Geographical Distribution.— West Africa, especially in Congo.
Genus. Acanthocheilonema, Cobbold, 1870.
Cuticle striated longitudinally. Œsophagus divided into two portions. Tail in both sexes with short lateral conical cuticular appendages. Spicules unequal, the larger membranous distally, the smaller hooked. Vulva in œsophageal region.
Acanthocheilonema perstans, Manson, 1891.
Syn.: Filaria perstans, P. Manson, 1891; Filaria sanguinis hominis var. minor, Manson, 1891.
The adult female Ac. perstans measures 70 to 80 mm. in length by 120 µ to 140 µ in breadth. The head is club-shaped and measures 0·07 mm. in diameter. The vulva opens at 0·6 to 1·0 mm. from the head. The tail is curved and presents a cuticular thickening which forms two triangular appendages. The anus opens at the apex of a papilla situated in the concavity of the curve formed by the tail 150 µ from the end. The diameter of the tail just before termination is 0·02 mm.
Fig. 298.—Acanthocheilonema perstans. 1, tail of male; 2, tail showing cuticular flaps devoid of fleshy contents. (After Leiper.)