5> 



C. ORTHOCLADIUS (LYONET AND MIALL). 

 LARVA: length io-u mm.; pale green; anal sense organs, 6 setas ; well developed 



tracheae ; epithelium with purple colouration. 

 LARVAL DWELLING : a free jelly-like case among filaments of Spirogyra, on which it 



feeds. 

 PUPA: respiratory cones tapering and spinous ; second abdominal segment with dorsal 



spinous prominence ; tail plates with roo minute setae to each. 

 HABITAT : ditches and streams. 



C. MINUTUS. 



LARVA : length 7 mm., pale green ; prothoracic claws toothed ; well developed tracheae. 

 LARVAL DWELLING : irregular gelatinous tube fixed to a stone, covered with particles. 

 PUPA : respiratory trumpets minute ; no tail fin. 

 PUPAL DWELLING : structureless transparent gelatinous case with spout-like aperture at 



each end. 

 HABITAT : streams. 



LAUTERBORN'S CHIRONOMUS 1. 

 LARVA : length 3-4 mm. ; reddish yellow ; prominent dorsal boss on segment 1 1 ; from 



segment 10 lateral pipe-like processes, hooked. 

 LARVAL DWELLING : like a spectacle case, compressed, opening by a slit at each end, 



brown, opaque, free, resembling Agraylia paUidula (Trichoptera). 

 HABITAT : meadow bogs and alder marshes. 



LAUTERBORN'S CHIRONOMUS 2 (REAUMUR). 

 LARVA: length 4-5 mm.; triangular boss on segment n dorsal; a pair of very long 



pipe-like ventral blood-gills on segment 10 (none on segment n). 

 LARVAL DWELLING : a spindle-shaped free case, translucent. 

 HABITAT : meadow bogs and alder marshes. 



CHIRONOMUS 10. 



LARVA : length 7 mm., green becoming yellow before pupating ; eight branched hairs 

 postero-laterally on segments 4-11; small I3th segment; tracheae complete, 



fine ; anal tracheal gills. 

 LARVAL DWELLING : fixed case composed of green leaves of Callilriche vcrna (Starwort). 



PUPA : small respiratory cones ; no tail-fin ; spinous projections on abdominal segments 



2-5- 

 PUPAL DWELLING : silken cocoon within larval case. 



HABITAT : ponds. 



CHIRONOMUS 11. 



LARVA : length 8 mm. ; pale green ; well developed I3th segment, with two pairs of 

 small bristles ; anal gills partly retractile ; fat-sacs present in segment 9 ; aorta 

 valved and contractile ; anal sense organs each five setae ; anal claws completely 

 retractile ; tracheae complete. 



