II. 



ON SUCCESSION IN THE SHELL-HEAPS OF THE ALEUTIAN 



ISLANDS 



BY 'W. H. DALL. 



The notes of which this paper is the result were made while engaged 

 in a hydi'ographic and geographical reconnaissance of the Aleutian Islands, 

 under the auspices of the United States Coast Sm-vey. They were made 

 at enforced intervals of leisure, occasioned by weather which would not 

 permit the ordinary surveying operations of the party to be carried on; a 

 circumstance which will explain the limitations by which our observations 

 were necessarily curtailed. Notwithstanding this limitation, however, it is 

 believed results of value have been obtained. 



The character of the islands is tolerably well known, and a sketch of 

 them, which gives all the details necessary for a comprehension of this 

 paper, will be found accompanying the paper on the distribution of the 

 Indian tribes on the general map of Alaska Territory. 



Their topography, with few exceptions, is higli and rugged ; their 

 shore-lines very irregular, and mostly rocky ; their vegetation rich and 

 abundant, but confined to herbaceous plants and small species of Vaccinium 

 and Salix, none as a rule attaining to a greater height than four feet, and 

 often creeping along the surface of the soil. The climate is moist and not 

 cold, but inclement from the abundance of cloudy weather, fog, rain, and 

 at certain seasons the prevalence of severe gales. The harbors are rarely 

 closed by ice, and then only for a few days or until the first fresh breeze. 



