NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE 1 57 



A female with a developing marsupium was taken on September 30, 

 1949. 



Anonyx nugax (Phipps) was not observed at all during the summer 

 of 1948 but was taken throughout the summer of 1949 and the winter 

 of 1949-50. Never especially abundant except during the third week 

 in September 1949, when thousands were thrown ashore, it was 

 dredged from early August until October 14, 1949, at depths of 120 

 to 522 feet. In the winter and spring it was taken (by means of 

 screen traps through the ice) regularly but sparingly except on Febru- 

 ary 28, 1950, when hundreds of small ones were taken, and on March 

 10, 1950, when both young and adults were numerous. One ovigerous 

 female, with eggs 1.3 mm. in diameter, was taken on August 8, 1949, 

 at 120 feet. Freshly molted females washed ashore on September 22, 

 1949, had well-developed ovaries that showed through as peach or 

 orange masses, and several females between 32 and 37 mm. long had 

 developing marsupiums. This species is new to Arctic Alaska. 



An ovigerous female Paronesimus barentsi Stebbing washed ashore 

 on October 5, 1949, and another taken on August 21, 1949, had, in 

 addition to three young amphipods, a male and female copepod in 

 its marsupium. This species has been known only from west of Nova 

 Zemlya. 



Several species of Pseudalibrotus, difficult to distinguish because 

 of their similarity and small size, were taken. P. hirulai Gurjanova, 

 which has reddish-brown eyes, came from plankton tows and the fine 

 gravel near shore. P. littoralis (Kroyer), a pale-gray species with 

 cerise eyes and coral-colored eggs, may be found in the gravel near 

 shore, where it goes in and out of the interstices, feeding voraciously 

 on any disabled animals that it can find, such as arrow worms, shrimps, 

 amphipods, and even fish. It is a hardy species that can survive low 

 salinity and abrupt changes of temperature. 



The only specimen of Onisimus normani Sars collected was an 

 ovigerous female from 60 feet. This amphipod was pinkish white, 

 and the large, oval eggs were orchid color, turning yellow in pre- 

 servative. 



Onisimus affinis Hansen was dredged from 120 to 438 feet, taken 

 through the ice on March 9, 1950, at 135 feet, and in a fish trap on 

 February 7, 1950, at 7 feet. In the latter specimen the ostegites and 

 thoracic appendages were translucent white, the caudal appendages 

 and the thorax and abdomen pinkish buff, and across the posterior 

 margin of each segment was a transverse band of bright orange red. 

 The antennules were tinged with the same color and the eyes were a 

 shining orange red. A specimen that washed ashore on September 19, 



