T 



( 28 ) 



The table inserted above shows tlie gradual reduction of the organs mentioned 



in the table. It will be observed that the highest forms, or the most reduced in 



this case, become similar in structure in consequence of the loss or reduction of 



"organs, thougli tlie insects are of different origin. Such apparently convergent 



ilcvehipment is remarkably well illustrated by this tribe of Hawk Moths. 



The naked streak on the innerside of the -second segment of the palpus reminds 

 one of the palpus of Tlieretra and allies, as do amongst the Aclterontiicae the 

 palpi of Mryarornifi and Acherontia, though in other respects. 



The great number iif genera in the Old World, and the occurrence in tlie c? 

 of a friction-patch an<l a completely divided tenth tergite only in some Old-World 

 forms, together witli the fact that the Acherontiieae are represented in the New 

 World only by one species, and the third tribe Sjihingulkae not at all, show clearly 

 that the subfamily Aclierontiinae is of 01d-^Vorld origin. The same applies to 

 the allied subfamily AmbiiUcinae. 



Key to the genera : 



n. Third segment of palpus naked, pointed, 



prominent ...... b. 



Third segment of paljjus not naked . . c. 



h. Long terminal spur of hindtibia a little 

 longer than tibia ; clasper with 

 friction-patch {$) . ■ ■ .V. Xrinthopan. 

 Long terminal spnr of hindtibia shorter 

 than tibia ; clasper without friction- 

 patch XVII. Cocytbis. 



c. Pul villus present il. 



„ absent, or reduced to a short 

 triangular lobe . . . . . f. 



(I. Foretibia with spines ..... c. 

 „ simple j. 



e. Two pairs of spurs to hindtibia . . • /■ 



One pair „ „ ,, ,, . . XXXVI. Tkamnoecka. 



f. Paronychium with two lobes on each 



side ; ground-colour of hindwing 



yellov/ ...... VI. l'iino(icn(t. 



Parnnychinm with one lobe on each 

 side ; ground-colour of hindwing 

 not yellow g. 



g. Spurs densely spinose, long apical one 



of hindtibia half the length of the 



first tarsal segment . . XVI. Praedora. 



Spurs not spinose, long apical one of 

 hindtibia more than half the length 

 of the first tarsal segment . . . h. 

 It. D' of hindwing very oblique, twice the 



length of D^ ; Africa . . . XI. Pemba. 



\y of hindwing not very oblique, as long 



as or siiorter than D" : America . . /. 



