28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



GORGODERIDAE 



In the Gorgoderidae, commonly parasitic in frogs, the intermediate 

 hosts known at present are mostly Odonata, the role of intermediate 

 host here being combined with the role of food for frogs. One of the 

 Decapoda, a crayfish, is the host for a gorgoderid parasitic in fish. 



HALIPEGIDAE 



In the Halipegidae, the only reported life history involves the 

 Odonata as intermediate hosts, the primary hosts here being frogs. 



TROGLOTREMATIDAE 



In the Troglotrematidae the only known life history, that of the 

 human lung fluke, involves several species of decapods, crabs being 

 known hosts and crayfish probable hosts. 



HEMIURIDAE 



In the Hemiuridae, which are fish parasites, all known intermediate 

 hosts are crustaceans, those for two flukes being copepods and those 

 for one fluke being decapods. 



DICROCOELIIDAE 



The one dicrocoelid with a known life history utilizes an amphipod 

 as an intermediate host, the primary hosts being fish. 



BRACHYCOELIIDAE 



The one brachycoelid with a known life history has a trichopteran 

 as an intermediate host, the primary hosts being amphibians. 



FAMILY UNCERTAIN 



The three flukes of uncertain relationship for which we know 

 primary as well as secondary hosts, and not merely secondary hosts for 

 larval stages, all have carnivores as primary hosts and crabs as sec- 

 ondary hosts. 



ARTHROPODS AS INTERMEDIATE HOSTS OF 

 NEMATODES 



In listing the nematodes having intermediate stages in arthropods, 

 no attention has been paid to nematodes listed only as nematodes 

 without reference to whether the nematodes were mature or immature. 

 Nematodes occurring consistently as larvae in insects may be the 



