I lO VERRILL 



Cape Smith, Alaska (Murdoch, Point Barrow Expedition, 1884). 



A young specimen of acervata (U. S. Nat. Mus., No. 6082), from 

 Nazan Bay, Alaska, collected by Dr. W. H. Dall, in 1872, at low 

 tide, differs considerably from the type. This is probably due largely 

 to immaturity. The radii are 16 mm. and 48 mm. The principal 

 dorsal spines are short, capitate, and form numerous small, but con- 

 spicuous raised clusters on the disk and median zone of the rays, but 

 are lacking on the superolateral surfaces, where there are two pretty 

 regular rows of very small capitate spines and some scattered. The 

 median clusters are so crowded that they are often in contact proxi- 

 mally. The two marginal and the peractinal rows are regular, one 

 to a plate, except that the upper marginals are double distally. The 

 upper marginals are short, capitate, nearly as large as the larger dor- 

 sals ; those of the lower marginal and peractinal rows are larger, not 

 so stout, clavate or subclavate. The adambulacral spines are numer- 

 ous, subdiplacanthid ; distally they are clavate, but become longer, 

 more slender, and subacute near the mouth. The pedicellariae are 

 similar to those of the preceding form, but less numerous ; the large 

 dermal ovate-lanceolate pedicellarise are present. The apical plate at 

 the tips of the rays is rather large and the small spines are thickly 

 clustered around it. 



Ludwig (op. cit., 1900) suggested that acervata is identical with 

 A. camtschatica Brandt (op. cit., 1835). If this could be proved, the 

 latter name would have priority over all the others. But Brandt's 

 description, which was based on a colored drawing of a young or 

 small six-rayed starfish (diameter of disk one inch, length of rays 

 one to one and one-fourth inches), is far too imperfect to be of 

 much value by itself for the identification of a species of this genus. 



I have elsewhere given as good or better reasons for identifying 

 his species rather with a different one (A. midticlava) found on the 

 Siberian coast (see p. 114), but his description would apply as well, 

 also, to forms of L. epichlora. 



On the Atlantic coast this Arctic species extends southward to the 

 Gulf of St. Lawrence, at Anticosti Island, etc., and to Newfoundland 

 and the fishing banks off Nova Scotia, but not to New England. 

 It is common on the Labrador and Greenland coasts as far north as 

 north latitude 70°, at least. On the Pacific side it is found in the 

 Arctic Ocean and on the coasts of Bering Sea and the Aleutian 

 Islands, but so far as positively known to me it does not occur on the 

 southwest coa.st of Alaska. It is also known from Siberia. A 

 typical specimen of acervata, received from the U. S. National 



