1869.] 



189 



During the development of the butterflies the wing-covers became 

 at first whitish, and not transparent, and the eyes dark. On the third 

 day before the last the thorax became of a brown colour, the wing- 

 cases and the abdomen pale dirty yellow. Over the brown eyes the 

 the darker curved streak was still visible. The leg and wing-cases 

 had each received a broad longitudinal line, and the tips of the an- 

 tennaa showed themselves as two brown, elongated, longly-elliptical, ^ 

 small spots, between the ends of the wing-cases. On the day before 

 the last the wings and the end of the abdomen had taken a brown 

 colour.* The first butterfly (a female) appeared on the 31st May. 

 According to the time of extrusion of these four specimens, the 

 duration of the pupal state of the first generation (if there be a 

 second) is 12 — 14 days. The butterflies (2^,2 $ ) were true Arta- 

 xerxes. Only, one of the males had on the upper-side of the fore-wing, 

 instead of the white spot, nothing but a very small whitish dot, scarcely 

 perceptible, but, like the others, no trace of the black mark always 

 present in Ifedon. 



If I now compare the descriptions of the larvse of Medon and 

 ArtaxerxeSj made after a number of specimens, the difference in the 

 colour of the dorsal stripe is first noticeable ; purple-brown in Medon, 

 dark green in Artaxerxes ; and in the latter it is even differently formed, 

 — at least, I find in my memoranda about Medon nothing mentioned 

 about a narrowing of the same in the segments. 



But this being a difference of colouring, I lay no stress upon 

 it, any more than upon the colour of the lateral swelling, which in 

 Medon is simply purplish-red throughout, instead of being lighter in 

 the middle, as in Artaxerxes. The difference in the build, and in the 

 pubescence of the swellings, is much more important. It is said of 

 Medon, that those (swellings) situated near the dorsal stripe bear 

 numerous bristles of unequal length ; of Artaxerxes, that they have 

 only apparently thicker bristles than the rest of the body. I am sorry 

 that, relying upon the exactness of my last year's description of Medon 

 larvae, I have not drawn up that of Artaxerxes, with my notes upon 

 the former before me, and that, therefore, to make quite sure, new 

 descriptions will have to be taken. 



I therefore omit to point out also the other small differences, 

 which perhaps lie more in the words than in the reality. But supposing 

 that both larvae are built quite alike, and that the colour of the dorsal 



* The larva and pupa of Artaxerxes were described by Mr. Buckler in our last number (p. 176) ia 

 his usual careful manner, but we insert Prof. Zeller's description for the sake of comparison ; it will be 

 observed that the two agree in all Imoortant points, the diflferences being more those of words than of 

 reality.— Eds. 



