1898] THE NEURATION OF RHOPALOCERA 393 
the next in sequence among the Pierids, viz. Huchloe, in which 
incorporation of one of the median nervules with the radial system 
of the forewings forms (as in Hesperids) a six-branched radius. 
WS 
Euchloe Leucophasia 
cardamines sinapts. 
(Pierids.) 
Pieris daplidice. 
Further specialization among Pierids is by reduction in the number 
of radial nervules in the forewings, and the movement of the remain- 
ing median nervule towards the radial system. The transverse 
‘cell’ nervure is a permanent feature throughout the Pierid group. 
Group 3.—Papilionids, The forewings have 
five-branched radial system, four-branched cubitus, 
only one median nervule remaining as such, a 
transverse cubitus and connection near the base of 
the wings, and two anal nervures. The hindwings 
have a subcostal-radius connection, a very per- 
sistent feature, which varies only so far as to 
form larger or smaller ‘ cells’ in different genera. 
One anal nervure only is typical of Papilionid 
neuration. All other groups (7.e. Groups 1 and 
2) have two anal nervures in the hindwings. 
From these notes it will be seen that however 
widely the specialized Rhopalocera may differ, u 
the generalized forms of neuration have features Papilio machaon 
in common—five-branched radius, two median (Eepiionia): 
nervules as such, three-branched cubitus in forewings (Groups 1 and 
2). Dr Grote believes it is “ uncertain” that the short anal nervure 
of Papilionid forewings, is homologous with the rudimentary anal 
nervure in the forewings of other groups, and conceives a separate 
origin for Papilionids. In such groups of Heterocera as have two anal 
nervures in the forewings, a rudimentary nervure is often present (see 
Cossids), always at the base of that anal nervure farthest from the 
cubital system. Comstock figures Megalopyge crispata, a ‘low’ 
moth which has an extension of the rudimentary nervure, a remnant 
of a third anal nervure in the forewings. Most Rhopalocera have lost 
one anal nervure (nearest the cubital system), a loss observed in many 
Heterocera; Papilionids retain two, one of which has become rudi- 
mentary in other groups of Rhopalocera (also in Cossids and many 
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