Horn. J 



TANYMECINI. 



81 



while in the latter the maadibles are always greatly exposed above. A 

 lateral view of the beak will therefore show the tip to be obliquely trun- 

 cate in those with the emarginate genae, and squarely truncate in the other 

 case. 



The scar of the deciduous mandibular cusp is very distinct in all the 

 genera excepting Coleocerus, and is usually on the face of the mandible, 

 although in some genera at the summit of an obtuse process. 



The tribes forming this division are shown in the following table : 



Mentum moderate, rarely small, never retracted; 



sub-mentum not notched at middle ; thorax 



rarely {Pachnwus) with feeble ocular lobes. 



'Eyes round . 



Thorax fimbriate at the sides behind the eyes. 



Striae entire TANYMECINI. 



Thorax not fimbriate at the sides behind the 

 eyes. 

 Genaj emarginate behind the mandibles. 

 Rostrum short, robust; tenth striae conflu- 

 ent with the ninth ; claws free, ex- 

 cept in Apfirastus CTPHINI. 



Genae not or very feebly emarginate ; tenth 

 striae free. 

 Rostrum at least moderately elongate, 

 scrobes long ; claws free ; head not 

 prolonged behind the eyes ; articular 

 surfaces of hind tibiie cavernous . Men- 

 tum large EXOPHTHAI,MIJiI. 



Rostrum rather short, scrobes short ; head 

 prolonged behind the eyes ; claws 

 connate ; articular surfaces of hind 



tibiae open. Mentum small PHTttOBIINI. 



Mentum small, retracted ; thorax with large 



ocular lobes. Eyes transversely gval promecopi.^i. 



The partial obliteration of the marginal stria occurs in but one tribe, in 

 the others that stria is entire and nearly equallj^ distant from the pre- 

 ceding throughout. The mentum attains the minimum in the last two 

 groups. 



Tribe I. tabtymecini. 



Rostrum moderate, sub-angulate, sub-parallel, more or less emarginate 

 at tip and at the sides. Scrobes moderately deep, arcuate, passing beneath 

 the eyes. Antennae moderate, scape moderately long, usually attaining 

 the hind margin of the eye, sometimes attaining the thorax. Thorax witli 

 a short row of bristly hairs behind the eyes (and in Pachnceus very feebly 

 lobed). Scutellum distinct. Metasternum moderately long. Second seg- 

 ment of abdomen longer than the third and fourth together, and separated 



PROC. AMER. PHILOS. SOC. XV. 96. K 



