NEMATODE PARASITES OF BIRDS 11 



A. ferns domesticux, Gallus //alius, Otis tarda, Perdix cinerea, and 

 Phasianus colchieus. 



Location. — Cecum and small intestine. 



Morphology. — Trichostronyylu.s (p. 9). Body hair-like, strongly 

 attenuated anteriorly. Mouth surrounded by 3 small papillae. 

 Cuticle longitudinally striated. 



Male 5 to 6.5 mm. long. Bursa (fig. 1) with 2 lateral lobes and a 

 small median lobe which is divided into 2 lobules by a median 

 depression on its ma rain. The ventro- ventral ray curves anteriorly 

 and is widely separated from the latero-ventral ray, which runs 

 parallel with the lateral rays to form a group of 4 comparatively 

 straight rays extending to the bursal margin; the externo-dorsal ray 

 is short, being slightly shorter than dorsal ray, and nearer to the 

 postero-lateral ray than to the dorsal ray; total length of dorsal ray 

 45/*.: it has a common stem which forms 2 branches in the posterior 

 third of its length, each branch being forked at the tip. The two 

 spicules are short (112/* long), twisted, and slightly dissimilar; there 

 is an elongate lemon-shaped gubernaculum, 63/x long. 



Female 7.3 to 7.8 mm. long. The tail terminates in a sharp cone. 

 The vulva is near the posterior end, about I of the body length from 

 the tip of the tail. The eggs are elliptical, 65 to 75/u, long by 35 to 

 42ju wide, and segmenting when deposited. 



Life history. — Development is doubtless direct, without inter- 

 mediate host. The eggs pass in the droppings, develop, and hatch, 

 the young worms reaching a stage where they will infect birds when 

 swallowed by them. Experiments on mice have suggested that 

 cutaneous infection may occur in the trichostrongyles. 



Distribution. — Europe (Germany, France, Russia), Asia (Russian 

 Turkestan), and Xorth America (collected and determined by Foster 

 from A. cin>evem domesticu*. "Washington, D. C, in 1910, but not 

 reported until the present time). 



Genus ORNITHOSTRONGYLUS Travassos, 1914b 



Synonym. — Cephalostrongylus I rwin-Smith, 1920. 



Generic diagnosis. — Trichostrongylinae (p. 8) : Slender worms, 

 attenuated anteriorly. Head swollen or inflated. Chitinous lining 

 of mouth aperture reduced. Esophagus of medium length. Male 

 with trilobed caudal bursa : posterior lobe sometimes much reduced; 

 dorsal ray typically bifurcated and each branch also bifurcated, and 

 (lie internal of these resultant secondary branches usually bifid at 

 the tip; ventral rays usually close together; externo-dorsal ray orig- 

 inating from a common trunk with the dorsal. Prebursal papillae 

 present. Spicules equal, typically trifurcated for two-thirds of their 

 length <1 ist ally. Telamon present in type species and one other; it is 



