THE INSECT HEAD SNODGRASS 



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telopodite. The appendage is attached to the body in such a way 

 that its principal motion is in a transverse plane, and its strongest 

 muscles are the adductors {KL). 



The second maxilla (fig. 18 C) has in some respects a more simple 

 structure than the first. The dorsal part of its outer wall is bent 

 toward the articulation with the lateral wall of the body, evidently 

 to give more effectiveness to the groups of adductor muscles {KL) 



Figure 18.- — Mouth appendages of Anaspides tasmamae 

 A, mandibles, posterior view. B, paragnatha, posterior view. C, second 

 maxilla, right, anterior view. D, first maxilla, right, anterior view. 

 E, second maxilla, right, posterior view. a', basal articulation of 

 mandible; a", basal articulation of first maxilla; Bnd, basendite ; Cd, 

 cardo ; Oa, galea ; I, dorsal promoter ; J, dorsal remotor ; k, ligamentous 

 membrane ; KL, ventral adductors ; LB, limb basis ; Lc, laclnia ; IMxStn, 

 first maxillary sternum ; 2MxSt7i, second maxillary sternum ; 0, levator 

 of telopodite ; Pgn, paragnatha ; Q, depressor of telopodite ; Tlpd, 

 telopodite. 



which arise on a sternal plate {2MxStn) in the ventral wall of the 

 body. The basis of this maxilla is thus mechanically differentiated 

 into a proximal part {Cd) and a distal part {St), which may be 

 termed cardo and stipes, respectively, since they suggest the parts 

 so-named in the maxilla of an insect. The maxillary endites of 

 Anaspides {Lc, Go) appear to have no muscles; but the small, one- 

 segmented telopodite {Tl/pd) is provided with two muscles {O, Q) 

 taking their origins in the stipital region {St) of the appendage. 



