100 JOUENAL OF ENTOMOLOGY AND ZOOLOGY 



of the clypeus and labrum. Just proximad of the Hne indicating 

 the distal margin of the labrum is a more or less triangular, slightly 

 chitinized area. Laterad of this slightly chitinized area on each 

 side is a group of sensory pits (Fig. 5, sp). At the right is shown 

 the anterior arm of the tentorium (Fig. 5, at). The fulcrum is 

 seen as a narrow, chitinized T-shaped rod on each side fastened at 

 base to the anterior arm of the tentorium (Fig. 5, fu). Proximad 

 of the T-shaped fulcrum there is, on each side, a thinly chitinized 

 quadrangular area which narrows to a point mesad of the fulcrum. 

 The dotted lines at the proximal end indicate the proximal end of 

 the pharynx. The arrangement of these parts is very similar to 

 that found in such mandibulate insects as the cockroach and grass- 

 hopper. Laterad of the labrum (Fig. 3, md) at each proximo- 

 lateral angle between the clypeus and labrum is a thin, colorless 

 appendage, undoubtedly a mandible. The maxillas of Archips are 

 well developed, more than twice the length of the head, the two 

 parts lying closely approximated so that they can be fitted together 

 to form a tube. The distal half of each maxilla (Fig. 3, mx) has 

 a number of fine short setas along the lateral margin. Beneath the 

 maxillae may be seen the labial palpi (Fig. 3, Ip), which are slightly 

 wider than the maxills, about half their length and densely covered 

 with fine setae. In a \'entral view (Fig. 4) there may be seen, at- 

 tached to the lateral margin at the base of the maxilla, on the side 

 from which the labial palpus has been removed, a slender four- 

 segmented maxillary palpus (Fig. 4, mp). Each maxillary palpus 

 extends laterad towards the antenna, then is directed cephalad until 

 it reaches the ventral surface where it bends mesad and lies closely 

 appressed to the caudal margin of the eye and is seldom seen in 

 cephalic view. 



Hemerocampa leucostigma 



The next form considered was Hemerocampa leucostigma, a 

 liparid. In this form the adult mouth-parts are functionless, but 

 in the preimago the parts found in the previous forms were all pres- 

 ent, the mandibles (Fig. 12, md) being much more distinct and 

 mandible-like than in either Stlieiiopis or Archips and leaving no 

 doubt as to their identity. The clypeo-labral suture is obsolete and 



