308 



LEPIDOPTERA 



CHAP. 



comparatively broad piece, visible on the front edge of the 

 clypeus ; its lateral part usually forms a prominence which has 

 often been mistaken for a mandible ; Kellogg has applied the 

 term " pilifer " to this part. In the middle of the labrum a small 

 angular or tongue-like projection is seen just over the middle of 

 the base of the proboscis ; this little piece is considered by 

 several authorities to be an epipharynx. 



MANDIBLES. Savigny, Westwood, and others considered the 

 parts of the labrum recently designated pilifers by Kellogg to 

 be the rudimentary mandibles, but Walter has shown that this 



FIG. 159. Mouth of Lepidoptera. Tiger-moth, Arctia cajn. A, Seen from front : B, 

 from front and below. , Clypeus ; b, labrum ; c, epipharynx ; d, mandibular 

 area ; d', prominence beneath mandibular area ; e, one side of haustellum or pro- 

 boscis ; f, maxillary palp ; g, labial palp. 



is not the case. 1 The mandibles are usually indistinguish- 

 able, though they, or some prominence possibly connected with 

 them, 2 may frequently be detected in the neighbourhood of 

 the pilifers ; they are, according to Walter, largest and most 

 perfectly developed in Erioceplmla, a genus that was not dis- 

 tinguished by him from Micropteryx and was therefore termed 

 " niedere Micropterygiuen," i.e. lower Micropteryges. The 

 opinion entertained by Walter that Micropteryx proper (his 

 " hohere Micropteryginen ") also possesses rudimentary mandibles 

 is considered by Dr. Chapman, no doubt with reason, to be 

 erroneous. 3 The mandibles, however, in the vast majority of 

 Lepidoptera can scarcely be said to exist at all in the imago ; 

 there being only an obtuse projection without trace of 



1 Jena. Zcitschr. Naturw. xviii. 1885, p. 751. 



; The writer is not quite convinced that the supposed mandibles of these Macro- 

 lepidoptera are really entitled to be considered as such. 

 3 Tr. cnt. Soc. London, 1893, p. 263. 



