TKICHOSTRONGYLINAE 185 



Hab. Stomach of Ruminants, doubtfully of Mouse and 

 accidentally of Man. 



Genotype : //. [Strongylus] contorlus (Rudolphi, 1803). 



Rudolphi, 1803, Arch. f. Zool. it. Zoot., Brunswick, iii, 15; 

 Cobb, 1898, Agric. Oaz. N.8.W., Sydney, ix, 447; Ransom, 

 1911, U.S. Dejit. Agric, Bur. Anim. Indust. Bull. 127, 49. 



14. Nematodirus Ransom, 1907. 



Syn. ? Microcephalus Romanovitch, 1915. 



Body markedly tapering and thread-like anteriorly. An- 

 terior end with a slight vesicular swelling. Body with 

 eighteen longitudinal lines. Cervical papillae absent. Dorsal 

 lobe of bursa reduced to two small, short lobules, each sup- 

 ported by a separate ray. Ventral rays close together and 

 parallel. Postero-lateral ray divergent distally from the 

 other lateral rays. There is no unpaired median dorsal ray. 

 Spicules slender, relatively long, united by a membrane, at 

 least distally. Accessory piece absent. Tail of female 

 truncate, usually with a terminal spike. Vulva typically in 

 posterior region of body. Eggs relatively large (generally 

 over 150 [i, long). 



Hab. Stomach and small intestine of Mammals, chiefly 

 Herbivores. 



Genotype : N. [Ascaris] filicollis (Rudolphi, 1802). 



Rudolphi, 1802, Arch. f. Zool. u. Zoot., Brunswick, ii, 23 ; 

 Ransom, 1907, U.S. Dept. Agric, Bur. Anim. Indust. Circular 

 116, 4; Railliet & Henry, 1912, Bull. Soc Path, exot., Paris, 

 V, 36; May, 1920, Proc U.S. Nat. Mus., Iviii, 577. 



We have included as a doubtful s3rnonym of Nematodirus 

 the genus Microcej)halus Romanovitch, 1915 {Compt. rend. 

 Soc. Biol., Paris, Ixxviii, 451). This genus is insufficiently 

 characterized. The only character at present available to 

 distinguish it from Nematodirus is the position of the vulva, 

 which is stated by the author to be at the junction of the 

 anterior and second fourths of the body. It is significant 

 that M. longissime spiculatus Romanovitch shares with 

 Nematodirus the character, unique amongst the Tricho- 

 strongylidae, of having eggs over 150 (a in length (in 

 Romanovitch's species they are said to be 240 [x long). 



15. Mecistocirrus Railliet & Hemy, 1912. 



Body markedly attenuated anteriorly. Anterior end with 

 a slight vesicular swelling. Cuticle of body with numerous 

 inconspicuous longitudinal ridges. Cervical papillae con- 

 spicuous, spine-like. Mouth subterminal, slightly dorsal, 

 with a large buccal lancet. Bursa divided into two lateral 

 lobes and a small, but distinct, dorsal lobe. Ventro-ventral 



