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The molluscs of the Commander Islands are descri- 

 bed by the American naturalist Dall (77 kinds according 

 to the latest articles in 1899) a list of the molluscs of 

 the Commander Islands, was given by N. Grebnitzky. 



The earth molluscs have a very thin shell (Limax and 

 Arion are very rare). 



The craw-fish fauna notwithslanding its economical 

 importance is very unsatisfactory explored on the Com- 

 mander Islands; the decapoda are studied, slightly but 

 the most important groups the Amphipoda, Isopoda, 

 Ostracoda, are not spoken of at all; with the exception 

 of a few accidental definitions. The existing collections 

 are waiting to be elaborated. Of the small forms, for 

 instance the Copepoda is nowhere mentioned and is espe- 

 cially important for the plankton. This item will most 

 likely not be finished for a long while yet. The study of 

 it must absolutely be done on the spot, but the existing 

 literature is so extensive and expensive, that it is too 

 difficult for any observer. But the naturalists visiting the 

 Islands did not attend to this species and solely occupied 

 themselves with the vertebrata. But how interesting to 

 science this class might become, is proved by Tcherniav- 

 sky's small work of Mysidae. In speaking of the parasite 

 craw-fish species, only the parasites of whales are men- 

 tioned. 



Large decapoda are not found on the Island and they 

 are represented by very small specimens. They are eaten 

 by the cod-fish and the Chiridae. But there are numerous 

 specimens (3) of craw-fish-hermits, — also small, which 

 serve as food to the fish near the shore. The sea, as 

 well as the river Mysidae come in shoals and in the 

 rivers they are eaten by the trout, in the sea mostly by 

 Baty master, which again are good food for the cod-fish. 

 Of crevets, there are no less than 8 species shown, which 

 are also eaten in quantities by all sea-fish. 



Of the small Isopoda — the Munna and Yanira species 

 are found near the beach; the larger ones, such as the 



