CEPHALOIDAE. 405 



5. Eyes feebly emarginate. Nacerdes. 



Eyes deeply emarginate. Xauthochroa. 



(J. Claws simple or obsoletely toothed. 7. 



Claws strongly toothed at base. O. 



7. Mandibles bitid at tip. Copidita. 



Mandibles acute at tip. ^_ 



b. Front prolonged into a broad beak. Rhinoplatia. 



Front not prolonged. Oxacis. 



It. Mandibles acute at tip. Probosca. 



Mandibles bifid at tip. Asclera. 



Microtonus is founded on a very small brown sericeous insect, 

 found on leaves in the Atlantic States. The last joint of ilie 

 palpi is large and securiform ; the antennae are inserted at a small 

 eniargination of the eyes, are slender, one half the length of the 

 body, with the 2d joint one-third as long as the following one; 

 the eyes are comparatively large, widely separated, and tolerably 

 coarsely granulated; the front is crossed by a very distinct curved 

 suture, just before the eyes ; the penultimate joint of the tarsi 

 is very slightly bilobed. The species 31. sericans Lee. is small 

 (.10-. 15 unc. long) and slender, brown, densely punctured, and 

 clothed with short sericeous pubescence ; the thorax is as wide 

 as the head, nearly square, feebly bisinuate at base, with the hind 

 angles subacute, very feebly rounded on the sides, and generally 

 vaguely impressed near the sides behind the middle. 



Fam. LXVII.-CEPHALOIDAE. 



Mentitm snaall, nearly square, supported b}'' a gular pro- 

 cess; ligula membranous, broad, bilobed, prominent; labial 

 palpi small, 3-jointed. 



Maxillae with the base large and prominent, and two long 

 slender lobes ciliate at the tip; palpi 4-jointed, last joint tri- 

 angular, ol)liquely truneate. 



Head inclined, large, rliomboidal, gradually narrowed be- 

 liind the eyes, suddenly constricted at base, inserted into the 

 thorax by a not very slender neck; eyes small, reniform, 

 finely granulated; mandibles small, acute at tip, subserrate 

 on the inner margin with a broad membrane extending from 

 the base half the length ; labrum prominent; frontal suture 

 not distinct. 



Antenme inserted at the .sides of the front, under a small 



