174 



JSAO IJIMA. 



some other parts of the world. It should be noted that the descriptions in 

 this paper refer in particular to A. beatrix orientali^, unless otherwise re- 

 ferred to in special. The notes were drawn up with the view of creating a 

 basis of comparison to be utilized in my forthcoming' report on the hex- 

 actinellids collected by the " Siboga " in the Malayan seas. It may as well 

 be mentioned here that, of the rich material of A. beatrix orientalis col- 

 lected by me in the Sagami Sea, I have subjected more than a dozen 

 different stocks to specially close studies for the purpose of determining the 

 range of individual variations. Further stood at my disposal some speci- 

 mens of the same form from the Suruga Bay, the Gulf of Kagoshima, the 

 China Sea and the Philippine Islands. 



In general habitus the oriental form exhibits the same extensive range 

 of variation as is ascribed to the entire species. What may be considered 

 as an individual is either an irregular, dichotomously branching, simple tube 

 (" ramosa " type), or consists of an erect axial calyx bearing a number of 

 radial tubo-branches at different heights between the base and the upper 

 end. The tubes, be these parts of individuals of the " ramosa " type or 

 branches of axial calyx, measure generally 4 — S mm. in diameter, seldom 

 reaching up to 10 mm. The calyx may reach So mm. or thereabout in 

 height, more or less widening superiorly up to 25 mm. or more across. The 

 wall, irrespective of the configuration of the parts it belongs to, is generally 

 from 0.6 mm. to nearly 1 mm., seldom up to 1.4 mm., thick. The honey- 

 comb-like radial canals of the wall skeleton measure 0.6 — 0.8 mm. in dia- 

 meter. It is unnecessary to go into further details of the macroscopic 

 structure, as this agrees in all essential points with what is already known 

 of it. Only it should be pointed out that, as regards the dimensions of 

 parts, the oriental specimens fall considerably short of the rnaxinum at- 

 tained by some of the Indomalayan specimens, in which the ramose tubes 

 are frequently nearly as thick as one's finger, the wall fully 2 mm. thick or 

 even thicker, and the radial canals 1 mm. or more wide. 



Dictyonal beams of the skeleton vary in different individuals from being 

 only sparsely tubercled and at places quite smooth to being profusely 



