70 William T. M. Forbes 



Suborder FRENATJE 

 (Heterocera, in part) 



Aculeas present only in a few of the most primitive forms. Ocelli, 

 when present, close to the upper margin of the eye, placed directly 

 behind the antennas, but often absent. Antennas with sense-cones except 

 in a few primitive forms, the second segment, or pedicel, usually pro- 

 portionately small. Vertex separated by sutures in the lower forms; 

 in the higher ones with practically all the head-sutures obliterated. 

 Mouth parts never of the mandibulate type, when not rudimentary 

 with the lab rum three-lobed, the central lobe filling the gap between 

 the bases of the two maxillae, the lateral lobes forming the pilif ers. 

 Maxillae with basal structures reduced ; the lacinia absent, and the palpi 

 in the majority of forms reduced or absent. Labium usually rudimen- 

 tary or absent, except for its three-jointed palpi. Thorax with the 

 third segment smaller than in the Jugatas, often reduced dorsally to a 

 narrow strip, but always developed ventrally for the attachment of the 

 legs ; the two halves of the scutum usually widely separated. Abdomen 

 in primitive forms (Adelidas) with a horny, piercing ovipositor (fig. 

 50), which becomes lost in the higher types, though the two pairs of 

 strong tendons and muscles are preserved. In many of these higher 

 forms the ovipositor ends in two lobes. 



Fore wing with humeral vein rudimentary or absent; Sc always 

 simple; R x always simple, base of media and 1st A often lost, 2d A 

 always preserved, and usually apparently forked at the base, as a 

 result of the attachment to it of the tip of the upper fork of 3d A; 

 lower fork of 3d A usually lost; (sometimes the lower fork is free, 

 or 3d A wholly lost). Jugum never present, the inner-marginal cord 

 always running directly into the scutellum. (In the nonaculeate 

 forms, there is a small patch of minute spines on the inner margin 

 near the base, which may be a persisting remnant of the aculeas). 

 Hind wing with the radius much reduced, typically with only one 

 free branch (Rs, usually spoken of merely as R) ; Rs once forked in 

 the lower Elachistidas, and in our genus Tinagma, in which latter genus 

 the dorsal venation is much reduced; R x crossing over to Sc and fused 

 with it from its junction to the apex, except in a few Gracilariidas 

 with very narrow wings ; if Sc and Rs remain separate, 'R 1 looking 

 like a crossvein, usually located near the base of the wing in those 

 forms where Sc and R s remain independent, but often obliterated by 

 the fusion of Sc and R at the point where R x should cross. Hind wing 

 usually with three apparent anals, or two by the loss of 1st A; for 

 the upper fork of 3d A has become almost .completely fused with 

 2d A, in the Tortricidas and broad- winged Tineids (in the broad sense), 

 showing as a distinct basal fork of 2d A, as on the fore wing. Cross- 



