OF WASHINGTON, VOLUME XVII, 1913 9 



rounded inclines somewhat to the flattened wedge shape. The 

 tentorial bridge and the ocelli are as in the flat instars, the latter 

 however more strongly and evenly pigmented. The mandibles 

 in shape approach those of the last stage. 



The larva of the fourth instar does not differ essentially in 

 structure from that of the last. 



The mature larva (pi. 4, fig. 1) is in general body characters 

 typical of the family. It is whitish, or, when it has fed up in 

 the blotch mine, greenish, without color markings. The abdomi- 

 nal feet bear seven crochets in two curved rows all pointing 

 backward (pi. 4, fig. 3). Tubercles and seta3 of abdominal seg- 

 ment as figured (pi. 9, fig. 1); using Dyar's numbers, we would 

 say that I is lower than II with I, III and V nearly in a straight 

 line, IV absent or coalesced with V, VI absent; anal segment as 

 figured (pi. 9, fig. 2). The head-capsule (pi. 5, figs 1, 2) is 

 rounded, the dorsal side projecting over the ventral f ; greatest 

 width slightly lower than middle of head, well forward of tentorial 

 bridge. Diameter of occipital foramen at dorsal extremity of 

 hind margin f , at ventral extremity a trifle under \. Length of 

 frons slightly over \; the frontal ridges converging in curved 

 lines to a longitudinal ridge (f long) connecting them with the 

 hind margin, which projects \ into the head; adfrontal sclerites 

 conspicuous but folded under frontal ridges. Tentorial bridge 

 as in first instar; slightly less than f in length; upper attachment 

 of tentorial arms at middle of frontal ridges. Ocelli, five, in 

 two longitudinal rows; 1, 2, 3, dorso-laterally placed; 1 and 2 

 grouped approximate to antennal ring; 3 back jj 4 and 5 grouped 

 opposite of 3 on ventral side; all with well developed lenses; 

 pigmented area broad and continuous under all the ocelli. An- 

 tenna (pi. 4, fig. 5) distinctly three-jointed; second joint with 

 two papilte and two hairs, the longer hair not extending beyond 

 the extremity of the antenna; third joint as in G. syringella. 1 

 Post-labrum normal. Labrum (pi. 7, fig. 2) curving well down 

 to the sides over the upper edge of the mandibles; median inci- 

 sion concaved and moderately deep; four pair of setae, V and VI 

 absent; 2 sides very thin, the lateral edges strengthened by a 

 chitinous bar with six branches projecting inwardly for a short 

 distance and giving a somewhat scalloped appearance to the 

 margin. Epipharynx (pi. 7, fig. 1) densely tufted with hair- 

 like filaments; the paired epipharyngeal plates tooth-like; epi- 

 phaiyngeal shield, heart-shaped, strongly chitinized and pro- 

 jecting beyond the median incision of the labrum. Mandible 



1 Comp. Tragardh: 1. c., pp. 16-17. 



2 We have followed the system of numbering used by W. T. M. Forbes 

 (Ann. Ent. Soc. Am., vol. Ill, No. 2, p. 96, 1910). 



