PSILOPUS. 151 



Pale metallic green, somewhat shining. Front and face glossy 

 white. Face long and narrow, in the male very narrow. Wings 

 broad, in the male very broad, rounded and divaricated. Abdomen 

 with dusky incisures. Hypopygium of the male with a pair of hairy 

 oblong valves shorter than itself, the other appendages very minute. 

 Legs pale yellow, only the tips of the tarsi darker. In the male the 

 fore femora are fringed beneath with fine soft hairs, particularly towards 

 tJie tip, the third and fourth joints of the fore tarsi are each longer than 

 the second, the fifth very short ; the middle tarsi have the third and 

 fourth joints compressed, white, the fifth with the tip of the fourth 

 black. TJie first joint of the hind tarsi is twice as long as the second, 

 scarcely so much in the female. 



The most abundant species in these islands ; fond of resting 

 on the shady side of gates and palings, in small troops, chasing 

 each other about very playfully. 



2. Wiedemannii, Fin. d. s. dol. 24. 2 (1823); Ztt. Pallide 

 ceneo-viridis, capite albido, pedibm pallidis, tarsis fuscis ; Mas. tarsorum 

 anticorum articulo quarto lobato, femoribus anticis subtiliter pilosis. 

 Long. 2-3 ; alar. 5 lin. 



Pale metallic green, somewhat shining. Face glossy white, rather 

 broad, front yellowish-white. Abdomen with dusky incisures, the 

 transparent pale colour of the belly sometimes extending to the sides in 

 spots. Hypopygium of the male with four appendages that end nearly 

 at the same length, the uppermost ("aculeus," Zlr.) very slender, 

 springing almost from the base, then a pair of incurved ones forming 

 the forceps, the undermost one compressed and dilated towards the 

 base ; under this last again a shorter obtuse one, with some longer 

 hairs at the tip of it, as well as of the forceps. Legs pale yellow ; tarsi 

 dusky, except at the base ; the first joint of the hind pair scarcely 

 longer than the second. The male has the tip of the fourth joint in tlie 

 fore pair compressed, and produced in a lobe over the fifth, and black 

 like it, and there are a few long fine hairs on the underside of the fore 

 femora towards the base. The female is usually more yellowish-green, 

 sometimes almost ochre, with little of metallic tinge. 



Not uncommon on some tracts of sandhills close by the sea. 

 (E. S. I.) 



Obs. P. nervosus, Lhm. (Nov. Act. Acad. dec. 2. xii. 242), 

 as synonymous with which Meigen cites P. Wiedemannii, Fin., 

 erroneously, is distinguished by the strongly bent discal trans- 

 verse vein, and the longer first joint of the hind tarsi : the male 

 has a tuft of five long hairs at the base of the fore femora, the 

 first of them longer than the thigh, and the hypopygium furnished 

 with a pair of very long hairy appendages. This species has 

 been introduced into British lists, probably by error for P. 

 Wiedemannii. 



