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All the gulo-mental region of the head appears to represent the base of the second maxillæ, and the question hence arises whether the submentum is not the homologue of the cardines of the first maxillæ fused, and the mentum that of the stipites of the latter also fused together. If this should prove to be the case, the homologies between the two pairs of maxillæ will be still closer than before supposed. Where the gula is differentiated, this represents the basal piece of the second maxillæ. In Figs. 28, 29, 30, and 31, these three pieces are clearly shown to belong to the second maxillary segment. It is evident that these pieces or sclerites belong to the second maxillary or labial segment of the head, as does the occiput, which may represent the tergo-pleural portion of the segment. Miall and Denny also regarded the submentum as the basal piece of the second maxillæ.

Fig. 30.—Head of Mantispa brunnea, under side: e, eye; other lettering as in Fig. 29.

Fig. 31.—Head of Limnephilus pudicus, under side: e, eye; l, ligula; p, palpifer; lp, labial palpi.