( 15 ) 



RHOPALOCERA. 



Imago. — Head of moderate size (rather large in the family Hespe- 

 ridce). Antennce slender ; the joints of the middle third longer than 

 broad ; some of the terminal joints almost always broadened more or 

 less, so as to form a club ; bases of insertion close together (except in 

 the Hesperidm). Labial paljn well-developed, ascendent, three-jointed, 

 scaly, more or less hairy (except in many cases the terminal joint) ; 

 the middle joint almost always the longest. Haustellum always well- 

 developed (longest in the Hesperidce). Stcmmata obsolete. 



Thorax compact, rounded anteriorly and posteriorly, usually rather 

 thick and deep, with the sides somewhat flattened; mesothorax with 

 its dorsal median suture and posteriorly-situated triangular scutellum 

 usually very distinct. Wings large and broad, without the bristle and 

 socket (retinaculum) found in most Heterocera ; -^ general outline of 

 fore wings sub-triangular, of hind wings sub-circular ; neuration almost 

 wholly longitudinal, with the exception of the disco-cellular nervules, 

 and in its main plan the same in both fore and hind wings ; near 

 bases, especially in hind wings, usually a clothing of fine hairs as well 

 as of scales; fringe of hair-like scales (cilia) projecting from outer 

 edge (hind-margin) of wings usually short. Legs slender, rather short ; 

 the first pair often atrophied (family Nymphalidce, and males of family 

 Erycinidoi) ; femora generally hairy ; tilioi and tarsi finely spinulose ; 

 tihice of hind pair armed with a terminal pair of spurs only (except in 

 the LLcsperidoi, almost all of which have an additional pair rather 

 beyond the middle of the joint) ; tarsi terminating in a pair of simple 

 or bifid claws, usually accompanied by a foot-cushion (^idvillus) and 

 two bifid supplementary membranaceous claws (paroiiychia). 



Abdomen short (except in the Sub-Families Danaince,I[eliconince, and 

 Acrceina^), slender, laterally compressed, dorsally arched, and with more 

 or less of a median ridge ; the extremity inferiorly obliquely truncate, 

 and fissured longitudinally for the anal and genital outlets. 



Larva. — Usually elongate and sub-cylindrical (but widened and 

 inferiorly flattened — onisciform — in Family Lyccenidm and in some 



^ This structure, which links together the fore and hind wings in many Moths (and is 

 particularly well shown in the Sphinges), is formed by the free precostal nervure at the base 

 of the hind wing passing through a small horny loop or ring, which arches the subcostal 

 nervure near the base on the under side of the fore wing. 



