DIODONTUS LUPERUS. 171 



cately punctured ; the clypeus tridentate ; the mandibles yellow, 

 their apex ferruginous. Thorax delicately punctured on the 

 disk; the metathorax rugose, the base rugose-striate ; the 

 tubercles and tegulse in front yellowish white, the latter rufo- 

 testaceous behind ; the wings hyaline and splendidly iridescent, 

 the nervures rufo-testaceous ; the anterior and intermediate 

 tibiae, and the posterior at the base and apex, the tips of the 

 femora and the tarsi, fulvous ; the anterior tibia? sometimes 

 yellowish and with a fuscous stain outside, sometimes the pos- 

 terior tarsi fuscous. Abdomen with a slight griseous pile. 



Male. — Rather smaller than the female, and with the face covered 

 with silvery pubescence ; the flagellum yellow beneath, with 

 the tips of the joints fuscous ; the basal joint of the anterior 

 tarsi curved ; the legs paler than in the other sex ; the basal 

 joint of the intermediate tarsi dilated at its apex behind. 



Some of the males of this abundant species have the head very 

 large, sometimes twice as wide as the thorax. Taken in great 

 numbers entering its burrows in a bank which it was provision- 

 ing with a species of Aphis. 



2. Diodontus luperus. 



D. ater ; incisura inter mesothoracem et scutellum simplice. 



Diodontus luperus, Shuck. Foss. Hym. 186. 2. 

 Dahlb. Hym. Europ. i. 254. 153. 



Female. Length 1\ lines.— Black and shining ; the head finely 

 ^punctured, the face most closely and strongly so; mandibles 

 entirely black, or sometimes slightly ferruginous at their apex. 

 Thorax : the disk with a few scattered fine punctures ; the 

 incisure which separates the scutellum from the mesothorax 

 simple, not crenate or punctured; the metathorax rugose, 

 rugose-striate at the base; the wings hyaline and splendidly 

 iridescent ; the anterior tibiae yellowish in front, the basal joints 

 of all the tarsi more or less rufous, the intermediate and poste- 

 rior tibiae spinose, the anterior tarsi ciliated. Abdomen very 

 slightly pubescent, the apical margins of the two or three ter- 

 minal segments sometimes rufo-piceous. 



Male rather smaller than the female, with face silvery; the 

 anterior tibiae and tarsi, and the base of the posterior tibiae, 

 yellow; the anterior tibiae have sometimes a dark stain behind. 



Equally abundant as the preceding species, and readily distin- 

 guished by the colour of the mandibles, and the simple'incisure 

 at the base of the scutellum. 



i2 



