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 



Fia. 159. — Mouth of Lepidoptera. Tiger-moth, Arctia caja. A, Seen from front ; B, 

 from front and below, a, Clypeus ; 6, labrum ; c, epipharynx ; d, mandibular 

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

 bosci.s ; /, maxillary palp ; g, labial'palp. 



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

 able, though they, or some prominence possibly connected with 

 them," may frequently be detected in the neighbourhood of 

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

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

 tinguished by him from Micro2:)teryx and was therefore termed 

 " niedere Micropteryginen," 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.^ The mandibles, however, in the vast majority of 

 I^epidoptera can scarcely be said to exist at all in the imago ; 

 there being only an obtuse projection — without trace of 



^ Jena. Zeitschr. 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. ent. Soc. London, 1893, p. 263. 



