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: 168.
Three subgenera of Helius are known from the Oriental Region (Eurhamphidia, Helius, and Rhampholimnobia). They are grouped based on the possession of an elongate rostrum with length that is greater than that of the remaining head, and may exceed nearly 5 times the length of the head. 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 (Eurhamphidia) is separated from H. (Heilus) by placement of crossvein R-M before the split of R4 and R5 and from H. (Rhampholimnobia) by number of antennal segments (16 in H. (Eurhamphidia) and 15 in H. (Eurhamphidia)).
Head: Anterior vertex suppressed, as a thin strip between the eyes. Rostrum subequal to or slightly longer than head, not exceeding length of head and thorax combine. Maxillary palpus less than or subequal to head without the rostrum; basal palpomeres subequal, ultimate palpomere longer than preceding segments. Antennae: 16 articles; antenomeres variable suboval or cylindrical.
Wings: Subhylane, commonly patterned with clouds of brown located along veins; cells without microtrichia; anal angle of wing present. Wing venation: Sc short, Sc2 not removed from Sc1, both elements ending between origin and split of Rs; R1 straight to wing margin; R2 absent; two branches of Rs (R3+4, 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; distal wing chord in general alignment in distal 1/3 of wing; 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. Mesoventral lobe of gonocoxite weakly present, uncommonly reduced. Gonostylus divided; doral 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.
The species of H. (Eurhamphidia) are limited to the Oriental (14 species) and Australian/Oceanic (9 species) Regions.
The larval habitats of H. (Eurhamphidia) have not been determined for any 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.
