NEMATODE PARASITES OF BIRDS 43 



Male 9.6 mm. long and of rather uniform thickness throughout 

 (fig. 49), brick-red in color. Cuticula transversely striated at 20/« 

 intervals. Esophagus length 640/i or 1/15 of body length. Bursa sup- 

 ported by 10 rays of which 4 are simple and G are bifurcated at their 

 apices. Spicules 50G> long; brown in color. 



Female 23 mm. long, brighter red than male. Head 90G> wide. 

 Esophagus 1.8 mm. long. Vulva near anterior third of body. Body 

 ends in a conical process (fig. 50) set at an angle to the long axis of 

 the body. Eggs 56/* long (Chatin says 0.56 mm., but this is evidently 

 an error and Skrjabin has given the figures as 56//,). 



Life history. — Unknown; probably similar to that of Syngamus 

 trachea (p. 36). 



Distribution. — Europe. 



Figs. 49-53. — Cyathostoma tadornae. 49, Male. 50, Female tail. From Chapin, 

 1925, after Chatin, 1874. 51, Cyathostoma laki. Female ; entire worm. 52, 

 Female ; head end. 53, Vulva. After Blanchard, 1849 



CYATHOSTOMA LARI E. Blanchard, 1849 



Synonyms. — Strongylus, species Siebold, 1837; Sclerosto-ma cya- 

 thostomum Diesing, 1851; Sclerostomy lari (E. Blanchard, 1849) 

 Molin, 1861a; Syngamus lari (E. Blanchard, 1849) Railliet, 1898. 



Hosts. — Lams rudibundus, L. fuscus, and Larus, species. 



Location. — Nasal and orbital cavities. 



Morphology. — Cyathostoma (p. 41) : Red worms, attenuated an- 

 teriorly. Buccal capsule (fig. 52) marked in front by an annulation. 

 Esophagus muscular, gradually widening posteriorly. Intestine 

 sinuous. 



Male 6 to 8 mm. long. Body ends abruptly at tail end. Bursa 

 said to have 6 rays, of which the middle are the most marked (no 

 satisfactory data on this feature). Spicules equal. Testis a single 

 very wide tube, sinuous anteriorly. 



Female 6 to 13 mm. long by 500/i. to 1 mm. wide; body width 

 (fig. 51) approximately uniform except for anterior third, in which 

 it diminishes anteriorly to the head. Tail with slender conical tip. 

 Cuticula finely striated. Esophagus length y 5 of body length. 

 Ovaries join capacious uteri which unite to form a vagina 2 mm. 



