NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE I4I 



Alaska, washed ashore on October 17, 1949 (9 specimens), and 

 August 10, 1950 (3 specimens). 



Arenicola glacialis Murdoch is obviously very abundant for it 

 vi^ashed ashore in great numbers after certain storms, especially in 

 the open season of 1949. Two were dredged from the gravel near 

 shore at a depth of 10 feet. This species is reddish, sometimes with 

 a greenish prostomium and greenish caudal end. When preserved it 

 often turns the preserving fluid a dark green and the worm itself 

 becomes almost black. 



Five species of maldanids, all new to Arctic Alaska or the western 

 Arctic, and one new to Arctic America, were dredged. Praxillella 

 practermissa (Malmgren) was taken from seven stations in the mud- 

 covered rubble zone in the fall and winter of 1949-50. Since it had 

 not been taken in hauls from similar depths in 1948, it had obviously 

 been transported to the rubble zone from the mud zone by the storms 

 in the late open season of 1949. 



Six specimens of the beautiful sabellariid Idanthyrsus armatus 

 Kinberg, which is new to Arctic Alaska, were dredged from 28, 150, 

 and 420 feet. The predominating colors are red and white, with 

 golden setae on the head structures. 



The cosmopolitan detritus-feeding Sternaspis acutata (Ranzani) 

 appeared in the dredge hauls from 10, 132, and 148 feet. 



Two species of pectinariids, both new to the western Arctic, were 

 taken: Pectinaria granulata (Linnaeus) (53 specimens) from 22 to 

 741 feet; and P. hyperborea (Malmgren) (19 specimens) from 118 

 to 741 feet. Both were largely from stations characterized by mud 

 bottoms. 



Four species of ampharetids, three new to Arctic America and 

 one new to Arctic Alaska, were dredged. The most interesting of 

 these was Asabellides sibirica (Wiren) from 22 feet on July 26, 1948, 

 (3 specimens). It lives in a mud tube with a tough lining. The tubes 

 were from 100 to 140 mm. in length. One worm was 45 mm. long. 



In number of species the terebellids equaled the syllids and poly- 

 noids, for each family was represented by 1 1 species. All the species 

 of terebellids are new to Arctic Alaska and several are new to 

 Arctic America. 



A single specimen of Amphitrite groenlandica Malmgren was 

 dredged from 295 feet and one specimen of Leaena abranchiata 

 Malmgren was taken from 150 feet. Amphitrite cirrata Miiller was 

 represented by 14 specimens from no to 420 feet, 5 coming from 

 125 feet. 



