OXYBELUS MUCRONATUS. 163 



former usually yellowish-white ; the anterior tarsi ciliated, and 

 the intermediate and posterior tibiae spinose. Abdomen shining 

 and delicately punctured, the margins of the segments slightly 

 constricted; a large ovate macula on each side of the basal 

 segment, the second, third and fourth with a transverse line on 

 each side, the latter sometimes united, yellowish-white, the 

 fifth segment with a continuous band ; the markings frequently 

 more or less obliterated, those on the three basal segments 

 usually present. 



Male. Usually rather smaller, the face more silvery, the legs 

 with more yellow at the base of the tibia?, the latter being fre- 

 quently dashed with yellow outside, the posterior pair having 

 usually a large black splash outside ; the abdomen with only 

 the two basal segments maculated with white, in very rare 

 instances entirely black. 



A most abundant insect, occurring in most sandy situations ; 

 very highly-coloured examples are sometimes found at Deal, 

 Dover, and Lowestoft, where it is extremely numerous. 



2. Oxybelus mucronatus. 



0. niger, argenteo-sericeus ; thorace abdomineque flavo-macu- 

 latis ; pedibus testaceis ; mucrone metathoracis acuto. 



Crabro mucronatus, Fabr. Ent. Syst. ii. 300. 25 <j> . 

 Oxybelus mucronatus, Fabr. Syst. Piez. 318. 5. 



Latr. Gen. Crust, et Ins. iv. 79. 



Dahlb. Hym.Eur. i. 266. 162. 



Wesm. Hym. Foss. Belg. 157. 2. 

 Oxybelus ferox, Shuck. Foss. Hym. 108. 2 <J . 

 Oxybelus argentatus, Curtis, Brit. Ent. x. 480 $ 



Shuck. Foss. Hym. 111. 5. 



Female. Length 4 lines. Black, covered with dense glittering 

 silvery pubescence ; the apex of the scape, and one or two of 

 the apical joints of the flagellum, fulvous. Thorax : the tu- 

 bercles arid tegulae in front yellowish-white ; a transverse yellow 

 plate, dentate at its lateral posterior angles, at the apex of the 

 scutellum ; the mucro at the base of the metathorax grooved 

 above and acute at its apex ; the metathorax reticulated ; the 

 wings hyaline and iridescent, the nervures pale rufo-testaceous ; 

 the legs pale rufo-testaceous, with the anterior femora, the 

 intermediate and posterior pairs at their base, and the tro- 

 chanters and coxae dark reddish-brown, sometimes nearly 

 black ; the anterior tibiae in front, their femora at their apex, 



