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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



Labnaii, clypcus and cpistoma. — The labrum and clypeus are not 

 evident as separate sclerites. The c])istoma (figs. 4, 5, 7, ep), probably 

 also containing elements of the labrum and clypeus, is not separated 

 from the front by a distinct suture or line. It is present as a ridge and 

 forms the anterior margin of the front. This region is widened later- 

 ally, and is connected with an elevation which surrounds the antenna! 



-OC 



Fig. 4. — Gnathofrichus sulcatus Lee. : Head, lateral aspect. 



An, antenna; Ep, epistoma; E31, compound eye; Fr, frons; Ge, gena; La, labium; Md, 

 mandible; Mx. maxilla: Oc, occipital area; Ve, vertex; a, frontal suture; b, antennal 

 Kroove. 



Cos 



Fig. s.—GnatJwtrichus sulcatus Lee. : Head, dorsal aspect. 



Ac, acciculation; An, antenna; Ep, epistoma; Ey, compound eye; Fr, frons; Md, mandible; 

 Mx, maxilla; Cos, coronal suture; Ve, vertex; a, frontal suture. 



scrobe. In the middle of the anterior margin, an evenly rounded 

 emargination is visible which may be called serratus epistomalus 

 (fig. 7, SE) and which corresponds to Hopkin's median impression. 

 From the serratus epistomalus the acciculation of the front radiates. 

 The epistoma is without sculpture and bears a row of bristles on its 

 posterior margin. The mandibles articulate with the underside of the 

 epistoma. 



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