134 
Psyche 
[December 
and the Corixidae, these two latter groups then pursuing 
diverging lines of specialization. Investigation of the pumps 
of various genera within these three families should pro- 
vide valuable information concerning these relationships. 
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China, W.E. 
1955. The evolution of the water bugs. Bull. Nat. Inst. Sci. India, 
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Griffith, M.E. 
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man Rhamphocorixa acuminata (Uhler) (Hemiptera, Corixidae). 
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Marks, E.P. 
1958. A comparative study of the foregut of several aquatic Hemiptera. 
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