REPORT ON TIIE ASTEROIDEA. 



223 



Chorology of the Genus Psilaster. 



a. Geographical distribution : — 



Atlantic : Four species between the parallels of 75° N. and 40° S. 



Psilaster andromeda, off the Scandinavian coasts, and off the 

 British Islands, extending to the Bay of Biscay. Psilaster cassiope 

 and Psilaster patagiatus, off the Cape Verde Islands. Psilaster 

 acuminatus occurs in the extreme South Atlantic, in Simon's Bay, 

 Cape of Good Hope. 



Pacific : Two species between the parallels of 40° N. and 50° S. 



Psilaster gracilis, off Japan. Psilaster acuminatus, off Australia 

 and New Zealand. 



/9. Bathymctrical range: Shallow water to 1875 fathoms. 



Four species, viz., Psilaster cassiope, Psilaster patagiatus, Psilaster andro- 

 meda, and Psilaster acuminatus are found in the Littoral zone ; and the two 

 last named pass through the Continental zone and extend into the Abyssal zone. 

 Psilaster gracilis is confined to the Abyssal zone. 



Greatest range of one species : Psilaster acuminatus, shallow water to 

 950 fathoms. 



y. Nature of the Sea-bottom : Two species, Psilaster acuminatus and Psilaster 

 gracilis, are found on Blue mud, the former also occurring on Green mud in 950 

 fathoms. Psilaster andromeda inhabits a clay bottom, sometimes sandy. 



Cliorological Synopsis of the Species. 



