New Species of Nygolaimoidea, Nygellus shamimi Sp. Nov. (Nematoda:Dorylaimida) with a first Record of Aetholaimus indicus from West Bengal, India

Thorne (1939) established the genus Nygellus with a single species clavatus having a combination of features of both Nygolaimidae and Belondiridae. Inspite of the nygolaimoid pharynx and mural tooth, he placed the genus under Belondiridae due to the presence of sheath of spiral muscles surrounding the basal expanded part of pharynx. Later Williams (1958) and Jairajpuri (1964) included two didelphic species Nygellus symmetricus and N. caudatus respectively in the genus because of the presence of spiral muscles around the basal part of pharynx. Clark (1961) transferred the genus Nygellus Thorne, 1939 to Nygolaimidae considering the nygolaimoid characters to be more fundamental and important than belondiroid characters.