Thelastoma Leidy, 1849

Shah, Manjur, 2011, Nematode parasites of invertebrates from Manipur, North East India (Diagnosis, keys and illustration), Zootaxa 3107, pp. 1-37 : 13

Genus Thelastoma Leidy, 1849

Generic diagnosis. Female: Cephalic extremity formed by circumoral annule and enlarged second annule. Mouth surrounded by eight labial papillae. Amphids present. Lateral alae present or absent. Buccal cavity simple. Oesophagus consisting of an anterior cylindrical corpus, an isthmus and a posterior valvular bulb. Excretory pore pre- or post-oesophageal bulb or at the level of the base of the bulb. Tail long filiform, about one-third to one-fourth of the total body-length. Vagina short, muscular and anteriorly directed with well developed vulval lip. Vulva at or posterior to mid-body. Eggs broadly oval.

Male: Cephalic extremity formed by single expanded annule. Lateral alae present or absent. Tail elongated and filiform. Four pairs of caudal papillae, consisting one pair pre- anal, one pair adanal and one median duplex postanal papillae on genital cone. One pair of papillae on caudal appendage some distance away from the anus. Testis single. Spicule present or absent.