NO. 2178. THE OENUS BRACON FABRICIUS— MORRISON. 311 



Tho beak is made up of the two maxillae and the labium, which 

 are united to each other by membranes. All of the parts are elon- 

 gated, particularly the sclerites of the maxillae. The relative thick- 

 ness and length of the maxillary and labial palpi vary in the different 

 species, but not greatly enough to be of value for identification. An 

 idea of the general appearance of the beak may be obtained from 

 plate 25, figures 4 and 5. With the possible exception of the labrum, 

 none of the mouth parts appear to show any variations large enough 

 to be considered as of use in distinguishmg species. 



Thorax. — The thorax is somewhat longer than high, compressed, 

 and about as wide as the head. The pronotum is very narrow in 

 front and widens out on each side mto a triangular lobe reachmg 

 back to the tegula and downwards to the insertion of the fore coxae. 

 Typically there is a pair of small oval pits, each tapering to a point 

 below and surrounded by a more or less distinct ridge, which contmues 

 downward to the front margin of the lobe, on each side of the median 

 line and separated from each other by a distance about equal to the 

 length of one pit. These pits are deepest at the top and gradually 

 become shallower and narrower below, w^hile they are connected by a 

 more or less distinct suture which is either curved or obtusely angled 

 toward the oephahc margin of the pronotum on the median line. 

 In one species these apical pits are replaced by a large deep transverse 

 groove. The hinder, lower, and front margins of the pronotal lobes 

 are elevated to form a narrow ridge running from the spiracle below 

 the tegula on one side around to that on the other. The front margin 

 of each lobe is interrupted a httlc above its middle by the intrusion 

 of the carina from the pronotal pit, this ridge being much more 

 promment than the one bordering the lobes. The face of each lobe is 

 depressed along a straight line running from the apical pits to the 

 lower corner of the lobe in such a way that the whole hinder por- 

 tion of the lobe forms one face of the very flat groove and the cephalic 

 border flares sharply to form the other face, this depression being for 

 the reception of the fore femora. A shallow crenulate groove parallels 

 the hind border, separating a narrow strip from the main portion of 

 the lobe. 



The dorsal surface of the pronotum is punctured as is the front 

 border of each lobe, while most of the central portion is smooth 

 and not punctured, although this varies according to the species. 

 There is a band of fine punctures along the upper border, while 

 the nan-ow strip behind the crenulate groove is closely and densely 

 punctured, as is the lov/er angle of each lobe. The epimera of the 

 prothorax are completely hidden by the pronotal lobes, and they are 

 separated from the proepisternum of each side by a sharp ridge which 

 lies against and fits closely to the marginal ridges of the pronotal 

 lobes. The episterna are elongate narrow lobes, apparently united 



