PSYCHE 
A JOURNAL OF ENTOMOLOGY 
Established in 1874 
Vol. 64 December, 1957 No. 4 
TABLE OF CONTENTS 
The Presence of a Peritrophic Membrane in Some Aquatic Hemiptera. 
M. C. Parsons . . .117 
The Food Pump of Pelocoris and Comparative Studies on Other 
Aquatic Hemiptera. E. P. Marks 123 
The Esophageal Valve of Some Aquatic Hemiptera. M. C. Parsons 135 
Index to authors 149 
Index to Subjects 151 
