( liv ) 

 scales. A furtber confirmation df (lie view jnt^t i'.\iiresseil, that the ventral 

 scaling of the antenna is a relatively yonng character, we find in the fact that 

 there are sometimes scales on the nnderside of the antennae of hybrids where 

 there should not be any, these scales being donbtless an expression of weakened 

 vitality. We jircdict that by breeding in and in specimens will result which 

 show a more extended antennal scaling than the normal individuals. The 

 antennae of the Aiuiei-iidac and ("asfiiiiilac, which resemble in general appear- 

 ance somewhat a clabbcd Sphingid antenna, ditier essentially from the latter 

 in bavins: the L'reater part of the ventral surface scaled, agreeing in this respect 

 with the antennae of a great many Timiihr. Among the latter family (or 

 group of families, perhaps), and among the IJmacodidai; we Hnd antennae which 

 are almost entirely covered with scales. 



Before following the somewhat complicated development of the sensory 

 surface, we shall shortly refer to the sense-cones and sense-bristles. The sense- 

 cones discovered by Bodine do not occur in Khopalocera, but are widely distriliuted 

 in Heterocera. Tliey are ventral, mesial, and apical in Sphingidae, one on each 

 segment, except the end-segment and the basal one or ones (PI. LX. f. 4—29, ec), 

 from which they are absent. The cones of the distal segments are generally 

 more prominent than those of the proximal segments. They do not always 

 stand exactly at the apical edge of the segment, being not rarely removed 

 somewhat basad (compare, for instance, Herse comolvuli). However, they are 

 never absent and never abandon the mesial position in this family. They 

 are wanting in the ('astidkhie, Aegeriidae, and Zgyaenidae ; their absence is a 

 distinctive character not difticnlt to recognise. They are present on the clubbed 

 antennae of Agaris/idae and Coci/tia. 



The sense-bristles are stiff hairs of varying length. The Lepidoptera most 

 primitive in respect to these organs have a complete belt of such bristles on 

 each segment. Among Rhopalocera we find such a belt preserved in LijcaeuidM 

 and Ilettperiidne ; we meet with it again among the Jiigafa and many Hetero- 

 cerons Frenata. Some of the dorsal bristles are, however, generally reduced aud 

 covered by the scaling. This is the case also in Sphingidae. The normal 

 number of the bristles found in the Ifawk Moths on the non-scaled surface, if 

 we except the end-segment, is two on each side (PI. LX. f. 14), one being dorso- 

 lateral, the other vcntro-latcral and basal. The number is sometimes doubled ; 

 but there is never a complete transverse series, and the bristles are never apical, 

 the Sphingid antenna differing therefore obviously from that of Agaristidae, 

 Zygaenidae, and many other clubbed and non-clubbed antennae. 



The <lorso-lateral bristles situated close to the edge of the scaled area are 

 very often so prolonged and become so stout that the antenna has the appearance 

 of being pectinated ; in fact, that bristle has often been mistaken for a pectina- 

 tion.* We meet with this development very commonly in filiform and setiform 

 antennae, but never among Sphingidae. 



The ventral and lateral surface of the antenna of Heterocera, as far as 



• Nor. Zool. iii, t. !. f. 5—11. 



