8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I23 



jaws lying horizontally in the space between the labrum and the hypo- 

 pharynx (fig. 3 A, Md). Each mandible is articulated dorsally on the 

 base of the clypeus and ventrally on the lower margin of the cranium 

 (fig. 2 B, a), and is provided with the usual four muscles of the man- 

 dible of generalized insects (fig. 3 B), which are a cranial abductor, 



Fig. 3. — Ana.v Junius (Drury), larval mouth parts. 



A, head, ventral, mouth parts in place, labium extended posteriorly. B, left 

 mandible, ventral. C, left maxilla, ventral, articulated on margin of cranium. 

 D, left apical lobe (labial palpus) of prementum. E, maxillary palpus and 

 muscles of adult. 



ar, articular rod of labium ; Cd, cardo ; Lb, labium ; Lc, lacinia ; Lig, ligula ; 

 Pip, palpus ; Pmt, postmentum ; Print, prementum ; slO, opening of salivary 

 duct ; St, stipes. Other lettering as on figure 2. 



2/'t, abductor apodeme of mandible ; 28t, adductor apodeme of mandible ; 

 ^g, hypopharyngeal muscle of mandible ; 30, tentorial muscle of mandible ; 35, 

 36, muscles of maxillary palpus. 



a cranial adductor, a hypopharyngeal muscle, and a tentorial muscle. 

 The cranial muscles are inserted on broad apodemal tendons (■^/t, 

 28t), the hypopharyngeal muscle {2^) arises at the base of the hypo- 

 pharynx (fig. 4C) and expands to its attachment on the lateral wall 

 of the mandible, the tentorial muscle (fig. 3 B, jo) is attached on the 



