340 LÉPIDOPTÉROLOGIE COMPARÉE 



Phylogeiiy. 



The phylogeny of the gênera in the group is not so clear as 

 would appear, but the following looks to be the most logical 

 séquence. It seems to me, that Bision stratana, so often used as 

 the type of the family, is so far removed from it, as to be in some 

 respects the last remnant of the forms Connecting the Lycïads 

 with the Ennondds through the genus Gonodontis. The ancestral 

 form, tlierefore, of thèse various gênera was some species of which 

 Lycïa hirlana and L. iirsaria are the existing représentatives. 

 Very early, the genus PhigaLïa branched off only to yield in turn, 

 firstly, the genus Microbiston, and secondly, Apocheima hispi- 

 daria. y\fter a period of development the forms included in the 

 genus Ithysia were evolved. This genus, of which /. alpina is, in 

 ail probability, the oldest form, tends to break into the two gênera, 

 Ithysia vera, containing the species zonaria and alpina, and the 

 subgenus Melanocoma, comprising the species, M. grœcaria and 

 M. italica. Perhaps the most highly specialised of thèse four 

 species is /. zonaria. The Lycia main stem now continued to 

 develop along lines of its own, finally to yield us the branch 

 Pœcilopsis, and in this, we hâve the species pomonaria, which 

 seems to be stable, and rachelœ and lapponaria, which are more 

 or less in a state of flux. 



No attempt is made above, to account for the origin of various 

 other gênera, such as BoarTnia, Hybernia, etc., ail more or less 

 allied to the species now being discussed. Some of them approach 

 very closely to the Lycia group at varying points in their life 

 historiés. 



Biology of the species. 



The biological characters of the species are much the same 

 throughout the whole of the gênera. The moths appear very early 

 in the year. Again the four species A. hispidaria, P. pedaria, 

 B. si rai aria, A. betularia are seen to be aberrant ; hispidaria, 



