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NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



olive colored and hairy. Beringius kennicotti is similar in shape 

 but is slightly smaller and is not hairy. 



Three species of periwinkles, Littorina, were collected (fig. 13). 

 The periwinkles are characteristic animals of the tidal zone. They 

 are able to withstand drying for a long time, and they crawl well 

 above the waterline to rocks and seaweed where they cling in 

 clusters that often number in the hundreds. The periwinkle is 

 edible, but the flesh is not particularly tasty. Picking out the small 

 fragments of meat becomes tiresome, like eating sunflower seeds. 

 L. sitkana was by far the most abundant species (at nine stations) . 

 On Amlia Island the empty shells of this species served as homes 

 for small hermit crabs (Pagurus hirsutiusculus) . The species 

 was also found in sea-otter scats. 



Five species of Margarites were collected, most of them smooth, 

 globular, white snails. 



Four species of Nucella were collected. Nucella lamellosa 

 forms collarlike egg cases of cemented sand, often washed 

 up on the beach. 



A single sea slug, or nudibranch, Diaulula sandiegensis, was 

 collected. Other species are reported from the Aleutians. Diaulula 

 was taken by dredge from sandy bottoms at Attu and Tanaga. 



Figure 12. — Limpets, Acmaea sp., clinging to rocks in the tidal zone. 



Unalaska, July 10, 1937. 



