420 On (I neio TrichosironnyJfi Genus. 



together with the presence of two ovaries Scz. in the female, 

 place it in the subfamily Trichostrongylinte, Leiper, 1908. 

 This parasite differs widely from all known Trichostrongyle 

 genera, its closest relation possibly beintr Cooprria, R;uisom, 

 1907. It, however, differs from Cooperia in sevoral respects, 

 more especially in the shape of the dorsal ray and the relative 

 thicknesses of tiie lateral rays of the bursa. Tlie position of 

 the vulva in this parasite is also quite different, in being 

 placed much further back than in Cooperia. 



I propose to designate this parasite as type-species of a 

 new genus 



Trichohelix, gen. nov., 



of which the following may be taken as the chief characters : — 

 Trichostrongylinte. Body red and spirally coiled. Head 

 round and thick, about 35 ft in diameter. Cuticle round 

 liead inflated to form a vesicular swelling, limited behind 

 by a deep constriction encircling the neck. Rest of the 

 cuticle strikingly inflated and showing marked transverse 

 striations only on the anterior half of the ventral surface. 

 Longitudinal striations faint. Lateral alai absent. Cervical 

 papilla} absent. Male bursa indistinctly trilobate. Dorsal 

 ray stout, bifurcate, and its tips are tripartite. Tip of raedio- 

 lateral ray sharply recurved. Ventro-ventral ray strongly 

 arched forwards and inwards. Spicules straight, tubular, 

 equal, and of mediutB size ; they are branched posteriorly. 

 Gubernaculum present. Prebursal papilla; absent. Vulva 

 situated slightly in front of the anus. Ovijectors w^ell deve- 

 loped and divergent. Uteri parallel. Eggs large, oval, and 

 thin-shelled, measuring over 100 /x in length. 



Type-species, Trichohelix tuherculata, Par. & Stoss., 1901. 



References. 



Hall, M. C. 1916. " Nematode Parasites of the Orders Rodentia, 



Lagomorpha, and Hjracoidoa." Proc. U.S. Nat. Mus. vol. 1. 



no. 2131. "Washington. 

 Leipkr, R. T. ]908. "An Account of some Helminthes collected in 



Sudan." Third Report of the Wellcome Research Laboratories, 



pp. 189-191. Khartoum. 

 IjTNSTow, O. vox. 1878. Compendium der Helminthologie. Hannover. 



. 1889. Compendium der Helminthologie, Nachtrag. Hannover. 



Moi.iN, R. 1861. 11 sottordine degli Acrofalli. Venice. 



Pabona, C, and SxossiCU, M. 1901. " (Esop/iaf/ostomiun tuhtrcn- 



lutum, n. sp., parasita dei Dasypus." Roll. d. Mus. d. Zool. o 



Anat. Comp. d. R. Univ. d. (ieuova, no. 1 10. 

 Ransom, B. H, 1911. '-The Nematodes par:v<itic in the .Mim.'ntary 



Tract of Cattle, Slieep, and otlier Ruminants." U.S. Dep.of Agric, 



liureau of Auim. Iiid. Rull. 127. WasLington. 



