2 1 6 Studies in the Theory of Descent. 



colour is brown, although Boisduval 24 also figures a 

 1 'glit-green specimen; from which it may be inferred, 

 from analogy with Galii and Vespertilio, that the 

 first stages are green. In Dr. Staudinger's col- 

 lection there is a young larva, probably in the 

 fourth stage, the ground-colour of which is light 

 ash-grey. The dorsal and subdorsal lines are 

 white, the latter showing in the positions where 

 the ring-spots subsequently appear, small white 

 " mirrors " with red nuclei, exactly correspond- 

 ing to the stage of Vespertilio represented in 

 Fig. 49 A, PL VI. The "mirrors" are nothing 

 more than dilatations of the subdorsal line, which 

 is not therefore interrupted by them. The black 

 " ground-area " does not surround the " mirrors " 

 completely, but borders them only above and 

 below, and is much more strongly developed 

 above, extending in this direction to the dorsal 

 line. 



The fourth group comprises the two species 

 D. Lineata, Fabr., and D. Zygophylli, Ochs., the 

 former being the North American representative 

 of our D. Livornica, but differing in remaining 

 permanently at the fourth stage of this last species. 

 I am acquainted with D. Lineata only through 

 the figure of the adult larva given by Abbot and 

 Smith, which figure, judging from the position and 

 form of the spots, I am compelled to believe is 

 not quite correct, notwithstanding the excellence 

 24 Fig. 62, PI. VII. , is copied from Boisduval. 



