Yin 



IBTTEODUCTICXN'. 



Fig. 4. 



Fig. 4. — Antenna (apical portions' much enlarged), a. Dccnais ; b. Orso- 

 trioena ; c. Hypolimnas ; d. Pareba ; e^Lihythea ; f. Abisara ; g. Papilio ; 

 ^. P?cm ; y. Lampides ; &. Tagiades. 



For classificatory purposes the roost important parts are : — J 



#«fltf (Fig. 2, I. & II.).— The labial palpi, b, b. These, in all 

 butterflies, are three-jointed and variable in shape and in the 

 clothing of scales or hair, but constant in each genus. They are 

 independently moveable, but their function, if they have any, is 

 unknown. The antennee (e, e & II., also fig. 4) are evidently organs 

 of perception. They are composed of an indefinite number of 

 joints, and vary greatly in length and thickness, in the shape of 

 the club, in the amount of scaling, and in the arrangement of the 

 sensory hairs and pits. In very many forms they are grooved on 

 the underside *. 



Thorax. — The appendages, the wings (figs. 5-10) and the legs 

 (fig. 11), are of the utmost importance in classification. 



Wings. These are membranous, traversed from the base out- 

 wards by nervures (" tubular structures which serve at once as 

 extensions of the tracheal system and to form a stiff framework 

 for the support of the wing"). In the vast majority of the 

 butterflies they are covered on both upper and under sides with 

 flat scales arranged in rows, and often brightly coloured. The 

 usual number of nervures in the wings of butterflies are : fore 

 wing 12 ; hind wing 9, beside the subcostal, median, and disco- 

 cellular veins ; but one or more of these may be absent, or there 

 may be one or two extra veins or portions of veins developed. 



Special note should be taken of fig. 5, as the details given 

 explain the terminology used in the descriptions of the forms 

 throughout this work. This terminology is different from that 

 used in Moore's and de Niceville's works. The following few 

 additional terms will also be met with : — Anterior or upper and 



* A most important paper on the antennse of butterflies has been published 

 by Dr. Karl Jordan in 'Novitates Zoologicse,' v, 1898, p. 374. 



