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cays, together with Siliqua patula (Machaera costata) giving 

 the material for sand-hills. The latter mollusc is noted for 

 the thiness of its shell in comparison with those of the 

 Okhotsk sea. The flesh of this mollusc might be 

 canned. The young ones of these molluscs are a 

 favourite food of the cod-fish, the adult ones together 

 with other molluscs are eaten by sea -otters. 



That the life on the sea-shore has changed is proved 

 by the disappearance of two kinds of Cardium, which 

 are in the waters on the Islands; they are found in pieces 

 in the sand-hills and at a distance from the sea-shore 

 near the mouth of rivers, which flow into the Gavanskoye 

 lake, which was formed out of a former sea-gulf. Along 

 the shore of Kamtchatka this species also exists; on 

 Copper Isl. they are rarely found washed in by the sea. 

 Two other kinds of Cardium are remarkable for smalness 

 and thin shells. 



There are two kinds of stone-fretters found, the Saxi- 

 cava and Pholas, the latter are found in the rocks at a con- 

 siderable distance from the tidal wave and proves, that the 

 shore is raised. On Behring Isl., such facts are also known 

 about the southern part of the Kamtchatka peninsula. 



The various kinds of Tellina and Venerupis on the 

 shore (at the foot of the sand-hills), are the means of 

 building the sand-hills, in places of fine pebble-stone they 

 are cemented to the latter (doubtless on the shore, at a 

 distance from the break-water). 



Specimens of the g. Mya (M. arenaria and M. truncata) 

 are found in small quantities; on the American shore they 

 are canned. 



There are no oyesters either on the Commander Is- 

 lands or on the shore of Kamtchatka — they are replaced 

 by Anomia ephippium and are not used as food; having 

 a taste of copper (the spots on the interior of the shell 

 are of a green colour). 



The remaining biralva molluscs are only of scientific 

 interest, as they are only inhabitants of the Commander 



