PRELIMINARY CHECKLIST OF THE ODONATA OF THE IGUAZU NATIONAL PARK, MISIONES PROV., ARGENTINA — 106 spp. are listed, collected in the Park and its surroundings during Apr. 1974, Oct.-Nov. 1975, Dec. 1978- -March 1979. 46 of these (asterisked) are not listed in the lists of F.C. FRASER (1947- -1948, Acta zool. lilloana 4: 427-461; 5: 47-67) and D.R. PAULSON (1977, in. S.H. Humbert, Ed., Biota acuatica de Sudamerica austral, pp. 170-184, San Diego St. Univ.).