NEMATODE PARASITES OF BIRDS 27 



externo-dorsal ray is short and massive, originates directly at the 

 tip of the tail, and does not reach the bursal margin. The dorsal 

 ray, in the type-species, divides dichotomously distally to form 4 

 small tips and is the only ray in relation with the small dorsal 

 lobe of the bursa. There are 2 voluminous sessile papillae, contigu- 

 ous or almost so, on the posterior lip of the cloaca. A pair of briefly 

 pedunculated prebursal papillae present. Spicules equal and short, 

 each dividing distally, in the type-species, to form 1 dorsal and 2 

 latero-ventral branches. No telamon (or gorgeret) present. Female 

 with vulva posterior to middle of body. Branches of ovejector 

 divergent or parallel. Uteri opposed. Eggs segmenting when 

 deposited. Parasitic in corneus tunic of gizzard in palmipeds. 



Type species. — Epomidiostomum. iineinatwm (Lundahl, 1848) 

 Seurat, 1918 (=E. anatinum Skrjabin, 1916). 



KEY TO SPECIES OF EPOMIDIOSTOMUM 



1. Males 6.03 to 7.13 mm. long; females 10 to 11.5 mm. long. Spicules 120 to 



130^ long Epomidiostomum uncinatum, p. 27. 



Males 8.8 mm., or more, in length ; females 13 mm., or more, in length. 

 Spicules 180 to 210/* long 2. 



2. Spicules dividing distally into 2 branches. 



Epomidiostomum querquetulae (Addenda, p. 3S4). 

 Spicules dividing distally into 3 branches 3. 



3. Head, in addition to lateral festoons, has 8 processes (4 lateral papillae and 



4 (2 dorsal, 2 ventral) posteriorly directed hooklike structures). 



Epomidiostomum orispinum, p. 28. 

 Head, in addition to lateral festoons, has total of 12 sharply pointed processes 

 (4 anteriorly directed at mouth opening; external to these, 4 horizontally 

 directed; and posterior to these, 4 (2 dorsal, 2 ventral) anteriorly di- 

 rected) Epomidiostomum skrjabini (Addenda, p. 3S4). 



EPOMIDIOSTOMUM UNCINATUM (Lundahl, 1848) Seurat, 1918e 



Synonyms. — Strongylus uncinatus Lundahl, 1848; Epomidiosto- 

 mum anatinum Skrjabin, 1916. 



Hosts. — Anas acuta, A. nigra, A. penelope, A. boschas domestica, 

 Anser albifrons, Fuligula nigra, Mareca penelope. 



Location. — Under the cuticular layer of the gizzard. 



Morphology. — Epomidiostomum (p. 26) : Slender worms, with 

 very narrow head ends. No buccal capsule; mouth with papillae 

 (lips?) directed outward. Cuticle of head end (fig. 24) with 2 

 epaulette-like ornaments, each terminating posteriorly in a free 

 border with 3 tooth-like structures. 



Male 6.3 to 7.13 mm. long by 15G> wide, yellowish. Cuticle trans- 

 versely striated. Esophagus cylindrical, 800/t long. Bursa (fig. 25) 

 with 2 large lateral lobes and a small dorsal lobe. Ventral rays 

 divergent; externo-lateral ray divergent from the latero-ventral ray 



