SHALLOW- WATER STARFISHES III 



Museum (No. 7630), was found on the beach at Cape Smith, 

 Alaska, October, 1881, by Mr. Murdoch (Point Barrow Expedi- 

 tion). The young specimen described above was from Nazan, 

 Alaska (W. H. Ball). 



Ludwig (op. cit., 1886, p. 287) refers to A, acervata as follows: 



" Of this species, which has become known through Stimpson, 

 there are a number of examples, the largest of which measures 

 17.5 mm. The specimens come from Bering Strait, from a depth of 

 from five to fifteen fathoms, and according to their exact localities 

 are divided as follows : Two specimens from Lorenz Bay ; one full- 

 grown and one quite young specimen from Emma Harbor, Plover 

 Bay; one specimen from St. Matthew's Island; one specimen from 

 northwest of St. Matthew's Island, at a depth of twenty-five 

 fathoms ; one specimen from St. Paul's Island ; three specimens with- 

 out definite locality, from a depth of from twenty-three to twenty- 

 five fathoms. All the foregoing specimens are six-armed; and fur- 

 ther, one five-armed specimen from St. Paul's Island." 



It seems probable that Stimpson's A. acervata is not specifically 

 distinct from the North Atlantic and Arctic A. polaris. I have 

 compared typical specimens of it with specimens of A. polaris from 

 Labrador and found a close agreement, so that there can scarcely be 

 a doubt of their identity, though they may be separated as geographi- 

 cal varieties. In that case the North Atlantic form should be called 

 Asterias acervata borealis (Per.). 



Stimpson's description applies fairly well to some specimens of 

 the same size from the Atlantic, except in one particular. He 

 mentions the occasional occurrence of stout, serrate major pedicel- 

 larise in the lateral channels, evidently referring to the form char- 

 acteristic of the various species of Pisaster, and also found in 

 Leptasterias epichlora alaskensis Ver. and var. subnodulosa Ver. I 

 have not been able to find such pedicellariae on the Atlantic A. polaris. 

 Therefore, it is not unlikely that some of Stimpson's specimens 

 belonged to subnodulosa, which is also six-rayed and acervate and 

 often has much resemblance to his A. acervata. Moreover, it is a 

 very common littoral variety on the Alaskan coast, and Stimpson 

 could hardly have failed to have had it in his possession. But in 

 other respects his description certainly does not apply to the latter. 



