NEMATODE PARASITES OF BIRDS 9 



Genus TRICHOSTRONGYLUS Looss, 1905 



Generic diagnosis. — Trichostrongylinae (p. 8) : Small and 

 slender worms. Head small, with 3 small lips and with nodular or 

 punctiform papillae. Esophagus long. Cervical papillae lacking. 

 Male with caudal bursa with large lateral lobes, without well de- 

 veloped median lobe, each lateral lobe with G supporting rays; the 

 dorsal ray short and cleft at the end. Spicules short, spoon-shaped 

 or spatula-shaped, with a twisted appearance due to the arrangement 

 of some ridges on them; the proximal end of each spicule thickened 

 by a disk-like process towards one side. Gubernaculum wedge- 

 shaped. Prebursal papillae rudimentary or absent. Female with 

 vulva in posterior half of body, slit-shaped or crescentic, surrounded 

 by somewhat protruding chitinous lips. Uteri divergent; ovejectors 

 well developed. Postanal portion of body relatively short, with a 

 pair of small caudal papillae (?) near the tip. Eggs of moderate 

 size, thin-shelled, segmenting when deposited. Parasitic in the 

 duodenum, more rarely the stomach, of herbivores, rodents, man and 

 birds, and in the ceca of birds. 



Type species. — Trichostrongylus retortaeformis (Zeder, 1800) 

 Looss, 1905. 



KEY TO SPECIES OF TRICHOSTRONGYLCS 



1. Dorsal ray of bursa unbroken until near tip where it divides into 4 short 

 digitate processes; gubernaculum in profile the shape of a Turkish slipper; 



vulva J,; of body length from tail end Trichostrongylus pergracilis, p. 9. 



Dorsal ray split into 2 branches in the posterior third of its length, each 

 branch being forked at tip; gubernaculum elongate lemon-shaped; vulva 

 V7 of body length from tail end Trichostrongylus tenuis, p. 10. 



TRICHOSTRONGYLUS PERGRACILIS (Cobbold, 1873) Raalliet and Henry, 1909 



Synonym. — Strongylus per gracilis Cobbold, 1873. 



Host. — Colinus virginianus and Lag opus scoticus. 



Location. — Ceca. 



Morphology. — Trichostrongylus (p. 9) : Body hair-like, attenu- 

 ated anteriorly. Mouth with 3 minute lobes. Transverse striation 

 distinct, especially in anterior portion of body where it gives the 

 worm a serrate outline as viewed under the microscope. Longitu- 

 dinal striations not seen. 



Male G to 8 mm. long. Bursa (figs. 2 and 3) with 2 lateral lobes 

 and a small sharply pointed median lobe. The latero-ventral ray 

 ci lives anteriorly and the externo-lateral ray slightly posteriorly so 

 that the tips of these 2 rays are separated by a considerably greater 

 interval than that beween the tips of the 3 lateral rays. Externo- 

 dorsal rays (50^ in length) are longer than the dorsal ray (36/x in 



