104 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



as long as the maxillae, cylindrical in outline, broadly rounded at 

 the distal end and covered with setae which are longer along the 

 mesal margins. 



Callosamia promethea 



This form (Figs. 15, 18 and 22) has a strongly chitinized cly- 

 peus, with the invaginations for the anterior arms of the tentorium 

 (Fig. 18, at) very prominent, and located at its ventro-lateral 

 angles. The clypco-labral suture is distinct, the labrum (Fig. 18, 

 lb) slightly concave along its distal margin and its width much 

 greater than the length. Laterad of the labrum on each side are 

 functionless mandibles (Fig. 18, md), heavily chitinized along 

 their mesal and caudal margins, the mesal margin irregular, but not 

 distinctly toothed, the proximal articulation having been lost. 

 Caudad of the mandibles there is a pair of maxillae (Fig. 18, mx), 

 separated by a distance equal to the width of the labrum. The 

 proximal part of each maxilla is conical and bears a short but well 

 defined two-segmented maxillary palpus (Figs. 18 and 15, mp) 

 which is more heavily chitinized than the basal part of the maxilla. 

 The distal portion of the maxilla (Fig. 15, mx) is triangular In 

 outline and is directed cephalad, the margin chitinized and dis- 

 tinctly serrate. Caudad of the maxillae and slightly nearer the 

 median line are a pair of clavate labial palpi (Fig. 18, Ip), the 

 proximal part chitinized at their point of attachment, the distal 

 portion covered with setae, as long or longer than the appendage 

 itself. The mentum and submentum (Fig. 22, sm and m) are fused, 

 strongly chitinized, and bear tw^o short setae on each side of the 

 meson near the proximal margin. At the base of each maxilla is 

 located an invagination for the posterior arms of the tentorium. 



Samia cecropia 



This species (Figs. 16, 20 and 21) has the clypeus (Fig. 21, cl) 

 strongly chitinized especially along the margin adjacent to the la- 

 brum. The invaginations for the anterior arms of the tentorium 

 (Fig. 21, at) are very large, oval in outline, and located along the 

 lateral margin of the clypeus. The clypeo-labral suture is distinct 



