144 ECHINODERMS OF THE BRITISH ISLES 



a very considerable size, up to 35 cm. R. Colour in life yellowish, 

 orange, reddish, or greenish. 



It is a very voracious animal, which feeds on all sorts of larger 

 marine organisms, living or dead : fishes, crustaceans, echino- 

 derms, but especially molluscs ; it is rei^orted as doing harm on 

 the oyster banks. At Plymouth it appears to feed mainly on 

 Pecten opercularis. 



It is very apt to throw off its arms when hurt or otherwise in 

 poor condition ; they regenerate very easily. But it does not 



Fig. 82. — Marthasterias glacialis. Somewhat reduced in size. 

 (From Danmark's Fauna.) 



propagate by self-division, as does the somewhat similar, more 

 southern, species Coscinasterias tenuispinus. 



The larva very much resembles that of Asterias rubens ; the 

 characters by which to distinguish these two larval forms are 

 unknown. The breeding season is the summer ; in the Medi- 

 terranean it appears to have two yearly breeding seasons, summer 

 and winter. 



In British seas this species occurs all round the West coast, 

 and to Plymouth on the South coast ; from the British North Sea 

 coasts it is not recorded, while elsewhere it has been recorded 

 both from the northern and southern j^art of the North Sea. It 

 is elsewhere distributed from Finmark and Iceland down to the 

 Azores and the Cape Verde Islands, and also the Mediterranean. 



