326 ANNUAL REPORT SMITHSONIAN INSTITUTION, 196 



3, figure 2, and plate 4, figure 2. Plate 1, figure 2, is published by per- 

 mission of the British Petroleum Co. 



REFERENCES 



1. EwiNG, M., Vine, A., and Wokzel, J. L. Journ. Opt. Soc. Amer., vol. 36, p. 307, 



1946. 



2. Laughton, A. S. Deep-Sea Res., vol. 4, p. 120, 1957. 



3. Thorndike, E. M. Deep-Sea Re.s., vol. 5, p. 234, 1959. 



Reprints of the various articles in this Report may be obtained, 

 as long as the supply lasts, on request addressed to the Editorial and 

 Publications Division, Smithsonian Institution, Washington 25, D.C. 



