INTKODUCTIOK 13 



and the end of their trunk (as has been well shown by Mr. F. Darwin 

 in the case of the Australian OpMderes fullonica, which penetrates even 

 the rind of oranges) is bayonet-shaped and armed with saw-like teeth 

 and ridges. 



The antennae of Lepidoptera have the characteristics of being well- 

 developed and many-jointed throughout the Order, and in the great 

 majority of genera long and conspicuous. The shortest antennse are 

 found in the Moths known in England as " Ghosts " and " Swifts " 

 (family Hcpialidce)^ and the longest in the so-called " Long-Horns " 

 among the smallest Moths (family Tincidce). Their form varies greatly, 

 from the simple thread-like (filiform), or gently tapering (setiform), to 

 the doubly comb-toothed {hijMctinatc) or feathered (jplumose). Their 

 office has not yet been certainly made out ; they do not appear to be 

 employed as many insects of other Orders use them, viz., as feelers or 

 organs of touch ; but, if they are the seats of any special sense, it seems 

 probable, from the fact of their being, in very many cases, much more 

 highly developed in the male sex, that they are olfactory.^ The pro- 

 minence of the antennge and the facility with which they can be 

 examined, no less than the fact that their various forms are very 

 characteristic in the main of certain large natural groups, have led to 

 the employment of these organs as representative ones in separating 

 and naming the divisions of the Order. Dumeril, in 1823, proposed 

 four such divisions ; of which the first, Eopaloceres, comprised the Butter- 

 flies or Clubbed-Horns, having the antenn£e knobbed or thickened- at 

 the tip ; the second, Closteroccrcs, the Moths whose antennee are thickened 

 about the middle (fusifor'ni), included the Sphinges or Hawkmoths ; 

 the third, Nematocercs, or Thread-Horns, contained the Bombyces ; and 

 the fourth, CMtocercs, or Bristle-Horns, was composed of all the remain- 

 ing Moths. The last of these divisions was a most heterogeneous 

 assemblage, and neither it nor the two preceding divisions (which are 

 comparatively natural ones) have been adopted by any lepidopterist ; 

 but the first, Ehopcdoccra, was accepted by Boisduval in 1836, and by 

 Westwood in 1840. The former of these authors professed himself 

 unable to separate the Sphinges from the other Moths as a primary 

 division of the Order, and united all Dumc^ril's three groujDS into one, 

 which he styled Hcterocera, or Varied-Horns ; and in this also he was 

 followed by Westwood, who stated that he could not admit the minor 

 divisions of the nocturnal Lepidoptera " to a rank equivalent to that of 

 the whole of the Diurna." This simple partition of the Lepidoptera 

 into the two great groups of those with clubs or terminal thickenings 

 of the antennge, and those without them (however variable the organs 



^ It is noteworthy that the antennae are very highly developed in the males of those 

 Bomhycidce which so readily discover the sedentary female under circumstances (such as 

 enclosure in a shut box) which seem to preclude the employment by them of any but a sense 

 of smell of extraordinary keenness. That this sense is the one exercised seems to be proved 

 by the fact (to which I can testify in the case of Lasiocampa Qiiercus) that males are 

 attracted by the empty box from which a female has been removed. 



