NEMATODE PARASITES OF BIRDS 



45 



Morphology. — Cy at ho stoma (p. 41) : Body soft, colored bright red 

 by intervisceral fluid. Intestine spiral, much longer than body. 

 Head (figs. 56 and 58) narrower than neck. Buccal capsule with 6 

 teeth. 



Male 7 mm. long by 450//, wide. Head 200//, wide. Buccal cap- 

 sule (or aperture?) 120//, wide. Bursa (fig. 57) with 2 lobes, each 

 supported by 5 rays. Spicules slender, 650/* long. 



Female 18 to 20 mm. long by 850//, wide. Head 500//, wide. Buc- 

 cal capsule (or aperture?) 350//, wide. Body shaped like a fish- 

 hook, with a short conical tail. Anus just anterior to tip of tail. 

 Vulva prominent, 6 mm. from head end or about one-third of body 

 length from head end. Eggs 80//, by 55//,, operculated at small end. 



Life history. — Unknown; probably similar to that of Syngamus 

 trachea (p. 36). 



Figs. 5G-58. — Cyathostoma boularti. 56. Head ; side view. 57, Male bursa. 

 58, Head; front view. From Chapin, 1925, after Megnin, 1884 



Distribution. 



Paris). 



-Australia and Europe (in zoological garden, 



CYATHOSTOMA AMERICAN UM Chapin. 1925 



Host. — Buteo borealis. 



Location. — Posterior thoracic air sacs. 



Morphology. — Cyathostoma (p. 41) : Cuticle smooth, without 

 transverse striations. 



Male 12 nun. long: body (fig. 59) somewhat attenuated in ante- 

 rior fifth. Buccal capsule about as wide as deep, its internal trans- 

 verse diameter 185/x, the depth of its chitinous portion 170/*; wall of 

 capsule 25//, thick. Six or seven triangular buccal teeth, occupying 

 the entire floor of the capsule but not continued up the side of the 

 capsule in the form of ridges. The largest (lateral) teeth are about 

 57//, high. Head with circle of 6 papillae, situated 60/t behind the 

 anterior extremity, each papilla in form of rounded knob, 10//, in 



