41 



This family is usually divided into subfamilies of which two, the 

 Cossinae and Zeuzerinae, are discussed here. Figure 15 shows the 

 ventral surface of the head and its appendages in a member of the 

 Cossinae, the arrangement of the other parts being the same as in 

 the Zeuzerinae (Fig. 16). 



The maxillae have prominent lateral projections in Cossinae which 

 resemble maxillary palpi. These always adhere to it at dehiscence 

 and are not found in Zeuzerinae. Only one genus of each subfamily 

 was studied. The pupae are very large, those of Prionoxystus robin- 

 iae and Zenzera pyrina being respectively 45-50 mm. and 30-35 mm. 

 in length. The two genera studied may be separated as follows : 



a. Head without a prominent cephalic projection; maxillae with an 

 apparently segmented lateral projection on each side resembling a 

 maxillary palpus, but adhering to the maxillae at dehiscence; an- 

 tennae more than half the length of the wings and gradually taper- 

 ing ; abdominal segments with the cephalic ridges much larger than 

 the caudal ones and armed with long even teeth. 



Prionoxystus Grote. 



aa. Head with a prominent cephalic projection, maxillae never with an 

 apparently segmented lateral projection 011 each side ; antennae less 

 than half the length of the wings and narrowed abruptly near the 

 middle ; abdominal segments with the cephalic and caudal ridges 

 similar, the teeth short and uneven Zeuzera Latreille. 



The following species were examined : 

 Prionoxystus robiniae Peck 

 Zeuzera pyrina Linnaeus 



Superfamily EUCLEOIDEA 



The pupae of this superfamily are quite specialized as to the head 

 parts, the epicranial suture being the only one visible in all the 

 families. They have followed a very different line of development 

 from the Cossoidea and Hepialoidea, because all of the generalized 

 families retain freedom of motion between all the segments except 

 those fixed at the caudal end of the abdomen, and between all of the 

 appendages. The cuticle is very thin and transparent in almost all 

 genera and the dorsum of the abdominal segments in all of them has 

 a covering of small spines over the greater part of the segment. All 

 of the families show the spiracles distinctly on the first abdominal 

 segment. The only other family in which this was observed, the 

 Nepticulidae, has a well-developed maxillary palpus. The meso- 

 thoracic spiracle of each side is in a rather unusual position in this 



