153 CHIRONOMID.E. 



fleshy leg ou the under side of the first segment, whicli points 

 towards the head, and which it has the power of lengthening or 

 contracting. Its various serpentine contortions also assist it in 

 moving. AVhen removed from the substance wliich constitutes its 

 food, it is enabled to regain it by leaping. Lying horizontally, it 

 brings the anus near the head, regulating the distance by the 

 length of the leap it means to take ; when, fixing it firmly, and 

 then suddenly resuming a rectilinear position, it is carried through 

 the air sometimes to the distance of two or three inches. It appears 

 to have the power of flattening the anal extremity, and even of 

 rendering it concave, by means of which it may probably act as a 

 sucker, and so be more firmly fixable." 



This genus may be divided into four principal groups : — 



* Prcebrachial areolet open. 



t Wings deflected. Auteunae of the male with thirteen joints, of 

 the female with seven joints. 

 X Autennse of the male feathered. Group 1. 

 XX AntennfE of the male with few hairs. Group 2. 

 ff Wings incumbent. Antennae of the male twelve-jointed, fea- 

 thered; of the female seven-jointed. Group 3. 

 ** Pj'sebrachial areolet closed externally. Group 4. 



The species of the first group may be arranged in the following 

 sections : — 



A. Fore metatarsus longer than the fore tibia. 



a. Fore metatarsus twice the length of the fore metatibia. 

 b. Wings not spotted. 



c. Thorax black or grey. Species 1, 3. 

 c c. Thorax green, with three black stripes. Species 3-5. 

 c c c. Thorax green, with three testaceous stripes. Species 6-9. 

 c c c c. Thorax testaceous or green, not striped. Species 10, 11. 

 l b. Wings spotted. Species 13. 

 a a. Fore metatarsus longer than the fore tibia by three-fourths. 

 b. Thorax black. Species 13-15. 



b b. Thorax green, with three black or brown stripes. Speciesl6-30. 

 b b b. Thorax green, with three testaceous stripes. Species 31-34. 

 a a a. Fore metatarsus longer tlian the fore tibia by two-thirds. 

 b. Wings not spotted. 



c. Thorax black, or grey. Species 35, 36. 



c c. Thorax pale, with three black or brown stripes. Species 



37-33. 

 c c c. Thorax pale, with three lutcous stripes. 

 d. Al)doinen witli black bands. Species 33. 

 d d. Abdomen witliout bands. Species 34-40. 

 c c c c. Thorax not striped. Species 41, 43. 



