DURHAM DIPTERA. 1 69 



XXVIIL 

 87 (36). Abdomen not flat nor clubbed, and usually with pale 

 or yellow spots or bands. Wings not shorter than 

 the abdomen. 



38 (39). Front tibia or tarsi of the male dilated (VII. 6-10), 



of the female short and broad. Abdominal spots 

 in female quadrate (VII. n). 



Platychirus, St. Farg. (279) 



39 (38). Front tibiae and tarsi simple in both sexes. 



40 (43). Abdomen narrow with parallel sides. 



41 (42). Eyes slightly hairy ; female without yellow markings. 



282. Melangyna, Verr. (1500. quadrimacu 'lata, V err.) 



42 (41). Eyes quite bare ; female with yellow triangular marks 



(VII. 12), or steel-blue cross bands. 



Melanostoma, Schin. (281) 



43 (40). Abdomen broad, flat, ovate. 



283. Xanthandrus, Verr. (1501. comtus, Harr.) 



44 (35). Face partly yellow. 



45 (48). Eyes separate in both sexes ; third antennal joint 



very large ; arista thick and almost terminal. 



46 (47). Third antennal joint with pointed upper fore corner. 



293. Pelecocera, Mg. (1554. tricincta, Mg.) 



47 (46). Third antennal joint with rounded upper fore corner. 



294. Chamjesyrphus, Mik. (1555. sccevoides, Fin.) 



48 (45). Male eyes touching. Antennae normal. 



49 (52). Thorax with yellow side lines. Pleurae yellow 



marked. 



50 (51) Broad flat species. Xanthogramma, Schin. (290) 



51 (50). Narrow elongate species. 



Spieerophoria, St. Farg. (289) 



52 (49). Thorax without conspicuous side lines. Pleurae un- 



spotted. 

 63 (56). Abdomen with a broad transparent whitish basal 



band, sometimes divided in the middle. 

 54 (65). Wings with a dark middle band. 



Leucozona, Schin. (284) 

 65 (54). Wings without a band. Ischyrosyrphus, Big. (285) 

 56 (53). Abdomen without the broad basal band. 



