^o 



'»T A 



,3 



C¥> 



1. PLASTIC CHECK VALVE 



2. PLASTIC DRYING TUBE 



3. TO SUCTION CONNECTION 



HEAT SOURCE 



Fioube 1. — Diagram of extraction apparatus. 



()S(i 



U.S. FISH AND WILDLIFE SERVICE 



U.S. GOVERNMENT PRINTING OFFICE : 1966 O — 795-358 



