382 THE ENTOMOLOGIST. 



first stage has the " body pale green " ; this is certainly mis- 

 leading, as in no period of its first stage is any green visible. It 

 is pearly-grey, or cobweb colour, when first hatched, and remains 

 almost unchanged, excepting becoming even paler until after its 

 first moult. 



THE ATHALIA GROUP OF THE GENUS MELITMA. 

 By Rev. George Wheeler, M.A., F.E.S. 



(Concluded from p. 267.) 



There is one further point with regard to this group which 

 is of great interest, and to which my attention has been turned 

 throughout the time during which I have been studying it, viz. 

 its phylogeny, and I have delayed treating of the subject in the 

 hope of being able to come to some definite conclusion. The 

 whole question is, however, so complicated, and the evidence 

 available seems in some respects so contradictory, that I can do 

 little more than throw out suggestions which may possibly be 

 of use in the future, if only as a basis for criticism. 



The group consists of a number of ill-defined species, some 

 of which are widespread, some local, and it is equally possible 

 to argue that the latter are the most ancestral forms which have 

 in most places been superseded, or the most recently developed 

 which have not yet spread themselves widely ; other considera- 

 tions seem to show that both arguments are true, and that in 

 different cases the local restriction of species must be referred to 

 opposite causes. In this group, for instance, it is probable that 

 asteria and varia are ancestral, deione and perhaps dictynnoides 

 (geologically speaking) modern species. For, in a group like the 

 Melitseids, which are to be found at the extreme heights of lati- 

 tude and altitude, especially when the same statement is true of 

 the nearly related Brenthids (and most true of the most nearly 

 related forms), it seems probable that the ancestral forms of the 

 group were capable of resisting the cold of the last glacial epoch, 

 and have spread themselves downwards both in altitude and 

 latitude, the oldest forms being those capable of enduring the 

 greatest amount of cold, and the most recent those which are 

 found in the warmest localities inhabited by any members of 

 the group. There may, however, always remain an inherited 

 tendency towards the power of sui^porting cold, which would 

 enable forms of southern origin to spread northward, as deione 

 seems disposed to do, and lowland forms to mount upward, as 

 may possibly be the case with athalia and parthenie, and even 

 with dictynna. 



In a group consisting of well-defined species it would no 

 doubt be rash to suggest the direct descent of one existing species 



