8 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



angular with apex forward of the median incision of the labrum. 

 Labrum (pi. 2, fig. 2) rather narrow, with two setse-bearing 

 tubercles; median incision deep and strongly chitinized on the 

 edges; between these and extending outwardly a small oval 

 epipharyngeal shield (es) visible only under oil immersion; distal 

 edge of median incision serrate. Mandible (pi. 2, fig. 1) flat; 

 three-toothed; distal fourth of median edge projecting and den- 

 tate. Labium (pi. 2, fig. 3) thrust well forward, spoon-like with 

 distal margin serrate and anterior concavity rounded; no labial 

 palpi; under oil immersion a well defined stipes; labium extend- 

 ing far back into head, with no apparent articulation between 

 mentum and sub-mentum. Salivary ducts plainly visible and 

 joining to the front to form what appears to be a very rudi- 

 mentary spinneret, seen only under oil immersion. Hypopharynx 

 finely haired on forward portion only. Maxilla? with palpus 

 absent; origin of lacinia in palpiger not defined; lacinia bearing 

 two bristle-like digiti; no distinct joint between palpiger and 

 stipes, the latter considerably elongated; cardo small and tri- 

 angular. Triangular plates of hypostoma (pi. 3, fig. 1) small 

 and separated by slightly less than |. On the ventral side of the 

 head-capsule approximate to each antennal ring is a pair of hair- 

 less tubercles. Otherwise the head-capsule is smooth. Length 

 of larva before first moult 0.75 mm. ; before second moult 1.25 mm. 



After the larva has moulted for the second time it bores into one 

 of the branching ribs which it mines during the whole or greater 

 part of the third instar. The later instars, two of which we are 

 able to account for, are passed in the mid-rib within which the 

 larva mines (pi. 1, fig. 5) up or down, as the case may be, and 

 from which it emerges when ready to spin its cocoon. As a rule 

 the path of the mine is upward, the larva emerging from the 

 upper side of the rib near the tip (pi. 1, fig. 2). In some cases 

 where the leaf is too small for the mid-rib to afford sufficient 

 nourishment, the larva continues to mine from there into the 

 fleshy part of the leaf making a large irregular blotch (pi. 1, 

 fig. i) quite similar to that of Mnemonica. This habit however 

 is quite abnormal. 



The first two instars are the only ones in which the larva? are 

 of the flat gracilariid type. 1 The third instar larva is transitional 

 between these and the typical cylindrical gracilariid form of the 

 following instars, but with pronounced affinities to the latter. 

 It is cylindrical, has well developed spinneret, labial and maxil- 

 lary palpi and appreciable body seta?. There are, however, no 

 noticeable legs or abdominal feet and the head-capsule while 



1 During these stages they are what Tragardh designates as sap-feeders. 

 Comp. Tragardh: Archiv. for Zoologi., Band 8, No. 9, 1913. 



