116 
Psyche 
[December 
stripes which may be more or less confluent; palpi 
dark 6 
6. First tarsal joint of fore leg about % as long as the 
tibia: cornuta 
First tarsal joint of fore leg about % as long as the 
tibia 7 
7. Apical segment of the clasper of the male fully as broad 
beyond the middle as at the base; Sc ends about 
opposite the base of Rs ; distance between the cross- 
veins measured on the media usually not exceeding V 2 
the length of the m-cu crossvein : modesta 
Apical segment of the clasper of the male tapering ; Sc 
ends distinctly proximad of the base of Rs ; distance 
between the crossveins about equal to the length of 
the m-cu crossvein : similis 
Larvse 
Only two of the species given in the key above are known 
in the larval stage, D. modesta Joh. and D. cornuta (Joh.) 
which may be separated by using the key by Johannsen 
(1934). 
Subfamily Chaoborinae 
Key to Genera 
Adults 
1. Clypeus small and nearly bare ; R 1 ending far from tip of 
R 2 : Corethrella 
Clypeus larger and very hairy; R x ending close to tip 
of R 2 2 
2. First tarsal segment much shorter than second: 
Mochlonyx 
First tarsal segment longer than second 3 
3. Clypeus as long as head ; claws larger and toothed : __ 
Eucorethra 
Clypeus shorter than head ; claws small and simple : 
Chaohorus 
Larvx 
1. Eighth abdominal segment with an elongate single dor- 
sal respiratory siphon or air tube 2 
