VI 



A NTENNA TA MO UTH PA /,' 7',s' 



447 



Myriapoda. 



Symphyla. Mouth parts for chewing. Upper lip, mandibles, and 1 

 maxilla' with only 1 masticatory ridge and rudimentary feeler, 

 have similar mouth parts also weakly 

 developed. The mouth parts of both 

 groups require further investigation. 



Chilopoda (Fig. 304). The mouth 

 parts, apart from the upper lip and 

 the hypopharynx which belongs to ml 

 the lower cesophageal wall, consist of 

 the typical limbs, mandibles, anterior 

 and posterior maxillfe. The anterior 

 pair of maxillfe has well developed 

 masticatory ridges, but has no feeler 

 or only a rudimentary one. The 

 feelers are well developed on the 2d 

 pair of maxillfe, but the masticatory 

 ridges are wanting. The basal por- 

 tions of these maxillfe are sometimes 

 separate, sometimes fused. 



pair of 

 The Pauropoda 



Fig. 304. Lithobius validus. The head from 

 below after removal of the maxillipedes (after Latzel). 

 a, Antennas ; sk, frontal portion of the cephalic shield ; 

 Diplopoda. The mouth parts are O c, grouped ocelli ; pi, feeler of lower lip or of the 2cl 



pair of maxilla; ; stl, stems of the same fused in the 



middle line ' sim > f ms f f , lst P air of maxillie ; me ' mi > 

 outer and inner ridges of the same. 



here complicated and difficult to ex- 

 plain. The powerful upper jaw is 

 followed by the lower lip (gnatho- 

 chilarium, Fig. 305). This lower lip is said by some observers to consist of only 

 1 pair of maxillfe. Others explain the pieces represented in the figure in such a way 



that the paired halves of the middle 

 piece, each of which is provided with 

 a masticatory ridge, correspond with 

 the stem pieces of the posterior 

 maxillfe (lower lip), and the 2 lateral 

 pieces each provided with 2 masti- 

 catory ridges with the stem portions 

 of the anterior maxillfe, the palps 

 being absent. Although this last 

 view, which rests upon analogous 

 modification of the 2 pairs of maxillfe 

 in certain beetle larvfe (Elaterid"'\ 

 is preferable from the point of view 

 of comparative anatomy, it is not 

 yet quite certainly established. The 

 developmental history, as far as it is 

 as yet known, seems rather to support 

 the first view, since the mandibles 

 and the gnathochilarium of the 

 Diplopoda are said to come from the 



,. ,, cc A 



diments of 2 pairs of feet. A com- 



Fig. 303.-The Gnathochilarium of Lysiopetalum 

 carinatum (Diplopoda, after v. Rath), ma*, Stem of 

 the anterior ; ,*,, of the posterior maxffl* (?) ; m and 



mi, outer and inner masticatory ridges of the anterior pai'ison of the mouth parts of the 

 maxilke ; m, masticatory ridge of the posterior maxillae Myriapoda on a new ontogenetic 

 (lower lip). 1 ias j s j s urgently needed. 



Hexapoda. 

 Apterygota. The mouth parts of the Apterygota are adapted for mastication N 



