NEMATODE PARASITES OF BIRDS 331 



Male 13 mm. long by 220yi wide. Esophagus 518/i long. Caudal 

 extremity (fig. 397c) tapering to a tine point. Right spicule (fig. 

 3976) 250/u. long, slightly curved, its dorsal surface convex, its ventral 

 concave; the ventral surface has a gutter which probably facilitates 

 the movement of the long spicule in gliding through it, thus serving 

 as a gubernaculum. Left spicule 600^ long, filiform, the posterior 

 extremity pointed. Arrangement of caudal papillae unusual ; 5 pre- 

 anal papillae of which there are 2 symmetrical pairs and a fifth 

 papilla isolated on the right side with no corresponding papilla on 

 the left ; 7 postanal papillae, 2 of which form a symmetrical pair 

 near the caudal extremity, the other 5 having a submedian and very 

 asymmetrical arrangement and being of unequal size. In addition 

 to the papillae, there are other asymmetrical formations, the char- 

 acter of which is undetermined, in the lateral fields posterior to the 

 cloacal aperture. 



Female 14 mm. long by 320^ w T ide. Esophagus 765/a long. Anus 

 510/* from end of tail. Vulva in posterior part of body. Eggs 46/x 

 by 29/x. 



Life history. — Unknown; probably involves intermediate stages in 

 other hosts. 



Distribution. — South America (Paraguay). 



(70XYSPIRURA) HETEROCLITA (Molin, 1860) Ransom, 1904 



Synonyms. — Spiroptera heteroclita Molin, 18606/ Spiroptera cracis 

 Molin, 1860 6. 



Hosts. — Primary: Crax urumutum (=Nothocrax urumutum) ; 

 secondary : Unknown. 



Location. — Under nictitating membrane. 



Morphology. — Oxyspirwra (p. 321) : Body attenuated anteriorly, 

 apex truncate. Cuticula with fine transverse striations. Mouth or- 

 bicular, large, without lips. 



Male 12 mm. long by 300/i wide. Head without membranes. Tail 

 awl-shaped, sharply pointed, curved into a hook, without caudal alae. 

 Two pairs of postanal papillae. Preanal papillae not described. 

 Spicules unequal, the one short and thick, the other filiform, half as 

 long as the body. 



Female 55 mm. long by 400/a wide. Head with 4 short, semilunar 

 membranes, arranged in the form of a cross. Tail gradually attenu- 

 ated, awl-shaped, with obtuse tip. Anus remote from tail end. 

 Position of vulva not determined. 



Life history. — Unknown; probably involves intermediate stages in 

 other hosts. 



Distribution. — South America (Brazil). 



