410 ME. P. W. EDWAEDS ON DIPTEEA 



Genus Dissoptera *, gen. nov. 



Eyes bare, widely separated in both sexes. Face slightly produced, without any 

 trace of a central knob. Antennae of normal form ; third joint subcircular, arista 

 bare. Thorax with a peculiar vestiture, described below. Abdomen somewhat 

 conical. Legs rather slender, hind-femora quite simple. Wings bare ; marginal cell 

 closed ; dip in the third vein distinct, but not very deep ; small cross-vein placed very 

 much before the middle of the discal cell ; subapical cross-vein normal. 



Perhaps allied to the South European PalumMa, but differing from that genus in 

 having the eyes of the male widely separated, and from all other members of the 

 subfamily in the position of the small cross-vein. In this latter respect the insect 

 seems to approach the Volucellinse, but it is not likely that it is a genuine connecting 

 form, since the whole habitus is that of an JEristalis. 



45. Dissoptera pollinosa, sp. n. (PI. XXXVIII. fig. 6.) 



1 S . Iwaka River, February 1911 {A. F. R. Wollaston). {Type of the species.) 

 1 c? . From Dong Hanon, Mishmi Country, 2000 ft., on the Tibetan frontier of 

 N.E. India, 27. vii. 1911 {F. M. Bailey). 1 ? . Mt. Dulit, North Borneo (A. H. Everett). 

 1 ? . Aneiteum, New Hebrides. 1 ? . New Hebrides [Saunders coll.) ; all in the 

 British Museum. 



Head : eyes absolutely bare, a trifle more widely separated in the male than in the 

 female. Vertex velvety black, with some short black hair. Frons blackish, the sides 

 somewhat convergent above, bare in the middle line above the antennae, clothed at 

 the sides with very small yellow scales ; towards the middle these scales are less dense, 

 and instead of being flattened are solid, appearing under a hand-lens like grains of 

 pollen ; mixed up with these peculiar scales is a considerable amount of black hair, 

 which is as long as the two basal joints of the antennae. Face somevs^hat shining 

 black, bare in the middle, thickly clothed at the sides with yellow hair or hair-like 

 scales ; very slightly produced at the oral margin ; no trace of a central knob. 

 Antennae dark brown, the third joint reddish except on the front-margin; arista bare, 

 slightly thickened towards the base. Thorax : mesonotum and scutellum clothed with 

 a mixture of minute, solid, yellow " scales " and comparatively long black hair, just as 

 on the frons ; the yellow " scales " are densest on the scutellum ; hair on margins of 

 mesonotum yellow ; pleurae with large tufts of long yellow hair. Abdomen: blackish 

 brown ; second segment with a pair of large sub-triangular orange-yellow spots at the 

 sides towards the base; third and fourth segments with similar but smaller and 

 differently shaped spots. Pubescence mainly yellow, but mixed with black on the 

 dark portions. In the specimens from the New Hebrides the abdomen bears scales 



* Siaaos, ambiguous. 



