NEMATODE PARASITES OF BIRDS 209 



;ire lacking in the male but a pair of subterminal papillae are 

 present on the ventral surface. Male with tail recurved hook-like 

 and obtusely rounded. Two filiform spicules of unequal size. 

 Female with the position of vulva variable (in posterior part of 

 body in type-species). 



Parasitic in the respiratory tract of aquatic birds. 



Type species. — Desmidocerca aerophila Skrjabin, 1916b. 



KEY TO SPECIES OF DESMIDOCERCA 



Tail of both male and female provided with terminal clump of filiform papillae; 

 esophagus 2/3 of body length ; vulva in posterior part of body. 



Desmidocerca aerophila, p. 209. 



End of male tail bare, of female tail with 2 small knobs on each side ; esophagus 

 only 1/8 to 1/9 of body length ; vulva in anterior part of body. 



Desmidocerca numidica, p. 209. 



DESMIDOCERCA AEROPHILA Skrjabin. 1916 



Hosts. — Primary: Ardea cinerea, and Phalacrocorax carbo; sec- 

 ondary : Unknown. 



Location. — Air sacs. 



Morphology. — Desmidocerca (p. 208) : Cuticle with fine transverse 

 striations. Head (fig. 277a) with 2 lips projecting forward, and 

 behind them to each side 2 submedian papillae. A small cylindrical 

 buccal cavity present. Esophagus very long, 2/3 the total body 

 length. 



Male 3.9 mm. long by 260/x wide (fig. 277&). Caudal extremity 

 (fig. 277c) recurved hook-like, bearing at its tip a cluster of spine- 

 like papillae. Spicules 660/* and 270/* long, curved in accordance 

 with the shape of the caudal extremity. No caudal papillae ob- 

 served on ventral surface of tail. 



Female 4.4. mm. long by 300/* wide. Caudal extremity (fig. 277d) 

 obtusely rounded, bearing a cluster of spine-like papillae. Vulva 

 in posterior region of body. Eggs 30/* long by 18/* wide. 



Life history. — Unknown. 



Distribution. — Asia (Russian Turkestan). 



DESMIDOCERCA NUMIDICA Seurat, 1920 



Host. — Primary : Heron cendre; secondary : Unknown. 



L.ocation. — On inner surface of air sacs. 



Morphology. — Desmidocerca. (p. 208) : Body thick-set, slightly 

 curved. Two lateral hyaline alae; lateral fields large, clearly delim- 

 ited. Cervical papillae symmetrical, situated at level of nerve ring. 

 Mouth with 2 lateral trilobed lips, each bearing 2 pairs of large 

 papillae, the most internal situated near base of interior. Buccal 



