DIAPHORUS. 215 



Genus XII. DIAPHORUS. 



DiAPHORUS, Mg. zw. iv. 32 (1824); Mq. ; Ztt. DoUchopns p., Fin. ; 



Mg. 

 Antennce articiilo tertio j^atellcefornii, arista dorsali. Ocnli maris fronte 



contigui. Hypodoma latum. Vena prfebracJdalis simplex, transversa 



ab alee margins distans. Ilypopygium maris subimmersiim, subtus ap- 



pendicibus binis angustis defiexis. 



Antenna? short, with the first joint naked, the third joint broader than 

 long, rounded : the arista placed on its upper edge, long, slender, finely 

 pubescent. Eyes finely pubescent, meeting on the front in the male, 

 distant in the female. The face broad in both sexes, and rather short, 

 especially in the male, the antennfe being luore distant from the vertex 

 than usual. Occiput with a whitish beard behind the lower orbit. 

 Proboscis very short, projecting a little forwards. Wings like those 

 of Argyra, being broad about the anal angle, and the subcostal vein 

 longer than in other genera ; the pra^brachial vein simple as in most, 

 not forked as in Psilopus, and the subapical portion of it straight and 

 parallel with the cubital, the discal transverse vein distant by much 

 more than its own length from the hind margin. Tringe of the alulae 

 black. Abdomen conical in the female, in the male rather compressed 

 behind, with the sixth segment exserted, the small hypopygium partly 

 imbedded under the lip of it, armed behind with some spines, and 

 beneath with two slender, deflected, pubescent appendages, besides the 

 stouter forceps which is for the most part hidden in the ventral cavity. 

 The structure differing little from Argyra, and not much from Chry- 

 sotiis. The hind margins of the abdominal segments are a little ciliated 

 at the sides. Legs rather long and slender, the spines of the tibiae 

 few and slender, the fore pair with scarcely any, the femora much 

 more hairy in the male, the hind metatarsus unarmed, about as long as 

 the following joint. The males are at once known from every other 

 genus by the eyes meeting on the front ; the females may be more 

 easily confounded with other genera, but the form of the third joint of 

 the antennae and the insertion of the arista in connection with the length 

 of the subcostal vein will help to separate them. The colour is 

 usually dark. 



1. oculatus, Fin. dol. 28. 22(1823); ZiL—JIavocinctus, Mq. ; 

 Mg. — Fann. tuberculatus, Mg. JEneus, capite cinerascente, a)itennis pe- 

 dibusqiie nigris, alis suhfuscis, Jialteribus paUidis, femorum anteriorum 

 apice lato tibiisqne omnibus Jiavis ; Mas. abdomine in basi fascia pallida 

 subpeUucida. Long. 2 ; alar. 4 lin. 



Brassy. Head with a grejash covering. Mouth and antennae black. 

 Wings sliglilhj brown. Halteres pale. Legs black ; anterior femora 

 yellow towards tlie tips ; tibice yellow. Male. Hypostoma broad, veiy 

 short, whitish. Eyes bluish-violet, with brassy borders. Palpi small, 

 ferruginous. Abdomen with a yellow semipellucid baud on the second 



