( Ivii ) 



to a more or less obvious degree. Such serrate antennae are not rarely fonnd 

 among the Avihnlicinae. The sinnons ventral outline does not occur in clnbbed 

 antennae, in which also the lateral grooves are less deep and less large 

 than in nou-clnbbed antennae. 



A step further tlian the ordinary fasciculated antenna is that in whicli 

 pectinations make their appearance. As there are no fasciculated antennae among 

 lihopalocera, so there can be no pectinated ones, as the latter type is a derivation 

 from the former. We are accustomed to speak of pectinated antennae, if the 

 segments have lateral expansions or branches. The term comprises, however, 

 morphologically very different elements. Among Sphngidae there occur only 

 two kinds of pectinations, and these alone we shall deal with. We see from 

 tig. K) of PI. LX. that the dorso-lateral part of the segment just above the 

 groove is somewhat dilated laterad ; the expansion is more distinct in a frontal 

 aspect (PI. LX. f 17). If this dorso-lateral expansion becomes more or less 

 jirolonged, we have a strongly or a slightly pectinated antenna of the form 

 represented by figs. 23. 27. 28. 29 of PI. LX. If the scaled dorso-lateral area 

 takes ]iart in the expansion, tlie side-branches are scaled above (PI. LX. f. 2!)) ; 

 if the exjiansion is restricted to tlie non-scaled area, the pectinations are naked 

 above. Comparing figs. 16. 17. 23. 27, it will be obvious that, the branches 

 being lateral expansions of the upper edge of the grooves, the ciliae are naturally 

 confined to the under surface of the pectinations. This type of pectination is 

 (if wide occurrence, being met with in many families of Heterocera, and is easily 

 distinguished from another type, not found in Sphingklae, which has the ciliae 

 all round the side-branches. At the tip of the branch we find generally a 

 prominent sensory bristle (Nov. Zool. iii. t. 4. f. 3. 4), corresponding to the 

 dorso-lateral bristle of setiferous antennae. The pectinations of Sphingid antennae 

 have no such bristle at the ends. Rudimentary (= inciijient) pectinations are 

 rather often observed among Amhulicinae (= Ambuh'cinae + Smerintkiivie of 

 Butler), while distinctly pectinate antennae are rare ; PI. LX. i. 28. 29 represent 

 those in which the branches are longest, one an Ambulicine species, the other 

 an ally of Macroglossum. In the latter species the branches of the inner 

 (anterior) side are somewhat longer than those of the other side. Such 

 asymmetrical development is very common in the antennae. 



Tlie second type of pectinated Sphingid antenna is illustrated by figs. 1 — 5 

 of PI. LXI. In figs. 1 and 2 {Polypti/chus mutata) we ser the dorso-lateral 

 expansion ((llj>) well develoj)ed, and observe that its underside bears a number 

 of fascicles of ciliae. These ciliae stand mostly upon tubercles like the more 

 ventral fascicles, and the ventro-lateral tubercles are seriated and are situated 

 upon a slightly raised carina (yc). If these two carinae, one apical and the 

 other basal, become higher and higher, or are produced laterad, what will be 

 the result ? We shall have a segment with two processes on each side, the 

 processes being compressed and bearing like the carina the fasciculated ciliae 

 at the narrow edges, not upon the flat vertical sides (PI. LXI. f. 3. 4. 5). This 

 very peculiar type, which comes close to the type fonnd in most Saturtiiidae 



