Alexander, C.P. 1915. On a collection of Javanese crane-flies (Tipulidae, Diptera) in the United States national museum. Proceedings of the United States National Museum 49: 169.
Three subgenera of Helius are known from the Oriental Region (Eurhamphidia, Helius, and Rhampholimnobia). They are grouped based on the possession of a rostrom whoes length is greater that that of the remaining head and may exceed nearly 5 times its length. The elongate rostrum seen in Helius is similar to that of both Elephantomyia and Toxorhina, but is separated from the former by a lack of tibial spurs and by the singular setae of the legs from the latter (bifid in Toxorhina).
Helius (Rhampholimnobia) is similar to H. (Eurhamphidia) by in placement of crossvein R-M before the split of R4 and R5 but is separated by its thicker and more strongly produced rostrum and 15 antenal articles (16 articles in H. (Eurhamphidia) and H. (Helius)). Helius (Rhampolimnobia) is separated from H. (Helius) by the placement of R-M before the split of Rs, its placement after the split of Rs in H. (Helius).
Head: Anterior vertex suppressed, present as a thin strip. Rostrum thick and strongly produced, much longer than head, about equal to length of head and thorax combined. Maxillary palps length less than or subequal to head without the rostrum; basal palpomeres subequal, ultimate palpomere may be longer than preceding segments. Antennae: 15-16 articles; antennomeres variable.
Wings: Subhylane, commonly patterned with clouds of brown located along veins; cells without microtrichia; wing base not narrowed at wing base, anal angle of wing present. Wing venation: Sc short, Sc2 not removed from Sc1, both elements ending between origin and split of Rs; R1+2 straight to wing margin; R2 absent; Two branches of Rs (R4, R5) attaining wing margin; R-M crossvein about its length before split of Rs; two Medial veins (M1+2, M3) attaining wing margin; cell dm present; two Cubital veins (CuA1, CuA2) attaining wing margin; two Anal veins (A1, A2) attaining wing margin.
Male hypopygium: 9th tergite (9t) and sternite (9s) fused to a continuous ring. Mesoventral lobe of gonocoxite absent or weakly present. Gonostylus divided; dorsal gonostyle a simple sclerotized rod; ventral gonostyle bulbous based with a narrowed slender apex. Aedeagus variable, with one or two terminal openings. Proctriger simple, without modification.
Helius (Rhampholimnobia) is known only from the Oriental and Australian/Oceanic Regions. The Oriental Region has a weak representation of the subgenus and contains 2 of the 16 known species, 1 from the Philippines and 1 widespread throughout Indonesia and the Phillippines.
The larval habitats of H. (Rhampholimnobia) have not been determined for any of its species. It is expected that the preferences of this subgenus would be similar to that of H. (Helius), which are known to inhabit detritus in wet woodlands, marshes, or splash zones.
