DURHAM DIPTERA. 63 



IX. 93. 



8 (9). Abdomen dark brown with distinct white bands. 



(646. cantans, Mg.) 



9 (8). Abdomen pale brown or orange. Bands absent or 



very faint. (648. annulipes, Mg.) 



10 (1). Tarsi without white rings. 



11 (12). Small species less than 4 mm., with white side dots on 



the abdomen. (652. lateralis, Mg.) 



12 (11). Larger species, at least 5 mm. 



13 (18). Femora mostly pale, only dark at the point. 



14 (15). Femora with a shimmering silver spot at the point. 



655. Culex nemorosus, Mg. 

 Bishop Auckland, 2 $, July, 1900-02. 



15 (14). Legs without the silver spot. 



16 (17). Large brown species, 6 mm., with dark abdomen. 



659. Culex pipiens, L. 

 Very common. 



17 (16). Smaller reddish species, 5 mm., with light brown 



abdomen. 



659. Culex ciliaris, L. (var. of pipiens?) 

 Not uncommon. 



18 (13). Femora mostly black. 



19 (20). Pleurae with a tuft of shining silver hair. Thorax 



thickly pale-haired with two dark stripes. 



(653. ornatus, Mg.) 



20 (19). Pleurae without silver tuft. Thorax unstriped. 



21 (22). Thorax with reddish hairs. Abdomen plain brown- 



black. (658. nigrituhes, Ztt.) 



22 (21). Thorax all black haired. Abdomen black in the 



male, white ringed in the female ; legs all dark. 



(656. nigripes, Ztt.) 



Family X.— DIXID^E. 

 95. Dixa, Mg. 

 The larvae live in water. 

 1 (4). Wings spotted, at least with the X-veins clouded. 



