116 BULLETIN: MUSEUM OF COMPAEATIVE ZOOLOGY. 



chitiuous stalks, all of which distinctly ai'e as in Collembola, Campodea, 

 and Japjx, except that the superliuguaj of Hemimerus appear to be 

 fused with the lingua. Figure 10 of Hansen bears a close resemblance 

 to my Figure 27 of Anurida, although Hansen says (p. 87), "especially 

 the structure of the mouth removes it [Hemimerus] very far [?j from 

 the Thysanura and leads it to the Orthoptera." 



In the young larva of Ephemera, Heymons ('96, p. 22, Taf. 11. 

 Figur 29) finds that " Der Hypopharynx entsteht . . . auf ahnliche 

 Weise wie bei den Orthoptereu. Auch an ihm findet eine Art Gliede- 

 rung statt, dergestalt, dass von der eigentlichen Hauptmasse zwei laterale 

 vordere Zapfen abgetrennt- werden, die mit kleinen Hitrchen bedeckt 

 sind, wahrend der eigeutliche Hypopharynx am Ende einen Besatz von 

 feinen (Sinnes-) Borsten tragt." His figure of lingua and superlingure 

 might fairly represent those structures of Anurida in Stage 7 (Plate 4, 

 Figure 27). In the imago the mouth-parts are, of course, atrophied. 

 In another Ephemerid nymph, Heptagenia, Vayssiere ('82, pp. 113- 

 114, Planche 5, Figure 46) found a highly developed lingua, or hypo- 

 pharynx, fused with large lateral pieces [superlinguaj] and suggests that 

 they indicate a distinct primitive segment, — a possibility which will be 

 discussed later. He states (p. 106), ** La langue ou hypopharynx . . . 

 est assez develope chez tons les individus de la famille des Ephemerines, 

 a I'exception du Prosopistoma, oh il est tres rudimentaire." 



I shall not cite descriptions of the " hypopharynx " of additional in- 

 sects, because I have nothing more to add, and the subject has been 

 well treated of by Kolbe ('SO, pp. 213-217, Figuren 126-134), Packard 

 ('98, pp. 70-83, Figures 70-87), and others. Packard's comparative 

 account, in particular, is most excellent and well illustrated. (In his 

 Figure 69, by the way, the abbreviations 7^. and h//p. should be inter- 

 changed.) Briefly, the lingua is found in every order of insects, and 

 although highly specialized in suctorial orders, retains, nevertheless, the 

 same position and nearly the same relations to the salivary ducts that 

 it does in the more generalized mandibulate orders which I have de- 

 scribed. It is an interesting fact that in the Lepidopterous genus, 

 Micropteryx, "Walter ('85, Taf. XXIV. Figur 11) shows two hypo- 

 pharyngeal stalks, readily comparable with those of Apterygota. 



Tlie superlinguoe — which, as I have shown, originate quite indepen- 

 dently of the lingua in Apterygota, but become more or less united with 

 it in Orthoptera and Ephemerida — should hereafter be recognized as 

 nun-phologically important structures, and be searched for in even the 

 most specialized haustellate orders as more or less intimate constituents 



