POSTäCtllPT I. SCHRAMMEn'ö HEX ACTINELLID SYSTEM. Il7 



systematic character can only be utilized to characterize a group 

 standing subsidiary to another and more comprehensive grouj) in 

 which the supporting skeletal framework consists of hexactins, — 

 of dictyonally fused hexactins, I may add. Thus, the Hexactinosa 

 and the Lychniscosa, as defined and placed in the system by 

 Schrammen, seem to lose all ground for existence and may be 

 entirely dispensed with. 



On the other hand, if it be justifiable, as I believe it is, to 

 consider Aulocystls as the living representative of all the lychnisco- 

 phorous Hexactinellids that have existed, there can be no tangible 

 reason for not receiving these into (he group Inermia. F. E. 

 Schulze (Chall. Rep.) placed Aulocystis in the same inermate 

 family (Mœandrospongidœ) with Dactylocalyx, Mylmsia etc., and 

 there was a time when it even passed under the name of Myliusia. 

 While I do not follow F. E. Schulze's opinion as to the familv 

 to which Aulocystis should belong, I can not but agree with him 

 in regarding it as one of the Inermia. Granted this point, the 

 three subtribes Schrammen 's may be called the tribes — exactly 

 the same as those in my system — into which the suborder Hexas- 

 terophora may be directly divided. 



It may here be noted that the division I have adopted of 

 the Hexactinellida into the suborders, tribes and subtribes is in 

 complete agreement with F. E. Schulze's idea of the Hexacti- 

 ricUid phylogeny as ably enunciated by him in the end of the 

 Challenger Eeport. If graphically represented, so flir as it goes 

 would take essentially the same appearance as the genealogical 

 tree given by that author /. c. page 495. 



Tokyo, April öth, 1903. 



