6 INTKODTJCTION. 



Micropteryx they are non-denticulate and functionless, and in the 

 higher forms rudimentary. In Eriocepliala the free palpi and 

 typical ligula of the mandibulate insects are present, the ligula 

 being formed by the fusion of the inner palps into a short tubule 

 open externally, a short hypopharyns being present on its inner 

 wall. 



0"#' 



Fig. 1. — Head of a Lepidopterons insect from above and from the side. 

 (From Packard's G-uide. p. 232.) 



at. Antennat. 

 c. Clypeus. 

 e. Eye. 



I. ? Labrum or epipharynx. 

 m.p. Maxillary palpi. 

 0. Ocellus. 



ec. Epicranium. 

 oc. Occiput. 



m. Piliger part of labrum. 

 TTUJC. Proboscis. 

 l.p. Labial palpi. 



The maxillary palpi, obsolete in some species, are from 1- to 

 6-jointed in those that possess them. The Micropterygidce have 

 the largest number of joints, six ; in the Tineidcc and Tortricidce 

 the number is very variable ; in the Pyralido' four ; in the Noctuidai 

 generally two, but sometimes three ; in the more specialized families 

 one or two : and in the Papiliones, Sphingidce, and most Geometridce 

 The cases of the maxillary palpi in the pupse are well 



one 



developed in the generalized families, the Tineidce, Sesiadce, Cossidce, 

 and Limacodidce, even when they are aborted in the imago ; in the 

 Pyrcdidce and Zygmiidce they are less conspicuous, and in the 

 more specialized Ohtecto' wanting t- 



The labial palpi are normally well developed and 3-jointed, but 

 aborted or much reduced in the Hepialidce, Psychida', and many 

 Cossidce ; they may be upturned, with the 2nd joint curved, straight 

 and oblique or porrect, or downcurved ; they vary much in form 

 and scaling, the male often having extremely speciahzed develop- 

 ments, but their function beyond that of protecting and cleaning 

 the proboscis is unknown. 



The antennae are sense-organs composed of an indefinite number 

 of joints and varying much in length and structure ; they are 



* A. Walter, Jena. Zeit. Nat. xviii. pp. 121-173 (1884) ; id. Jena. Ges. 1885^ 

 pp. 19-27. 



t Dr. T. A. D. Chapman, Trans. Ent. Soc. 1893, pp. 105-7. 



