42 BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



5. Male unknown ; female small, up to 13 mm. long, in orbital cavity of Larus 



ridibundus Cyathostoma lari, p. 43. 



Male known ; female up to 20 mm. long or longer 6. 



6. Spicules 490// long; gubernaculum 67//. long; female up to 30 mm. long; in 



thoracic air sac of Buteo borealis Cyathostoma americanum, p. 45. 



Spicules 660 to 720//. long ; gubernaculum 92/t long ; female up to about 20 mm. 

 long; in trachea of Coscoroba coscoroba Cyathostoma coscorobae, p. 47. 



CYATHOSTOMA BRONCHIALIS (Muchlig. 1884) Chapin, 1925 



Synonym. — Syngamus bronchialis Muehlig, 1884. 



Hosts. — Anas boschas domestica, Anser cinereus domesticus, and 

 Cascara cascara. 



Location. — Larynx, trachea, and bronchi, as adults; also, appar- 

 ently accidently, in the abdominal air sacs. 



Morphology. — Cyathostoma (p. 41) : Very similar to S. trachea 

 (p. 34), but larger and less firmly united in copula (head, fig. 47). 



Male 8 to 12 mm. long by 200 to 600/* wide. Bursa (fig. 48) inte- 

 gral, not incised, with all the rays tending to be parallel on each side 

 of the dorsal ray. The 2 ventral rays are close together; the short 

 externo-lateral ray is alone and midway between the postero-lateral 

 and the dorsal rays ; the dorsal ray has a thick stem which bifurcates 

 to form 2 branches, each of which bears a knob near its base and 

 a small branch near its tip. There are 2 slender spicules, 600/a long, 

 slightly hooked at their distal extremities. 



Female 20 to 30 mm. long (30 to 40 mm., according to Hayem) 

 by 1 to 1.5 mm. wide. The conical tail end bears a pointed process. 

 The somewhat prominent vulva is about one-third of the body length 

 from the head end. Eggs 80 to 90//, long by 60/* wide and provided, 

 according to Railliet, with a single polar operculum. 



Life history. — Similar to that of Syngamus trachea (p. 36). Rail- 

 liet found that embryos developed in the egg in 2 weeks. On hatch- 

 ing the tail end of the worm emerged first. An attempt to infect 1 

 adult duck and 1 adult goose failed, but after feeding eggs to 3 geese 

 2 to 3 months old, 1 female worm developed in 1 goose. 



Distribution. — Europe (France and Russia) and Asia (Turkestan 

 and Japan). 



CYATHOSTOMA TADORNAE Chatin, 1874 



Synonyms. — Sclerostoma tadornae (Chatin, 1874) Linstow, 1878; 

 Syngamus tadornae (Chatin, 1874) Railliet, 1898. 



Host. — Tadorna tadorna. 



Location. — Trachea. 



Morphology. — Cyathostoma (p. 41): Buccal capsule with 2 

 pharyngeal teeth at its base (Chapin regards this as an error of 

 observation in a worm examined from the side only, and thinks there 

 are probably 6 or 7 teeth ) . 



