152 DURHAM DIPTERA. 



XXIV. 2S7h 



2 (3). Tip of the wing with a conspicuous black spot. 



{scholtzii, Lw.) 



3 (2). Tip of the wing uncoloured. {adpropinquans, Lw.) 



4 (1). V.3. and V.4. almost parallel. {bifiartitus, Lw.) 



238. Syntornum, Lw. 



1 (10). Last two or three joints of the mid tarsi not dilated. . 



2 (3). Fore and mid femora with three bristles beneath near 



the base ; squamae with dark fringes ; hind meta- 

 tarsi unarmed (without spines or processes) 

 beneath. (1302. pumilus, Mg.) 



3 (2). Fore and mid femora without bristles beneath ; 



squamae pale haired. 



4 (5). Hind tibiae not ciliated nor dilated towards the tip ; 



mid femora with about twelve minute bristles 



beneath ; hind metatarsus with two small curved 



spines near the base. (denticulatus, Ztt.) 



(Dark brown legs=var. dentiadatus, Ztt. ; yellow 



legs=var. biseriatus, Lw.). 



5 (4). Hind tibiae distinctly ciliated or dilated towards the 



tip, or if ciliation indistinct then mid femora with- 

 out the minute bristles beneath. 



6 (7). Femora mostly black; fore metatarsi with a short 



blunt prolongation at the tip ; hind metatarsi with 

 a hooked tooth at the base beneath and two leafy- 

 appendages. (1300- zelleri, Lw.) 



7 (6). Femora all yellow except hind tip ; fore metatarsi 



simple. 



8 (9). Hind metatarsi at the base beneath, with a hooked 



tooth divided at the tip ; hind tibiae scarcely 

 dilated ; abdomen often yellow at base. 

 1306. Syntornum pallipes, F. 

 Hesleden, Brancepeth, June-August, 1901-02. 



9 (8). Hind metatarsi with two long bristly hairs beneath ; 



hind tibiae blackened, dilated, flattened, and 

 channelled. (1304. sulcipes, Mg.) 



