'36 Transactions. — Zoology. 



Family SYKPHID^E. 



" Three basal cells much prolonged ; third longitudinal 

 vein simple ; a spurious longitudinal vein between the third 

 and fourth. Fourth longitudinal united at its end with the 

 third ; no intercalary veins. Hypopygium unsymmetrical. 

 No empodium " (Loew). 



The third basal cell is closed, and there are three posterior 



•cells, of which the first and second are closed and the third 



is open. In Melanostoma decessa the spurious longitudinal 



vein is absent. 



Key to the Genera. 



Abdomen broad ; submarginal cell dilated. 



Marginal cell closed . . . . - . . . Eristalis. 



Marginal cell open .. .. .. .. Eelophilus. 



Abdomen slender ; submarginal cell not dilated. 



Anterior basal cell attaining to more than half the 



discal . . . . . . • . • • Milesia. 



Anterior bas-al cell attaining to less than half the 

 discal. 

 Scutellum pale .. .. .. •• Syrphus. 



Scutellum dark .. .. .. .. Melanostoma. 



Genus Eeistalis, Latreille (1802). 



Antennae approximated, seated on a tubercle ; arista ai 

 the base of the third joint. First and second longitudinal 

 veins meeting before the margin of the wing. Halteres 

 covered by the squamae. Eyes contiguous in the male. 



Eristalis tenax. 



Musca tenax, Linn., Syt. Nat., ii., 984. Eristalis tenax, 



Hudson, Trans. N.Z. Inst., vol. xxii., p. 187. 



Piceous, with tawny hairs. Abdomen with a large tawny 

 spot on each side, which is much larger in the male than in 

 the female. Hind borders of the segments tawny. Length. 

 $ 13 mm., ? 15 mm.; wing, $ 11mm., ? 12 mm. 



Hab. Throughout New Zealand. Very abundant. 



Introduced, probably from England. First noticed in 

 Wellington in the spring of 1888, by Mr. G. V. Hudson. 

 Mr. W. W. Smith took two specimens at Ashburton in 

 November of the same year, and by 1890 it had become 

 common. 



Genus Helophilus, Meigen (1822). 



Body broad. Eyes separated in both sexes. Face pro- 

 minent. Antennae inserted on a projection in front ; the 

 third joint almost circular ; the style inserted near its base. 

 Thorax hairy. Abdomen partly hairy or entirely naked. 

 Legs hairy; the posterior femora thickened, the tibiae in- 

 curved, produced into a tooth at the apex on the inner side. 



