Xyloryctidae (Figs. 72 to 77).
Good examples of progressive reduction in the maxillary palpi are exhibited in this large family. Lichenaula has a five-segmented palp; the genera Telecrates, Odites, Procometis, Agriophora, Chalarotona, Scieropepla, Eschatura, Uzucha, and Catoryctis have each lost a segment; Xylorycta and Maroga have only three remaining; Cryptophaga rubescens has two, with a third represented by a minute papilla, while in C. nubila this papilla has been lost. In Neodrepta the third segment is elongate, curved and medially constricted, having all the appearance of being the result of the fusion of the third and fourth. Bearing in mind the shape and size of the apical segment in the majority of the genera, it would appear that reduction has usually taken place by the loss of median or basal segments; and in some genera, i.e., Telecrates, Agriophora, etc., the evidence points pretty conclusively to the basal one as having disappeared. In Neodrepta however, the original basal segment is almost certainly present, and the evidence seems to warrant the conclusion that here the loss of a segment has been brought about by the fusion of two, such fusion
being a preliminary to the shortening of the structure. The cardo and stipes are of normal form and chitinization. The haustellum is short but its two halves are always closely fitted to each other, and the organ is doubtless functional. On the apical half it bears a number of prominent sensory papillae. In Cryptophaga the haustellum shows its greatest reduction, and here also the maxillary palpi are most vestigial.
Species examined: Lichenaula lichenea Meyr., Telecrates laetiorella Walk., Odites pudica Low., Eschatura lemurias Meyr., Chalarotona intatescens Meyr., Scieropepla reversella Walk., Catoryctis eugramma Meyr., Procometes hylonoma., Agriophora confertella Walk., Uzucha humeralis Walk., Maroga unipunctana Don., Xylorycta melaleuca Turn., Cryptophaga rubescens Lew., C. nubila Luc., Neodrepta luteotactella Walk.