148 



NORTH AMERICAN FAUNA 74 



C I 5 cm I J 



0 1^^.^ 



Fig. 96. Examples of six kinds of benthic invertebrates taken from stomachs of Pacific 

 walruses: (a) Etnu'j)hthya ruhijonnis: (b) Xcphthys sp.; (c) Echiurns cchiunis: (d) 

 Thyonidium commune; (e) Psoitis sp.; and (f) Pelonaia corrugata. (Photos by F. H. Fay) 



about 20 m to more than 100 m. They usually occur in small numbers in the 

 stomach contents, but large individuals of Nephthys sp. (Fig. 96b) may make up 

 the greatest part of the ingesta. 



Sipunculida. —The large sipunculid worm (to 23.5 cm) Golfingia mar- 

 garitacea (Fig. 97a) is a common inhabitant of sandy sediments in the Bering and 

 Chukchi seas at depths from the littoral zone to more than 300 m, where it 

 resides in a shallow burrow. This species occurs commonly in stomachs of 

 walruses taken in the Bering Strait area in spring, but usually in small numbers. 



