77 



A study of the head of the perfect moth shows that it is composed of several distinct 

 chitinous pieces protecting the nervous ganglia, and covering the mouth parts which are 

 only fitted to take in liquid food. At the base of the spiral tongue (spirilingua) are 

 placed the jointed maxillary palpi, (Fig. 35) but these 

 are often, perhaps usually obsolete; they are well 

 developed in the snout moths or Pyralidce, and 

 especially in certain Tineidce. On the other hand all 

 moths possess one pair of labial palpi, jointed appen- 

 danges, analogous to the legs in ultimate structure and 

 articulated to the lower lip or labium. The space 

 between the eyes is called the front or clypeus, and this 

 piece varies in comparative shape and size in the differ- 

 ent families, and often affords peculiar structure offer- 

 ing generic characters. In the genus Eudryas, for 

 example, (Fig. 36) it is smooth, and in the related genus Gopidryas it is 



provided with a clypeal horn. The compound 

 eyes vary in shape and external appearance. They 

 are sometimes constricted, as in certain Heliothid 

 genera in the Owlet moths. Again the surface, usually 

 naked, is covered with short hairs arising from the 

 angles of the facets apparently, and only to be properly 

 observed under the microscope. Behind the eyes the 

 small ocelli, or simple eyes, are to be found ; these are 

 never more than two in number, and are sometimes 

 wanting, as in the genus JBrephos. The antenna?, or 

 " feelers," are situated on the top of the head on each 

 side, and spring out between the vertex and epicranium. The basal joint is often 

 thickened and longer than the rest. Up to 100 joints have been rounted in the antennae 

 of some moths. They vary much in ultimate structure and exhibit sexual peculiarities, 



Fig. 37. 



being more prominent in the males, feathered, pectinated or ornamented with nodosities* 

 The extremes in total length are apparently afforded by the genera Adela, where they are 

 longest and Hepialus where they are shortest. They are broadest and most plumose in 

 the genus Attacus (Fig. 37.) The average aspect of these organs in the moths may be 



