176 



BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



that length; margin crenulated. Lateral lips (fig. 246 g and h) 

 large, thick, with 3 prominent teeth on anterior border, and on the 

 external surface midway is a horizontal row of 3 very small papillae. 

 Dorsal and ventral lips with sharp-edged projecting central prom- 

 inence and 2 lateral rounded unarmed latered lobes. Cuticle forms 

 collar around base of lips. 



Male size differs in different birds, the average being 8 mm. long 

 by 31G> wide, the maximum 12 mm. long by 350/a wide. Caudal 

 alae slightly asymmetrical. Ventral surface of tail (fig. 246a) 

 covered with long rectangular plates arranged longitudinally. Ten 

 pairs of caudal papillae and 1 unpaired papilla on anterior margin 

 of cloacal aperture; 4 pairs are preanal and 6 pairs postanal. Clo- 

 acal aperture about 350/x from posterior end. Spicules unequal. 



Fig. 246. — Habronema incerta. a, Male tail; b, eggs; c, female tail; d. 



TRANSVERSE SECTION OP ANTERIOR END; e, ANTERIOR END; f, FEMALE, SHOWING 

 POSITION OF VULVA ; g, FRONT VIEW ; h, DORSO-VENTRAL VIEW OF HEAD. AFTER 



Smith, Fox, and White, 190S 



Female size varies in different birds, the average being 14 mm. 

 long by 45G> wide, the maximum 20 mm. long by 600/x wide. Anus 

 (fig. 246c) about 200^ from posterior end. Vulva (fig. 246/) difficult 

 to find, described as in the first third of length of body (figure 

 shows it behind the first third, but anterior to the middle of the 

 body). Eggs (fig. 2466) 34 to 42^ long by 16 to 20^ wide. 



Life history. — Unknown; probably involving insects as interme- 

 diate hosts. 



Distribution,— North America (United States (Zoological Gardens, 

 Philadelphia, Pennsylvania)). 



HABRONEMA LEPTOPTERA (Rudolphi. 1819) Seurat. 1914a 



Synonyms. —Spiroptera leptoptera Rudolphi, 1819; Filaria lep- 

 toptera (Rudolphi, 1819) Schneider, 1866. 



Hosts. — Primary: Accipiter nisus, Astur nisus, A. palumbarius, 

 Buteo vulgaris, Circus aeruginosus, C. cineraceus, C. cyaneus, C. 



