CLARK: BATHYMETRICAL DISTRIBUTION OF CRTNOIDS 45/ 



Africa, inhabits the region from Morocco to the Bay of Biscay, 

 thence westward to and thruout the Caribbean & 



One of the interesting points in the distribution of this fauna 

 is that it is absent from the central East Indian region north 

 of Sumatra. Java, the Lesser Sunda Islands and the Moluccas, 

 and south of Formosa and Japan. The connection between 

 New Zealand and Hawaii is probably by way of eastern Oceania, 

 a region as yet unexplored. 



In plotting the bathymetric ranges of the species of this fauna 

 occurring in the Indian and Pacific Oceans certain bathymetric 

 altitudes of maximum abundance are noticeable, and these occur 

 in the same positions among the Japanese. Hawaiian and Indian 

 Ocean species. 



Corresponding nodes occur in the Caribbean Sea. but the 

 intervals between them are not so great. These nodes are 

 fathom> : 



Indian and Pacific Ocean? 0--50 100-1.50 300-400 750-900 1600-2000 



Caribbean Sea 100-1.50 250-300 - - -" 



On examining the nodes in the Indian and Pacific Oceans it 

 is at once evident that there is a certain regularity in their occur- 

 rence. If we should take 50 fathoms as our unit a and arrange 

 hypothetical nodes according to the ascending powers of 2 we 

 should find nodes at: 



50 a : 200 2-a : 400 2 S00 2- : 1600 2 



What we actually find are nodes approximately at : 



a: 2 (a- |): * (a + f )• or 2 - |), or 7a: * - |), 



or ISa: 2 5 [a — —). or 36a. 



