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that is uot covered Nvith scales densely beset with long fine sense-hairs, dorsal and 

 ventral side of the antenna being alike in this respect (as well as iu other 

 characters). No Freuate Heterocenihiivefine sense-hairs dorsally. Among Butterflies, 

 however, we find tliem again on the dorsal side, and this fact is of higli significance, 

 all the distal joints that are not scaled above of certain Li/cueiiidae {Aihojjula) 

 being equally covered all over with fine sense-hairs. No members of other Butterfly- 

 families have this character. 



In the remainder of the Lepidoptera the fine sense-hairs wvwr only 

 ventrally; such a type we find also among Hepialulae, besides the first type. 

 The Heterocera without exception, as far as I know, have the uot-scaled 

 ventral area covered all over with these hairs, inclusive of the branches of 

 pectinated antennae : the hairs are, however, often of different length on the same 

 joint. Such a uniform distribution of the fine hairs obtains among Rhoi>alocera in 

 all species of Ilexperiidae and Li/caenidae, anil in the females (not males) of certain 

 Papilios {poli/tex and allied forms). In all the other Butterflies the hairs are 

 restricted in extent. In Eri/cinidae the restriction is only indicated by the hairs 

 being sometimes denser in the impressed middle of the joint than laterally: in 

 Pierinae we have a further step in the same direction, the hairs being in this 

 subfamily of Pieridae restricted to a middle groove, while in Diamorfihiiiia£ the 

 hairs are placed into three grooves. The Papilionidae with restricted extent of 

 sense-hairs present three difi'erent types : in the first the hairs are confined to the 

 base of the joint, forming one more or less large patch, wliich is often deeply 

 sinuate in the middle ; in the second tjqje the hairs are jjlaced in an irregular 

 groove (Parnassiinae) ; while in the third type the hairs are restricted to two 

 grooves, standing at each side of the mesial line or being more lateral. This latter 

 mode of distribution is constantly found iu all the species of -X'/mp/'alidat', where 

 the restriction is carried often so far that there is only a small round patch of short 

 hairs (iJa/iainae, for instance) in each of the two ventral grooves we find iu this 

 family ; sometimes only a few sense-hairs are present (Brassolis, Tripliysa). It 

 is a general rule that, within the same group of genera, the fine sense-hairs are 

 longer in the species where they are less restricted in number and extent, and that 

 they are also longer and less restricted on the stalk than on the club. Sometimes 

 they are restricted on the club, but cover the whole uot-scaled area of the joints of 

 the stalk (^Leplovircm). 



c, Setiferons Punctures. — The auteuuae with restricted scaling and hue sense- 

 hairs are, at least iu Butterflies, in the places which are not occupied either by 

 scaling or fine hairs, more or less densely covered by setiferous punctures. This 

 sensory organ seems to be absent from, or very scarce in, the Butterflies and Moths 

 with evenly distributed fine sense-hairs, while the jiuucturation is very prominent, 

 especially at the sides of the joints, in the Butterflies with highly restricted sense- 

 hairs and scaling (^Ni/mphalidae, Papilionidae). The dorsal surface of the not- 

 scaled joints has generally a mesial stripe that is bare of setiferous punctures; but 

 there are instances in which the whole dorsal surface (except the most proximal 

 joints) bears such j)uncturation all over, a kind of distributiwn which reminds one 

 strongly of the distribution of fine sense-hairs over the dorsal surface of the distal 

 joints of certain Lycaeiddac and of the whole antennae of certain Jlepialidae 

 {Hepialas, for instance). In some Papilionidae, especially in Parnassiinae, the 

 fine sense-hairs are often so short that they resemble the hairs of the ])uncture8 

 very much As the fine sense-hairs are doubtless dift'ereut iu function from the 



