NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE I49 



parently new to Arctic Alaska, were also present. Metridia longa 

 goes through a daily vertical migration, except during the season of 

 long daylight, when it remains below the upper layers of water. In 

 Scoresby Sund Fjord in east Greenland, Heterorhabdus norvegicus is 

 believed to spawn in summer, for spermatophore-bearing females were 

 collected in July and August (Jespersen, 1939). 



Several unidentified bottom-dwelling species of copepods were so 

 common that they deserve mention here. The one occurring in the 

 greatest number of dredge hauls was a shield-shaped siphonostome, 

 with spherical egg sacs containing a total of about 18 large apricot- 

 colored eggs. Ovigerous females were found in August and October 

 at 420 and 175 feet, respectively. 



Another species, perhaps new, was common on the inner surface, 

 especially of larger specimens, of the sponge Echinoclathria beringen- 

 sis from Eluitkak Pass. About 50 percent of those collected on Au- 

 gust 6, 1948, were ovigerous females. Among 35 specimens examined 

 on August I, 1950, there were 8 males, 14 females carrying eggs, 

 and 3 females carrying young. 



Copepoda Parasita 



Herpyllobius arcticus Steenstrup and Liitken was found parasitic 

 on four species of polynoids : 3 out of 375 specimens of Harmothoe 

 extennata, 13 out of 215 H. imbricafa, i out of 63 Antinoe sarsi, and 

 3 out of 126 Gattyana cirrosa. Antinoe sarsi is a new host for this 

 copepod and Gattyana cirrosa may also be a new one. This species 

 of copepod occurs in east Greenland (Stephensen, 1912, 1943b), Ice- 

 land (Stephensen, 1940b), and west Greenland (Jespersen, 1939). 



Saccopsis terebellidis Levinsen was found on i out of 87 specimens 

 of the terebellid TerebelUdes stroemi Sars that were examined. It 

 also occurs in west Greenland (Levinsen, 1878), east Greenland 

 (Hansen, 1923; Jespersen, 1939; Stephensen, 1943b), west Iceland 

 (Stephensen, 1940b), and in the Pacific (Wilson, 1935) with the same 

 host but the specimen from Point Barrow forms the first record from 

 Arctic America. 



Several specimens of Choniostoma mirabile Hansen were found 

 under the branchiostegites of the shrimp Eualiis gaimardi. None of 

 the copepods exceeded 3 mm. in length and one female was only 2.1 

 mm. long. They are cream-colored and bear cream-colored eggs (Sep- 

 tember 8, 1948; August I, 1950). This copepod was described by 

 Hansen in 1886 and reported by him from east Greenland in 1923. 

 Stephensen lists it from the Kara Sea (1940b) and Davis Strait 



