. — Twenty-five in number, present in three different 

 sizes (textfig. 2). As measured in a small but fully extended 

 specimen, the largest ten tentacles situated pairwisc in each inter- 

 radius attain a length of 5 mm. The five medium-sized tentacles, 

 radial in position, are 3 mm. long. The smallest ten tentacles, 

 occurring in a pair in each radius, are only 1 mm. long ; they form 

 an inner circle to that of the others. 



Textfig. 3. 



Amphicyclus japonicus Bell, a Three consecutive segments of calcareous 

 ring viewed from axial side, b-e Tables from introvert seen from above ; / 

 same seen from side, g-i Imperfect tables from general perisome. j Support- 

 ing rod of tentacle, k-l branched rods from tip of tentacle, m End-plate of 

 pedicel ; n curved perforated plates surrounding the end-plate, o anal tooth. 

 ((7x6, b-1 X300, ;;/-fxi50). 



