VI 



ANTENNATA MOUTH PARTS 



447 



Myriapoda. 



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

 maxillse with only 1 masticatory ridge and rudimentary feeler. The Pauropoda 

 have similar mouth parts also weakly 



developed. The mouth parts of both /y %k. *rK / V 



groups require further investigation. 



Chilopoda (Fig. 304). The mouth 

 parts, apart from the upper lip and 

 the hypopharynx which belongs to 

 the lower cesophageal wall, consist of 

 the typical limbs, mandibles, anterior 

 and posterior maxillse. The anterior 

 pair of maxillse has well developed 

 masticatory ridges, but has no feeler 

 or only a rudimentary one. The 

 feelers are well developed on the 2d 

 pair of maxillse, but the masticatory 

 ridges are wanting. The basal por- 

 tions of these maxillae are sometimes Fi - 304.-Lithobius validus. The head from 



below after removal of the maxillipedes (after Latzel). 

 separate, sometimes fused. a> Antenn83 ; sk> f ron tal portion of the cephalic shield ; 



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

 here complicated and difficult to ex- pair of maxillse ; stl, stems of the same fused in the 

 plain. The powerful upper law is middle line ; sto, stems of 1st pair of maxillse ; me, ?m, 

 ,. -11 I, ,, , ,. / .1 outer and inner ridges of the same, 



followed by the lower lip (gnatho- 



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

 1 pair of maxillse. 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 

 maxillse (lower lip), and the 2 lateral 

 pieces each provided with 2 masti- 

 catory ridges with the stem portions 

 of the anterior maxillse, the palps 

 being absent. Although this last 

 view, which rests upon analogous 

 modification of the 2 pairs of maxillse 

 in certain beetle larvse (Elateridce), 

 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 

 Fig. 305.-The Gnathochilarium of Lysiopetalum Dipl ^ poda are sai d to come from the 

 carmatum (Diplopoda, after v. Rath), mx,, Stem of *.* 



the anterior ; mz 2) of the posterior maxillae (?) ; me and rudiments of 2 pairs of feet. A corn- 

 mi, outer and inner masticatory ridges of the anterior parison of the mouth parts of the 

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

 Cower lip). basig ig urgen tly needed. 



Hexapoda. 

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



mx 



