50 FOSSIL, BUTTERFLIES. 



den beiden Mitteladern gcschlossen 1st odcr nicht, war mir nicht moglich zu ermit- 

 teln; bei guter Belcuchtung glaubtc ich dort einen schwaehen Querandruck zu se- 

 hen, der als Yerbindungsast zu dcutcii ware ; jcdenfalls ware derselbe aber ausserst 

 zart, viel zarter als die iibrigen deutlicben Adern. Die aussere Mittelader sendet 4 

 Aeste aus, der erste entspringt nahe der Fliigelbasis und lauft nach dem Aussen- 

 rande, die drei folgcnden entspringen nahcr fliigelspitzwarts. Die v. interno-media 

 zerspaltet sich in 3 Aeste, ganz so wie die des Oberflugels, welche auch in gleicher 

 "Weise verlaufen. Alle 3 Aeste sind fast gleich weit von einander entfornt und 

 entspringen nicht von einem Punkt. Die vena analis zerspaltet sich bald nach 

 ihrem Ursprung in zwei Gabeliiste, welche nach aussen laufen. Die Farbe des 

 Fliigels ist ein helles Graubraun. 



As far as the neuration is concerned (excepting that of the costal nervure, 

 which is certainly incorrectly rendered, and does not accord with the description) 

 it agrees sufficiently with the general neuration of Mylothris 1 to suppose it may 

 belong to the allied genus Mylothrites, but that it can belong to M. Pluto is 



exceedingly improbable, as one may judge by tracing the 

 probable extent of the broken hind wing, and placing the 

 tracing in juxtaposition with the fore wing of Pluto, as in 

 the accompanying woodcut (fig. 1) ; for it must be remem- 

 bered that in all the genera of this subfamily, the cell 

 extends at least to the middle of the wing; the hind wing 

 of M. Pluto must, therefore, have certainly been fully one- 

 sixth longer than the wing conjectured to belong to it; 



Fig. 1. The dotted enter border of 



the hind wing represents the proba- so great a difference is at least unusual among indi- 



ble limit of the Gratz fossil. The 



broken outer border indicates the yiduals of the same species in this group ; moreover, the 



probable size of the hind wing of 



neuration is not quite what we should expect, although 



the appearance of veins on the drawing we have reproduced must be in part 

 due to extraneous causes; we will, therefore, make no attempt to decipher the 

 present condition of the fossil, trusting that some of the Austrian lepidopterists 

 will give the subject early attention. 



A study of the original description and illustration of the front wing of this 

 butterfly leads me to the conclusion that the description of the neuration of 



1 Compare the illustrations referred to in the note on page 4 1 . 



