JAPANESE ASTEROIDEA. 179 



Bipaster in wliicli tlie gonads are not described." 



This is one of the best characterised species of the genus on 

 our coasts and is not uncommon in C3rtain localities at certain 

 depths, its most characteristic feature being the presence of a 

 series of 3-9 or 10 flattened spines on the superomarguials. As 

 to the unpaired interradial marginals mentioned by de Loriol, 

 my own observations agree with those of Döderlein, and in 

 none of the specimens that have passed throTigh my hands 

 were they present. A careful examination of the figure given by 

 DE LoRiOL also fails to bring them to light. It is true th at in 

 one or two of the interradii, a wedge shaped superomarginal is 

 represented in the figure, bub its position is easily seen not to be 

 strictly interradial. Again with regard to the armature of the 

 first adambulacrals, which is emphasized by de Loriol as a very 

 characteristic feature of the species, it must be remarked that a 

 similar comb-like arrangement of the spines can be observed in 

 several other species of the genus. It may, however, be admitted 

 that it is somewhat more conspicuous in the present species, 

 owing to the relative thickness of the spines concerned, and the 

 strict regularity of their arrangement. 



Radial ratio. — The radial ratio of this species appears to be 

 less subject to variation than in those described above, although 

 it must be borne in mind that the range of the variation 

 may be found to be wider with the study of more numerous 

 specimens. The following table gives a clearer idea of the radial 

 ratio than any general descriptions can. 



