MOTHS AND BUTTERFLIES. 



469 



sound similar to the squeaking of a mouse ; but the means by which this noise is made 

 no one has definitely ascertained. This insect has been regarded in some countries 

 by the superstitious as an evil omen. Its large size, i:)0werful flight, the weird skull- 

 like mark on the thorax, and the "peculiar, plaintive sound" which it emits, have all 



Fig 502. — Achtrontia aUopo , deitli & he id moth 



conspired to render it an object of alarm to the ignorant; and, on the Isle of France, 

 the opinion once prevailed among the common people that the dust cast from its wings 

 in flying through a room would produce blindness if it hapjDened to fall on the eyes. 



C. H. Ferxald. 



Sub-Order II. — Rhopalocera. 



The line drawn Ijetween the butterflies and the moths is a rather arbitrary one, the 

 most prominent difference being that, in the group now under discussion, the antennte 

 are alw.ays knoblied at the extremit}^, though in some forms they are nearly as filiform 

 as in some moths, while, on the other hand, some of the moths have these organs 

 almost club-shaped. None of the butterflies have the fi-cn- 

 ulum, a bristle uniting the two wings, as do many moths. 

 The eggs of butterflies are usually more complicated and 

 ornamental in their outline than those of the moths. The 

 larvse are all external feeders, and do not spin cocoons, 

 but transform into the chrysalis state b)^ suspending them- 

 selves, either liy the tail or by a silken thread or band 

 around the centre of the body, while the perfect insects 

 invariably fly by day, and are hence called Diurnals. Not, however, that all the 

 moths fly by night. Many of them are day-fliers, and a few families wander abroad 



Fig. 593. — Head of butterfly. 



