( Ivi ) 



segment containing; the ncrvnlar, nuiscnlar, anil vascular apparatus is larger than 

 that of the openings, which serve as doors to tlie cavity. That is especially the 

 case in the segments of the club, as can be seen in fig. 19 of PI. LX., which 

 rcjircsents the left half of a segment, divided sagitally, of the clnb of the 

 antenna of Ilaemorrhagia fuciformis, viewed somewhat from the distal side to 

 show the distal surface. The difference in the jwsition of the axis is illustrated 

 by figs. IT. is. L'.-> of PL LX. 



The fine ciliae are never essentially prolonged in Rhopalocera ; they are 

 also short in some families of Heterocera — for instance in Castniidae and 

 Agarixtiditc. In such cases the two sexes do not differ, or differ only slightly in 

 the antennae. Among tlie Siiliini/id'cc there is only one genus (Rhopalopsyche) 

 in which there are no prolonged ciliae in either sex. Such instances as 

 these are (juite an exception among Heterocera, the antennae of which show 

 generally marked sexual dimorphism. The specialisation refers to the length 

 and arrangement of the ciliae and to the configuration of the ciliae-bearing 

 snrface. 



The ciliae are seldom nearly all jjrolonged and irregularly distributed. Of 

 more common occurience is that specialisation in which some of the ciliae have 

 become long and are arranged in a subapical and a snbbasal vertical row, the 

 two rows becoming fused into one dorso-laterally, forming a kind of flattened 

 half-ring in a lateral asjicct of the antenna. Tiiese seriated ciliae are apparently 

 always fasciculated, two or more ciliae arising from a common tubercle (PI. LXI. 

 f. 1 — 4), or from a common pit. The ciliae of the two rows curve towards each 

 other and project laterally, so tliat they form a kind of pocket in a ventral 

 aspect (PI. LX. f. 15). The apical row does not extend so far ventrad as the 

 basal row, and the ciliae in and near the ventral mesial line are always 

 shortened in Sphingidae. The ciliae of the apical row are shorter than those of 

 the ventral row; comjiare PI. LX. f 17, distal aspect. These fasciculated ciliae 

 as illustrated on PI. LX. are not confined to the Sphingidae ; they are found in 

 yotodontidae, Noctuidae, Arct/idne, etc., etc. However, they occur in all the 

 males of Hawk Moths, exce])t liJiopfilopsi/che, and are also ])resent in a good 

 many females, though they arc here always developed in a lesser degree than 

 in the resjiective males. 



The fasciculated prolonged ciliae are not jiresent on cylindrical antennae. 

 Their aii])earance is always accompanied by a modification of the surface of the 

 segments. The lateral surface encircled by the rows of ciliae becomes flattened 

 or impressed, and the segment dilated ventrad and compressed, appearing some- 

 what jirismatical in a distal or basal aspect (PI. LX. f. IT). The depth of the 

 lateral groove and the length of the ventral projection are very different, not 

 only in various Sphngidae, but also in other Heterocera (PI. LX. f. 17. 25. 27). 

 The ventral projections of the adjoining segments lie either closely together, or 

 are more or less separate (PI. LX. f. 16. 22. 26. 27). The ventral outline of 

 the segment is in most cases nearly straight, but in many Sphingidae and 

 other Heterocera we find the segment sinuate in a lateral view (PI. LX. f. 22. 26) 



