

Phylctic Parallelism in Mctamorf>hic Sficcics. 433 



this account progress with that peculiar " looping " 

 movement which strikes even the uninitiated. 

 This group, which is very small, is however the 

 only one which can be founded on the morpho- 

 logy of the larvae ; it comprises only two nearly 

 related families (Phytomctrida and Dendrome- 

 trida), and it is not yet decided whether these 

 should not be united into one group comprising the 

 family characters of the whole of the " loopers." 



Neither the group of Micro-lepidoptera, nor 

 those of the Noctuina, Bombycina, Sphingina^ and 

 Rfwpalocera, can be based systematically on larval 

 characters. Several of these groups are indeed 

 but indistinctly defined, and even the imagines 

 present no common characteristics by which the 

 groups can be sharply distinguished. 



This is well shown by the Rliopaloccra or but- 

 terflies. These insects, in their large and gene- 

 rally brilliantly coloured wings, which are usually 

 held erect when at rest, and in their clubbed 

 antennae, possess characters which are nowhere else 

 found associated together, and which thus serve 

 to constitute them a sharply defined group. 3 The 

 caterpillars, however, show a quite different state 



1 [Lepidopterists are of course aware that even these distinc- 

 tions are not absolute, as no single character can be named 

 which does not also appear in certain moths. The definition 

 in this case, as in that of most other groups of animals and 

 plants, is only a general one. See, for instance, Westwood's 

 " Introduction to the Classification of Insects," vol. ii. pp. 

 330 332. Also some remarks by C. V. Riley in his " Eighth 



Ff 



