192 STRONGYLOIDEA 



Hab. Stomach, diaphragm and lungs of Cat. Larvae also 

 in Mice (one species known). 



Genotjrpe : O. tricuspis Leuckart, 1865. 



Leuckart, 1865, Arch. f. Naturg., xiii, 227; Cameron, 1923, 

 Journ. Helminthol., i, 157. 



Fam. 6. AMIDOSTOMIDAE nov. 



Buccal capsule very shallow but broad, without teeth, 

 cutting-plates or leaf-crowns at its anterior margin. Oesoph- 

 agus typically with tlu-ee axial chitinoid plates internally. 

 Spicules relatively short, bifurcate or trifurcate distally. 

 Vulva in posterior half of body. 



The members of this group possess some of the characters 

 of the Strongylidae and some of those of the Trichostrongy- 

 lidae. They cannot conveniently be assigned a definite 

 position in either of these families, and accordingly, small 

 though the group is, we feel compelled to accord it family 

 rank. 



1. Amidostomum Railliet & Hemy, 1909. 



Buccal capsule very wide, thick-walled, with one or three 

 teeth at its base. Oesophagus, with three axial chitinoid 

 plates extending throughout its whole length or reaching 

 to the posterior swelling. Bursa with long lateral lobes and 

 a short dorsal lobe. Externo-dorsal rays arise separately 

 from the dorsal ray and are short. Dorsal ray cleft for a 

 short distance only, and with bidigitate terminations. Pre- 

 bursal papillae present. Spicules equal, each divided for the 

 greater part of its length into two branches. An accessory 

 piece present. Tail of female long and finger-shaped. Uterine 

 branches opposed. ' 



Hab. Wall of gizzard of Ducks and other Birds. 

 Genotjrpe : A. [Strongylus} nodulosum (Rudolphi, 1803) 

 (= S. anseris Zeder, 1800, e.p.). 



Zeder, 1800, Naturg. der Eingeioeidewiirmer, 73 ; Rudolphi, 

 1803, Arch. f. Zool. u. Zoot., Brunswick, iii, 18; 1809, Enio- 

 zooruni Hist, not., ii, 230 ; Railliet & Henry, 1909, Compt. 

 rend.-Soc. Biol., Paris, Ixvi, 171; SlvTJabin, 1915, Mess. med. 

 vet. Soc. Petrograd, xxix, 694; Seurat, 1918, Bull. Mus. Hist. 

 7iat., Paris, 348. 



2. Epomidiostoraum Skrjabin, 1916. 



Cuticle thick, with conspicuous transverse striations. 

 Head distinct, with a pair of backwardly-directed " nodules " 

 or epaulettes dorsally and ventrally, hooked or blunt at their 

 tips. Buccal cavity short. Oesophagus with three internal 

 chitinoid lamellae. Tail of male hooked ventrally. Antero- 



