THE DIPTERA. 43 



gerris * ; it may be at once distinguished by its dark 

 colour. 



Family TiPULlDyE. 



Corethra antarctica, n.s. 2 (Plate IV., fig. 3, 3a larva, 

 3b pupa). 



An elegant little gnat, frequenting the margins of ponds 

 and ditches during the spring months. The larva (Fig. 

 3a) is bright green, ornamented with numerous yellow 

 spots ; it is very sluggish, living in the green slime weed 

 which floats on the water in such large masses during that 

 season. Not being very common it is difficult to find, 

 as its colour so closely resembles that of the weed which 

 it always frequents. The pupa (Fig 3b), is not very 

 agile, and is nearly always observed suspended from the 

 surface by its thoracic air-tubes and caudal fins, the ab- 

 domen being directed upwards and thus bringing the two 

 pairs of organs close together. In its metamorphosis and 

 general appearance this insect forms a convenient link 

 between the present family and the Culicidae. 



Family 



Chironomus zealandicus, n.s. (Plate IV., fig. 2, 2a larva, 



2b pupa). 



This is the common midge of New Zealand, and is 

 extremely abundant throughout the country. Its larva 

 (Fig. 2a) inhabits the soft mud at the bottom of stagnant 

 ponds and streams, and is very conspicuous, being of a 

 brilliant crimson colour and thus much resembling the 

 well-known " Bloodworm " of English anglers, which is 

 the larva of a closely allied European species (C. plumosus). 

 It may be readily kept in an aquarium, and if supplied 

 with a little soil and green weed will rapidly cover the 



1 A genus of Hemipterous insects commonly seen skipping over 

 ponds in England. 



2 "n.s." is the accepted abbreviation for new species." 



