338 



THE AXATOMY OF IXYERTEBRATED ANIMALS. 



The head is either flattened from above downward ( Chi- 

 lopoda), or from before backward {Chilof/natha). Some 

 species are blind, but the majority have eyes, which are gen- 

 erally small and not very numerous ocelli, though, in some 

 cases, they are large compound eyes. There is always a pair 

 of jointed antennae. 



The majority have the mouth constructed for biting, and 

 are provided wdth a pair of mandibles, the most important 

 peculiarity of which is that they are jointed, and thus depart 

 less from the type of the ordinary limb than do those of in- 



FiG. QG.—Scolopendra Hopd (after Newport). 



A. Dorsal view of the anterior part of the body : a, antennse ; A, cephalic eegment ; 

 B. basilar segment. 



B. Ventra! view of the head • a, B, as before. 



C. Unfler view of the cephalic segment, showing the antennae, a ; the eyes, *; the 

 labrum and the mandibles, IV. 



D. The second pair of gnathites V, and the first pair of appendages of the basilar 

 Bcgmeut VF. 



sects, while, to the same extent, they approach the gnathites 

 of the Perijyritidea. The mandibles are more modified in the 

 Chilopoda (Fig. 96) than in the Chilognatha. In the latter, 

 the second pair of gnathites form a broad four-lo])ed plate 

 which plays the part of an under-lip, while, in the Chilopoda^ 

 they are soft and jointed, and united at their bases by a bi- 

 lobed median process (Fig. 96, v'). In the Chilognatha the 



