( 676 ) 



Therctra, llippotioii, etc., occurriug in the Nearctic and Neotropical Regions. There 

 is DO question of mistaking an American species for an Old World one (or the 

 reverse), if the palpi are examined. 



The development of the midtibial spurs is most ])eculiar in so far as the inner 

 spur is in many species obviouslj- shorter than the outer one, while normally the 

 outer spur is the shorter. This abnormal relation of length is due to the reduction 

 of the inner spur. Some species are very interesting in this respect, showing 

 individual and sometimes geographical variation in the length of the spurs (amadis, 

 neclius, etc.). 



The venation of the hindwing is not quite constant in the genus, the position 

 of the cross-veins and the central veins being affected by the obvious diiference 

 in the shape of wing observed in some more distantly related species (compare 

 for instance tasa, pistacina, depuiseti). SC" and R' are sometimes stalked 

 (ccratomioides, etc.). 



Key to the species : 



a. Liuesofforewing transverse, their posterior 



parts not close together in middle of 

 inner margin, never longitudinal ; pale 

 band of hindwing not separated into 



spots b. 



Lilies of forewiug oblique, more or less 

 converging towards apex of wing . 



b. Band of hindwing ochre-yellow . 

 Band of hindwing not ochre-yellow . 



c. Body and forewiug ferruginous or uniformly 



pale cinnamon-rufous .... 

 Body and forewing not so coloured . 



d. Forewing with more than one line, hind- 



wing with conspicuous creamy patch or 

 band 



Only one distinct line on forewiug ; hind- 

 wing without creamy patch . 

 ('. First discal line of forewing forming a 

 heavy band which is more or less straight, 

 gradually shading off distally, while 

 being rather sharjjly defined proximally . . f. 



First discal line thin, often indistinct . . y. 



J. Bright greyish green above, hindwing 



black with green band .... ()2o. X. ti/iidariis. 



Dirty greenish buff, band of hindwing this 



same colour ...... 62G. A', pistacina. 



g. Abdomen with an isolated black basi-lateral 



jiatch, wings without green . . . O'.Jt). X. rhodoccra. 



Abdomen without an isolated black basi- 

 lateral i)atcli . . . . . . h. 



h. Inner edge of forewing white except at 

 base ; fringe of hindwing even, without 

 sharjily marked dots . . . . . . i. 



