DURHAM DIPTERA. 355 



XLIX. 605. 



5 (2). Pleural spot small; wings without clear spots. 



(humeralis, Beck.) 



6 (1). Pleurae without any velvet-black spot, (nitida, Mcq.) 



607. Pelina, Hal. 



1 (2). Dorsum punctate, matt. (2625. cenea, Hal.) 



2 (1). Dorsum shining. (2626. cenescens, Stnh.) 



609. Canace, Hal. 



1 (2). The four dorso-central and other bristles strongly 



developed. (2628. nasica, Hal.) 



2 (1). Thoracic bristles weakly developed. 



(2629. ranula, Lw.) 



610. Parhydra, Stnh. 



1 (12). Bare species. 



2 (7). V.2. with a hang-vein near its end. 



3 (4). The hang-vein not brown clouded. 



(2635. c oar data, Fin.) 



4 (3). The hang-vein brown clouded. 



5 (6). V.2. from the hang-vein bent gradually up ; C 2 nearly 



double as long as C 3 ; frontal triangle rounded in 

 front. 



2633. Parhydra quadripunctata, Mg. 

 Howick, 1 ?, 22-8-05. 



6 (5). V.2. suddenly and sharply angled upwards ; C 2 at 



most half as long as C 3 ; frontal triangle deeply 

 incised, trifoliate. (2636. litoralis, Mg.) 



7 (2). V.2. without a hang-vein. 



8 (9). C 2 at least twice as long as C 3 ; large species, 3^-4^ mm. 



2634. Parhydra aquila, Fin. 

 Hesleden, 3 ?, August, 1899. 



9 (8). C 2 but little longer than C 3 ; smaller species, 1-2J mm. 



10 (11). Besides the usual facial bristle, another nearly as long 



beneath it. (2630. pusilla, Mg.) 



11 (10). No second facial bristle, only a few small hairs. 



(2632. fossarum, Hal.) 



12 (1). Very hairy species. (2631. pubera, Lw.) 



