244 HTMENOPTEEA. 



says there is "a triangular central white spot on the abdominal segments"; but 

 the description of the abdominal coloration given by Brulle agrees with our 

 specimen. 



34. Polycyrtus curvispina. 



Ferrugineus, nitidus ; antennis capiteque nigris, ore albo ; antennis annulo albo, tarsis posticis flavis; alis 



liyalinis, stigmate testaceo. 

 Long. 13 millim. 



Hab. Costa Eica, Cache (Rogers). 



Smooth, shining, impunctate. Antennae much longer than the body, pilose ; third 

 joint longer than the fourth. Front depressed between the eyes, the spine stout, 

 longish, conical ; eyes distinctly margined ; face covered with long white hair. Thorax 

 covered with long reddish hair ; mesonotal sutures deep ; a triangular depression at 

 the base of the metanotum in the middle, a transverse keel in the centre ; tubercles 

 long and curved. Abdomen slender, covered (especially at the sides) with long fuscous 

 hair. Areolet large, one half longer than broad, the outer nervure bullated. 



In this species the areolet is much larger than in the other species of Polycyrtus or 

 Mesostenus, but in other respects it agrees with Polycyrtus. If, however, it had not 

 the frontal spine I should almost have placed it in Cryptus. P. atriceps agrees with it 

 "in coloration ; but has the metathoracic tubercles " robust and obtuse," the areolet 

 closed, and is only four lines in length. P. nigriceps, Brulle, also agrees with it in 

 coloration ; but differs, inter alia, in having the tubercles short and conical. 



POLYCENUS. 



Polycenus, Cresson, Proc. Acad. Phil. 1873, p. 149. 



This section differs from Polycyrtus in the front having two small spines, often united 

 at the base, instead of one only. In some species of Mesostenus there are slight indica- 

 tions of these spines, while Polycenus agrees with the latter in the lobes of the mesonotum 

 not being well developed as in Polycyrtus. The known species are comparatively few 

 in number. 



1. Polyaenus ectypus. 



Polycenus ectypus, Cresson, Proc. Acad. Phil. 1873, p. 149 ( $ ) \ 

 Hob. Mexico, Orizaba x (Sumichrast). 



2. Polysenus ablatus. 



Polycenus ablatus, Cresson, Proc. Acad. Phil. 1873, p. 149 (? ) \ 

 Hab. Mexico, Orizaba 1 (Sumichrast). 



