DURHAM DIPTERA. 135 



XXIV. 219. 



219. Psilopus, Mg. 



1 (2). Antennae all black. (1183. Icetus, Mg.) 



2 (1). Antennas yellow, at most the third joint black. 



3 (4). Hind metatarsus at least twice as long as the next 



joint. Mid tarsi with the third and fourth joints 

 white in the male. 



1 180. Psilopus platypterus, F. 

 Bishop Auckland, 1 ?, 20-7-00 ; Hesleden, 2 $, 8 ?, 

 August, 1902. 



4 (3). Hind metatarsus only a little longer than the next joint. 

 6 (6). Fourth tarsal joint of fore legs much enlarged in the male. 



1 181. Psilopus wiedemanni, Fin.? 

 Hesleden, 1 ?, 18-8-02. 



6 (5). Fourth tarsal joint of the fore legs not enlarged. 



7 (8). Abdomen with inconspicuous bands. 



(1182. longulus, Fin.) 



8 (7). Abdomen with broad dark bands. 



(1184. contristans, W.) 



220. Neurigona, Rnd. 



1 (2). Thorax and abdomen yellow. (1185. pallida, Fin.) 



2 (1). Thorax grey, abdomen yellow with dark bands. 



3 (4). Wings distinctly darkened on the fore margin. V.4. 



almost parallel with V.3. (1186. suttiralis, Fin.) 



4 (3). Wings not darkened. V.4. distinctly converging 



towards V.3, Third and fourth fore tarsal joints 

 black plumed in the male. 

 1 187. Neurigona quadrifasciata, F. 

 Barnard Castle, 1 ?, 20-6-00. 



222. Hygroceleuthus, Lw. 



1 (2). Antennas much longer than the head. Legs all 



yellow, except the last tarsal joint. V.4, bent 

 obtusely. (1190. latipennis, Fin.) 



2 (1). Antennas only rather longer than the head. The 



legs yellow, the tip of the hind tibiae and all the 

 tarsi, except the fore metatarsi, black. V.4. twice 

 bent rectangularly (V. 14). (1189. diadema, Hal.) 



