( S93 ) . 



Rhopalooera. Here the last one or two joints, at least, are not scaled as a rule: 

 but there are in all families (except P(ijiilionidae) instances of the dorsal surface 

 being entirely scaled, and it is especially worthy of note that this extended develop- 

 ment of the scaling is found in all Hesperiidne. The scaling of the ventral side is 

 ill the larger number of Butterflies restricted to the most proximal joints, a more or 

 less broad ventral stripe being bare of scales ; in the species with more extended 

 ventral scaling the proximal restriction is preserved in so far as the not-scaled 

 portion of the antenna is always (without exception) distal, the last joints being 

 ventrally never scaled. The not-scaled ventral area is extremely variable in extent 

 in the different forms of Butterflies. In all families, except llesperitdae, we find 

 the area restricted to the last joints or extending down the stalk, often to the base, 

 without regularity as regards a whole family. But within the families we find very 

 often groups of genera in which the extent of ventral scaling shows an obvious 

 constancy. The Papilwninae and most subfamilies of Ni/mphalidae have no 

 ventral scaling, while in Parnmsiinac, Ni/mphalinae, Sattjrinae, Acraeinae, as well 

 as in Pierinae, Erycinidae, and Lycaenidae, the ventral scaling is sometimes restricted 

 (or absent), sometimes extended to the club. A constantly very extended develop- 

 ment of the ventral scaling we observe in Hesperildae and TUsmorphiinae, ; in all 

 the species of these groups the not-scaled area is restricted to the club, never 

 extending down upon the joints of the stalk. Those Kymphalimu' and Satyrimie 

 which have the not-scaled area restricted to the last joints are generally small, weak- 

 bodied, species ; at least, if of two allied forms one is Hesperioid in the development 

 of the scaling and the other has the bare area extending down the stalk, the first is 

 the smaller one ; while, on the other hand, the species without antennal scaling are 

 generally stronger in body or larger than their near allies which have the antennae 

 scaled. 



In Heterocera ventral scaling is found in proportionally very few species, 

 occurring only in some of those forms which have clubbed antennae like Rhopalocera, 

 and in those Pyralidae and Tineidac which have very long and slender antennae. 

 In Castniidac the ventral side is either without scaling, or the not-scaled area is 

 restricted to the club and some of the distal joints of the stalk ; in Sesiidae the bare 

 area is similar in extent, but here the distal joints of the stalk and the proximal 

 ones of the club have a transverse series of scales at the apex, as is the case in 

 certain Lycaenidae {Ilypochrysops). In both those Heterocerous families the scaling 

 is in extent of a Rhopalocerous type, the bare area being distal. In the species of 

 Heterocera with very long antennae {Chimabacke, for instance) the distal portion 

 of the antenna is scaled all over, the not-scaled area being thus restricted to the 

 proximal half of the organ; in many cases this sense-hair-bearing portion of the 

 antenna is still more restricted, each joint having an apical transverse series of scales. 

 I have not found any species with filiform or setiform antennae (inclusive of pecti- 

 nated ones) in which the not-scaled area is distal, as in clubbed antennae. It is 

 evident that there must be some connection between the development of a club and 

 the restriction of the not-scaled surface to the distal joints. 



b. Pine Sense-Hairs.— The antennae bear two kinds of sense-organs, fine sense- 

 hairs and setiforous punctures, which are restricted to the not-scaled portion ; their 

 extent depends, therefore, to a certain degree upon the development of the scaling. 

 The fine sense-hairs are either found on the ventral surface only, or they occur 

 ventrally and dorsally. The latter type is very rare; we meet with it among 

 llepiaUdae, of which a number of species have all the ventral and dorsal surface 



