28 SMITHSONIAN MISCELLx\NEOUS COLLECTIONS VOL, I28 



Hiatella association. However, the proportions of these animals 

 throughout the Arctic shelf will remain fairly constant over long 

 periods of time — for a million years or more if no great climatic 

 change takes place. Establishing a balance among the fauna of the 

 Arctic Ocean has required many millions of years, and what occurs 

 in a small locality like Point Barrow has little or no bearing on this 

 balance. If one is to have a better understanding of the evolutionary 

 processes concerned with the marine animal population, distribution 

 and deployment from the point of view of the entire Arctic shelf must 

 be considered. 



A comparison of the records obtained at Point Barrow with those 

 of other investigators of the Arctic Ocean shows that such factors as 

 climate, vegetation, geology, ice, currents, temperature, salinity, light, 

 oxygen, tides, wind, and storms are quite uniform for the entire area 

 of the shelf. Therefore a marine animal adapted to one place on the 

 shelf is adapted to all regions of the shelf. If it can be proved that ani- 

 mals found in one locality of the Arctic shelf are found in all similar 

 localities, then a knowledge of distribution is most important to our 

 understanding of how the fauna of the Arctic shelf became established 

 and what to expect in future evolutionary trends. 



The greatest merit of the Point Barrow investigation has been its 

 contribution toward verifying these theories. The distribution of all 

 adapted forms is proving to be quite uniform, although many more 

 localities around the basin need thorough investigation. An intensive 

 survey of the Continental Shelf bordering the Laptev Sea would be 

 of value equal to the one done at Barrow. 



If a comparison can be made with Scandinavian collections in order 

 to eliminate uncertainties regarding names, a table could be made 

 showing species common to both Point Barrow and the North Pacific 

 and those common to Point Barrow and the North Atlantic. Such a 

 table would be of great value in furnishing evidence of the rates of 

 distribution between the three areas. It would help to answer such 

 questions as the following: 



1. Does the continuous flow of ocean water northward through Bering Strait 

 inhibit the distribution into the North Pacific? 



2. Is the rate of distribution into the Arctic from the Atlantic greater than 

 from the Pacific into the Arctic? 



3. Is there any distribution of strictly Arctic animals from the polar regions 

 into the North Atlantic? 



4. Is there any evidence that ship bottoms play a part in distribution? 



5. Is there evidence to show that it is easier for distribution to proceed from 

 a warmer to a colder habitat or vice versa? 



