JAPANESE ASTEEOIDEA. 407 



one from 3257, near Unimak, Aleutian Islands. The specimens from 

 Kadiak Island and Slielikof Strait are frankly not typical, but appear to be 

 intergrades with cdascensis. Japanese specimens are variable and not quite 

 typical. The specimens from Matsusliima, in proportion to length of ray, 

 have fewer and hence longer marginals, wliich are wide. All the gi'anuki- 

 tion is low, coarse, and very compact and the adambulacral spinelets are 

 veiy heavy in proportion to length, those on outer half of j)late being 

 gianuhform. The wide marginals are duplicated in an Alaskan specimen 

 from station .S258, there being also a more typical specimen from the same 

 dredge haul. The enlarged actinal intermediate spinelets on both Alaskan and 

 Japanese specimens (of which I have examined a number) are quite varia- 

 ble, sometimes being absent, while equal-sized examples have them. Post- 

 adambulacral fascioles are not always evident. 



" It ap^x^ars as if this species, spreading south along the Alaskan coast, 

 had changed into a form with narrow superomarginals, having less granuli- 

 form armature on the actinal surface, and less compactly placed granules on 

 the abactinals. Along the Asiatic side the development has been toward fewer 

 and broader superomarginals, with more compact abactinal granules, and an 

 accentuation of the granuliform character of the actinal armature. The 

 Japanese form has departed less from the type than has the British Colum- 

 bian. 



" This species is the north Pacific and Atlantic representative of Fs, 

 discus Sladen (from Messier Channel, between Chile and Wellington Island),, 

 to which it is closely related. It may be that Ps. imlcher Ludwig (Gala- 

 pagos to southwest of Acapulco), founded on very small specimens, is the 

 connecting link between the two forms. 



" A few words concerning the name adopted may be in order. In the 

 Museum of Comparative Zoology are tlu*ee specimens of ' Astropecten parelii ' 

 from Nonvay, presented by Professor Sars in 1852. These agree very well 

 with the original description and figm-es of Düben and Koken. There are 

 no differences of importance between these specimens and an example of 

 PseudarcJiasfer inUrmedim from off Rhode Island. Similarly, the Norwegian 

 specimens l^long to the same species as the Alaskan. There is far more 



