NEMATODE PARASITES OF BIRDS 



41 



trachea, and that the assumption that the crow may act as a reservoir 

 for the turkey and chicken gapeworm is probably not well founded. 



Genus CYATHOSTOMA E. Blanchard, 1849 



Generic diagnosis — Syngamidae (p. 33): Sexes not permanently 

 joined in copula. Buccal capsule in both sexes large, thick-walled, 

 provided with 6 or 7 teeth arranged about the center at the base, the 

 teeth of 2 distinct sizes. Male bursal membrane of usual thickness 

 for strongyles in general; bursal rays slender and sometimes 

 branched; spicules long (over 400/x) and filiform. Vulva anterior, 



Figs. 47-48. — Cyathostoma bronchialis. 47, Head end. a, Side view ; b, front 

 view. 48, Male bursa. From Chapin, 1925, after Muehlig, 1884 



median, or slightly posterior to equator of body; tip of female tail 

 acute. Eggs of moderate size, operculated after deposition. 

 Type species. — Cyathostoma lari E. Blanchard, 1849. 



KEY TO SPECIES OF CYATHOSTOMA 



1. Vulva at or near the anterior third of the body 2. 



Vulva near the middle of tin- body 5- 



2. Spicules 500m long; eggs 56/t long; in Tadorna tadoma. 



Cyathostoma tadornae, p. 42. 

 Spicules 600/* long or longer, where known : eggs 80/t long or longer 3. 



3. Eggs 80/* by 40/* or 92^ by 53/*; spicules 600/u long (Skrjabin) ; in ciconiform 



birds Cyathostoma variegatum, p. 44. 



Eggs SO to 90/x long by 55 to G0/z wide or wider ; spicules 600 to 650/* h>ng__ 4. 



4. Eggs 90/* by 60//. ; spicules 600/* long; in nnseriforni birds. 



Cyathostoma bronchialis, p. 42. 

 Eggs SO/* by 55/* j spicules G50/* long; in Casuarius galeatus. 



Cyathostoma boularti, p. 44. 



