Descriptive Features: head wider than deep, frons rounded
labium just showing from beneath head as viewed dorsally, setae absent
antennae very long, 5-segmented, scape short, pedicel nearly 4X longer, segment 3 1/3 length of pedicel, other segments progressively shorter, segments 3- 5 black except at apices
vertex marbled with brownish grey, ocelli outlined in this colour; occiput shallowly concave, bulging and globular behind eyes where it is finely spined
labial mask kite-shaped, deep black in colour except the lobes
lateral lobes with a long robust movable hook and terminating in 2 stout teeth, the innermost the longer and acuminate at apex
medial lobe projecting as 2 rounded lobes separated by a deep but closed fissure, the free border finely dentate
prothorax oval, marked with a parallel pair of short longitudinal middorsal stripes of black, as well as its sides
thorax bulky, blackish except on middorsum and medial borders
legs rather long and slender, ridged but without armature save some bordering minute spines
coxae, base and apex of femora as well as 2 medial rings black, tibiae with 2 black rings
abdomen cylindrical, tapering, pale on dorsum and blackish beneath and with a narrow blackish band extending along each side from end to end
caudal gills broadly oval, rather obtusely pointed at apices, median gill hardly shorter than lateral gills, all gills black except a conspicuously pale yellowish apex, held vertically and closely
Total length: 17 mm |
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Chorismagrion risi |
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