vi BUTTERFLIES 341 



It may be inferred from these definitions that the distinc- 

 tion between the two sub-Orders is neither sharply defined nor of 

 great importance. The club of the antenna of the Rhopalocera 

 exhibits considerable variety in form (Fig. 176). 1 Butterflies 

 are as a rule diurnal in their activity and moths nocturnal ; but 

 in the tropics there are numerous Heterocera that are diurnal, 

 and many of these resemble butterflies not only in colour but 

 even in the shapes of their wings. 



Series I. Rhopalocera. Butterflies. 



Classification and Families of Butterflies. Although 

 considerable unanimity exists as to the natural groups of butter- 

 Hies, there is much diversity of opinion as to what divisions are 

 of equivalent value some treating as sub-families groups that 

 others call families and as to the way the families should be 

 combined. There is, however, a general agreement that the 

 Hesperiidae are the most distinct of the families, and E. Eeuter 

 considers them a distinct sub-Order with the name Grypocera. 2 



Four categories may be readily distinguished, as follows, 

 viz. : 



1. The majority of butterflies ; having the first pair of legs more or less strik- 



ingly different from the other pairs ; frequently very much smaller 

 and not used as legs ; when not very small, then differing according 

 to sex of the same species, being smaller in the male than in 

 the female ; the part most peculiar is the tarsus, which is modified 

 in various manners, but in the males of this great series is ahv.iy- 

 destitute of its natural form of a succession of simple joints five in 

 number. There is no pad on the front tibia. 



Fam. XTMPHALIDAE, ERYCINIDAE, LYCAENIDAE. 

 [The distinctions between these three families are found in the 

 amount and kind of the abortion of the front legs ; for 

 definition refer to the heading of each of the families.] 



2. The front legs are in general form like the other pairs ; their tibiae 



have no pads; the claws of all the feet are bifid, and there is an 

 empodium in connection with them. Fam. PIERIDAE. 



1 For an account of the antennae of butterflies, see Jordan, JVur. Zuol. v. 1898, 

 pp. 37-1-415. 



- Haase first proposed the name Netrocera (Dcutsche cut. Zcit. Lcj>. iv. 1891, 

 p. 1) for Hesperiidae, as a division distinct from all other butterflies ; Karsch 

 replaced the name in the following year by Grypocera, because Xctrocera is the 

 name of a sjenus. 



