108 AKT. 7. — I. IJIMA : HEXACTINELLIDA, IV. 



iiuous endosomal layer. Parenchymalia, of diactins 

 only. Without pentactinic liypodermalia. Dermalia, 

 various according to species. Gastralia, rough hexact- 

 ius. Oxyhexasters show a greater or less tendency to 

 occur in hemiliexactinose and hexactinose forms. Disco- 

 hexasters in two spherical or approximately spheri- 

 cal forms: macrodiscohexaster and microdiscohexaster. 

 The former with numerous terminals and usually strik- 

 ingly large in size. 



The above diagnosis is drawn up regarding the genus, as it 

 now stands, as made up of the three following species : 



1. A. schidzei I J. 



li. A. ijiviai {¥. E. yicn.) = Calycosaccms ijimai F. E. Sch. 



3. A. mitsukurll Ij. 



The first and the last mentioned species, which were years 

 ago described by me in brief, will be treated of in full in this 

 Contribution. 



The second mentioned species is one which was described by 

 F. E. Schulze ('99), who made of it a special genus, Calyeosac- 

 CU8. He was certainly fully cognizant of the close similarity of his 

 genus and species to my Aulosaccus schulzei, so much so that, as 

 he clearly implies (/. c, p. 100), he would not have hesitated to 

 associate the two forms in the same genus, had it not been for 

 a difference in the character of their dermalia. That difference 

 was the one on which he based the distinction between the fami- 

 lies Asconematidse and Rossellid?e. His species had to be placed 

 under the Asconematidie, while Aulosaccus was to be considered 

 a Rossellid. From such a position, it of course followed that the 

 species must receive a generic designation of its own. Now, in 



