GENERAL INTRODUCTION. 21 



The antennae, when strongly clubbed, have the proximal 

 segments occasionally nearly or totally scaled. The sense- 

 bristles are stiff hairs of varying length. The normal number 

 of the bristles found on the non- scaled surface, if we except 

 the end-segment, is two on each side. The number is some- 

 times doubled, but there is never a complete transverse 

 series, and the bristles are never apical. The dorso -lateral 

 bristles, situated close to the edge of the scaled area, are very 

 often so prolonged and become so stout that the antenna 

 has the appearance of being pectinated. 



There occur all intergradations in shape between the most 

 strongly clubbed antenna of Haamorrhagia to the setiform 

 antenna of Megacorma. The cilia are apparently always 

 fasciculate. They occur in the males of all Hawk-Moths, 

 except Rhopalopsyche, and are also present in a good many 

 females, though they are here always developed in a lesser 

 degree than in the respective males. 



The well-known hook in which ends the antenna of very 

 many Sphingidje, but not of all, occurs in all subfamilies. 

 The end-segment is of particular taxonomic value. The 

 length and shape, and the clothing with scales and bristles 

 of this segment, vary very much and offer good distinguishing- 

 characters of genera and even tribes. 



The eye is subglobular and varies much in size. It is 

 never hairy, but is often covered above by a kind of eyebrow 

 and below by a large tuft of hairs. 



Thorax (fig. 6 A, B). — The mesonotum, composed of the 

 prsescutum, scutum and postscutum (=scutellum), is very 

 large. The prsescutum (psc) is distinctly triangular in dorsal 

 view. The scutum (msc) is widest behind and a little longer 

 than broad. The postscutum (mscl) varies obviously in size 

 and shape. Similar parts compose the metanotum. The 

 scutum (mtsc) is divided into two halves widely separate. 

 The postscutum (mtscl) is always narrow. 



The ventral parts of the meso- and metathorax do not 

 differ much in size. The sternum (st) and peristernum (pest) 

 are not completely separated from one another. The 

 peristernum is large and remains broad at the obliquely 

 truncate upper end, w T here it leans against the parasternum 

 (past). This is a large plate extending obliquely dorsad 

 and mesiad from the meral suture (smn), separating the meral 

 and sternal parts of the sternite, to the membrane connecting 

 meso- and prothorax. Between this plate and the notum 

 the mesothoracic tegula (mtg) is inserted. Below the para- 

 sternum lies the episternum (est), with which are fused the 

 hyposternum (hyst) and the marginal strips along the coxal 

 cavity. The episternum is always obliquely truncate, with 

 the upper inner angle more or less pointed. 



