68 



TIIROSIII OIISHIMA : 



Disi îrbut ion of pedi- 

 ^••v. eels and 



papillic. 



Arrange- 



ment of tenta- 



cles & their number, 



Pedicels arranged in distinct rows 

 in ambulacra. 



Pedicels distributed 

 in both ambulacra 

 and interambulacra, 

 scarcely or not at 

 all showing zonal 

 arrangement. 



Interambulacra 

 devoid of pedi- 

 cels. 



Interambulacra 

 with a few papil- 

 la; or pedicels. 



In 2 orders. 



'5 



Oratici discre- 

 pant. 



Gratia cucttmi- 

 formis. 



Orcula 



(most species). 



20 



Pseudocttcumis 

 (most species). 



Aclinocucumis. 



Pliylloplipnts. 



In 3 orders. 



2 5 



Pseudocttcumis 

 japoitictts. 







3° 



Pseudocttcumis 

 intercedete. 







It is obvious that the system of the Phyllophorinœ as it now 

 stands is in much confusion. The genus Orcula includes all the 

 fifteen-tentacled forms and even the stichopodous species O. dis- 

 crcpans Sluiter, while Pseudo cucumis includes forms in which the 

 tentacles number i8 — 30, and in which the zonal arrangement of 

 pedicels is much pronounced. 



I agree with ÖSTERGREX [33, p. 103 ; 34, P- 9 ; 35 ; P- 659 and 

 38, p. 23] in uniting Orcula with Phyllophorus. As reasons thereof 

 I may adduce, firstly, the fact that the presence of a fourth tentacle 

 in each radius of any twenty-tentaclcd form is often difficult to make 

 out and is thus liable to be overlooked ; and secondly the fact that 

 tentacles number fifteen or twenty can not be made a definite 

 criterion for separating the two genera, since the third and fourth ten- 

 tacles may easily be taken for a pair belonging to the second order. 

 The same may be said for the genus Pseudo cucumis which should 

 include the stichopodous forms with 15 — 20 tentacles. I see no reason 

 for assuming generic difference between Orcula discrcpans [Sluiter 

 44, p. no] and Pseudccucumis quinquangularis SLUITER [44, P- 108], 

 the former said to have fifteen tentacles and the latter eighteen. 

 Further, the species O. cucumiformis should also be referred to 



