62 



HfrôShi oiiniiima : 



have tentacles of the .first order only; '" thè first and Second tentacular 

 canals on each radial canal branching out exactly opposite to each 

 other. 



Here I may add a remark with icgard to PseudöcitcUmis 

 intercédons LampERT, the only species with thirty tentacles among 

 the Dcndrochirotes. According to LUDWIG [23, P- 26], twenty of the 

 tentacles are larger than the remaining ten, which form an inner 

 circle and stand in pairs, the pairs recurring regularly at intervals 

 of every four large tentacles. I am strongly inclined to think that 

 the above enunciation is applicable to this case also. I assume that 

 here each radial canal gives rise to six tentacular canals, 2. c, one 

 in addition to the five tentacular canals to each radial canal of 

 twenty-five-tentacled forms such as Ps. japonicus (tcxtfig. 2). That 

 additional tentacular canal is probably the distalmost or the sixth 

 branch arising from radial canal next after, and on the opposite of, 

 the fifth. Should this be the case, it might be expected that there 

 exists, in each radial calcareous segment [23, Taf. I., Fig. 2], a 

 small notch on each of the two processes forming between themselves 

 the deep median indentation. 



4. Order of appearance of tentacles in ontogeny. 



LUDWIG [30] appears to be the only author who has given any 

 attention to the development of tentacles in polychirotous Cucnmarids. 

 For Phyllophorus urna Grube, he briefly stated that, so far as the 

 first seven tentacles are concerned, the order of their appearance is 

 similar to that he had observed in Cucumaria planci [27, PP- 

 183 — 184].* In the latter species he discovered that ,, die beiden 

 Fühler der beiden ventralen Interradien ihre Wasserkanäle vom 

 mittleren ventralen Radialkanal erhalten, während der Fühler des 

 mittleren dorsalen, sowie derjenige des linken dorsalen Interradius 



* See also diagrams given by Bkcher 2, Taf. XXXVI., Fig. 43 or 3, p. 407, Fig. 1, a. 



