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Fig. 76.—Hypopharynx of Eriocephala calthella: lig, ligula, its membranous hinder edge; lig′, anterior horny edge of the ligula-tube opening outwards; hp, contour of the hypopharynx; mi, mala interior (lacinia); me, mala exterior (galea), of second maxilla; mx′ p, labial palpus.—After Walter.

The spinneret of the larvæ of Lepidoptera is evidently the homologue of the hypopharynx of insects of other orders. It will be seen that the homology of the different parts is identical, the common duct of the silk-glands opening at the end of the hypopharynx, which here forms a complete tube or proboscis extending beyond the end of the labium, in adaptation to its use as a spinning organ.

Walter refers to Burgess’s discovery of a hypopharynx in Danais archippus, remarking that this organ in the adult Eriocephalidæ (Fig. 76) exhibits a great similarity to the relations observable in the lower insects, adding:—

Fig. 77.— Labium of Micropteryx anderschella seen from within (the labial palpi (mx.′ p) removed to their basal joint). Lettering as in Fig. 76.—After Walter.