GENERAL INTRODUCTION. 23 



The meral half of the sternite is made up of the paramerum 

 (pam) and the protomerum (prm), two more or less strongly 

 convex plates, together with the large epimerum (em). 

 A marginal strip {m,p), situated along the meral cavity, is 

 separated by a more or less distinct suture from the epimerum. 



The meta sternite is more simplified than the mesosternite. 

 The episternum and epimerum are the only large plates. 



Leg (fig. 6 C, D, E, F). — The segments forming the leg 

 comprise the coxa, trochanter, femur, tibia and tarsus. 



The coxa is inserted in a groove formed by the sternal 

 part of the sternite. The trochanter (troch) is borne by the 

 coxa and is supported behind by the merum. The femora 

 always remain simple. Tibia and tarsus undergo several 

 modifications. The apex of the fore tibia is often produced 

 into a strong process (a thorn). The tibiae are more or less 

 spinose. The mid-tibia has one pair of slender spurs. The 

 hind tibia possesses normally two pairs of spurs, but the 

 proximal pair very often disappears. 



The mid-tarsal spines are specialized to form a comb in 

 many Sphingid^e, especially in Acherontiin^. The hind 

 tarsus is generally longer than the mid- tarsus. The comb is 

 less strongly developed. 



The fifth segment of all tarsi bears some stout and pale 

 sensory hairs at the end on each side close to the apical spine, 

 forming often a brush. There are two long bristles dorsally 

 close to the edge, curving ventrad. 



The claw-segment is composed of the claw (onychium), 

 the false claw (paronychium), the pad (pulvillus) and the 

 empodium. The empodium is a small tubercle above the 

 pad between the claws, bearing one bristle, seldom two. 

 It is seldom found in Sphingid^e. The claws are simple 

 and dilated at the base. The pulvillus (pulv) is sometimes 

 absent. The paroncychium (par) possesses in its most 

 generalized state two slender lobes on each side. 



Wings (fig. 8). — The neuration or arrangement of the veins 

 of the wing is dealt with in the systematic section. The 

 frenulum and retinaculum are sometimes reduced, vestigial 



protomerum ; psc, prcescutum of mesothorax ; st, sternum ; 

 smn, meral suture ; sti, stigma ; tckin, trochantinus ; troch, 

 trochanter. 



B. Mesothorax of Herse convolvuli, frontal aspect, aa, anterior wing ; 



endow, endoskeleton ; sc, scutum ; other lettering as in A. 



C. Mid-tibia of Nephele accerdifera, showing spurs and base of first 



tarsal segment. 



D. Tarsus of Acherontia styx ; first and second protarsal segments, 



lateral aspect. 



E. Tarsus of Cocytius duponchel ; fifth and claw-segment of fore tarsus, 



lateral aspect, par, paronychium ; mdv, pulvillus. 



F. As fig. E, ventral aspect. 



