folsom: mouth-parts of axurida maritima. 131 



als sehr kleine unscheinbare Vorsprllnge erkennbar, welche medialwarts 

 an der Basis der Taster hervorwucheru." This is contrary to the condi- 

 tions in Anurida, where the palpus is certainly itself an outgrowth from 

 the simple, primary papilla (Figure 13). Lepisma agrees with Anurida, 

 however, in that the galea and lacinia are derived from the inner lobe of 

 a biramous fundament (Heymons,' 97% Taf. XXX. Figur 17), and dis- 

 agrees with Campodea if, in the latter genus, as Uzel implies, the galea 

 buds from the palpus. The finished labium of Lepisma, as I shall show, 

 is remarkably like that of Orthoptera. 



The labium of Machilis, as described by Oudemans ('88, pp. 185-186, 

 Taf. II. Figuren 28, 29), resembles that of Campodea and Collembola in 

 being deeply cleft, and having the salivary ducts opening in similar posi- 

 tions, but it more nearly approaches the Orthopteran type in the position 

 and structure of the terminal lobes, the mentum, and the three-jointed 

 palpi. Each terminal lobe is subdivided into four lobes, which in all 

 probability collectively represent galea and lacinia. 



Ayers ('84, p. 211, Plate 18, Figures 20-22; Plate 19, Figure 5), as 

 already quoted (p. 121), has traced the development of the second maxillae 

 of (Ecanthus as far as the trilobed stage, stating the lobation to be more 

 prominent in the second than in the first maxillary appendage. The 

 fact that the second maxillse of Anurida develop upon the Orthopteran 

 type is important. In Lepisma, the trilobed fundaments agree with 

 those of Orthoptera even as to the greater length of the palpus. 



In the finished labium of (Ecanthus (Packard, '83% Plate XXVII. 

 Figure 9) the derivatives of each trilobed fundament are easily identified 

 as three-jointed palpus, galea, lacinia, palpifer, and mentum, — the last 

 two structures having doubtless arisen from the common stalk, or stipes. 

 Although the labium is constructed upon the same plan in all Orthoptera, 

 we may best select Blatta for comparison with Lepisma. The agreement 

 between Blatta (Muhr, '77, Taf. IT. Figur 11; Packard, '83% Plate 

 XXVII. Figure 14) and Lepisma (Muhr, '77, Taf. VIII. Figur 46 ; 

 V. Stummer-Traunfels, '91, Taf. II. Figur 17) is surprising. Galeae and 

 laciniae clearly correspond in the two, as do the mentum, palpifers, and 

 palpi, the last, however, having three segments in Blatta and four in 

 Lepisma. Muhr, in fact, included Lepisma among Orthoptera, as have 

 some other authors. 



It is now agreed that the first and second maxillae of Orthoptera are 

 hemodynamic, and, more inferentially, that the same is true of other in- 

 sects. The exact agreement first recognized, according to Packard ('98, 

 p. 69), by Miall and Denny ('86), was detected long before, at least, by 



