NEMATODE PARASITES OF BIRDS 7 



a buccal capsule, thereby maintaining these groups in their ancient 

 status as on a par with the restricted Strongyloidea. This regroup- 

 ing is necessary in order to keep a definite indication of relative 

 importance. 



METASTRONGYLOIDEA, new superfamily 



Superfamndly diagnosis. — Strongylata (p. 5) : Polymyarian. 

 Usually in respiratory or circulatory tract. Bursa smaller than 

 those of other Strongylata in comparison with size of worm, and 

 with the dorsal ray often much wider than other rays, sometimes 

 several times the size of other rays; in exceptional cases the bursa 

 is lacking. Peculiar accessory structures, sometimes paired, occur 

 in some species in place of the single unpaired gubernaculum of 

 other Strongylata, and there are distinctive cutinized (or chitinized, 

 in the usual terms) structures at the place where the telamon of 

 other Strongylata occurs. 



Type family. — Metastrongylidae Leiper, 1908. 



Family METASTRONGYLIDAE Leiper, 1908 



Famihj diagnosis. — Metastrongyloidea (p. 7) : Characters of the 

 superfamily. 



Type genus. — Metastrongylus Molin, 1801. 



It has seemed advisable to create this new superfamily to balance 

 the two others in the Strongylata and to maintain in existence groups 

 of the same relative status, but as the members of this superfamily 

 have no known interest in connection with nematode parasites of 

 birds the group is not given further consideration here. 



TRICHOSTRONGYLOIDEA, new superfamily 



Superfamily diagnosis. — Strongylata (p. 5) : Meromyarian. 

 Buccal capsule absent or in some bird nematodes, present but rudi- 

 mentary. Relatively slender and sometimes hairlike forms. Bursa 

 of typical form for the suborder, not reduced in relative size. 

 Always in digestive system. 



Type family. — Trichostrongylidae Leiper, 1908. 



KKV T<S FAMILIES OF TRICHOSTRONGYLOIDBA 



1. Body frequently spirally curled. Females with ] ovary. 



Heligmosomidae, p. 8. 

 Body not spirally curled. Females with 2 ovaries 2. 



2. A small buccal capsule present, or if rudimentary (absent?) the head has 4 



papillae and epaulets Amidostomidae, p. 17. 



Head simple; no buccal capsule and cephalic structures as above. 



Trichostrongylidae, p. S. 



