62 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



The stomach is very spacious, filling the entire disk and reaching into the base of 

 the rays. It has a single chamber, the hepatic coeca entering the dorsal part of each 

 lobe The intestinal coecum consists of two short thick lobes. The food is evidently 

 ingested entire, as the stomach was full of small gasteropods. The ampullae are 

 rather large, strictly simple, not bilobed, and the tube-feet are bisenal. The radial 

 nerve fold and circumoral pentagon are rather thick. 



Type.— Cat. No. E, 1418, U.S.N.M. 



Type-locality.— Station 4792, off Cape Monati, Bering Island; 72 fathoms, 



Distribution.— Southern Bering Sea, from the Commander Islands to Unimak, 

 and north to 57°; south along the Alaskan coast to Kasaan Bay, Prince of Wales 

 Island; 42 to 121 fathoms, on gravel, black and gray sand and green mud. Tem- 

 perature range typically 37.3° to 39.8° (an exception station 4292). 



Specimens examined. — Thirty-eight. 



Specimens of Pedicellaster magisier examined 



Sta- 

 tion 



3223 

 3224 

 3257 

 3258 

 3488 

 3500 

 3675 

 4243 

 4292 

 4786 

 4791 

 4792 



Locality 



Between Unalaska and Unimak.. 

 do 



North of Unimak Island - 



do 



Bering Sea, 57° 05' N., 173° 47' W 



Bering Sea, 66° 02' N., 169° 30' W 



Off Karluk, Kadiak 



Kasaan Bay, Prince of Wales Island, Alaska. 



Shelikof Strait, Alaska . 



OflMedni, Commander Islands 



Off Cape Monati, Bering Island 



....do 



Depth 



56 



121 



81 



70 



106 



121 



110 



42-47 



102-94 



54 



76 



72 



Nature of bottom 



Black pebbles 



Black sand; gravel 



Gray sand; gravel 



Black sand; gravel .. 

 Green mud; gray sand 

 Fine gray sand; gravel. 



Green mud 



do 



Mud; fine sand 



Green sand.. 



Rocky 



Pebbles 



Bottom 

 temper- 

 ature 



39 



38.7 



39 



39 



37.3 



38.6 



39 



49.1 



39.8 



Num- 

 ber of 

 speci- 

 men 



Collection 



U.S. Nat. Mus. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Albatross, 1903. 



Do. 

 Albatross, 1906. 



Do. 



Do. 



Remarks. — Pedicellaster typicus, from the northern part of the North Atlantic 

 and adjacent Arctic Ocean seems to be rather further removed from magister than are 

 either of the Pacific subspecies. It is a small form, the largest specimen recorded by 

 Danielssen and Koren " being but 42 mm. in diameter, while most of their specimens 

 ranged from 10 to 23 mm. in diameter. The type of magister is 170 mm., and many 

 are over 100 mm. in diameter. According to Danielssen and Koren, true typicus is an 

 Arctic form which extends southward on the European coast to Sognefjord, Norway. 

 It is found on the Murman coast; at Nova Zembla, Spitzbergen, Jan Mayen; in 

 Barents Sea; Kara Sea; on the west side of the Taimur Peninsula (the northeast 

 border of the known range). On the American side it has been taken as far south as 

 42° (Verrill, 1895), and north through Davis Strait as far as Discovery Bay in Grinnell 

 Land, 81° 41' north latitude (Duncan and Sladen). 



Verrill, 1914 (p. 203), has recorded a small example from Icy Cape, Alaska, well 

 within the Arctic Ocean. This specimen (No. 6123, U.S.N.M., 10 to 15 fathoms, mud 

 and sand, W. H. Dall, 1874) can not now be found. If it is true typicus (and not a 

 young specimen of magister), the range is therefore circumpolar, and intergradation 



« Asteroidea (Norwegian North Atlantio Expedition, 1876-1878), 1884, p. ! 



