XX INSECTA : NEUROPTERA 305 



Genus 3. Orthetrum. — Wings clear and unstained, the abdomen 

 may be narrower than in Libellula or as broad. The 

 abdomen in the male is blue, in the female brown. 



Sub-family 2 : Aeschnidae. 

 The Dragon-flies of the sub-family Aeschnidae are large 

 forms in which, as in the Libellulidae, the eyes meet on the 

 head for some distance ; but the three ocelli are in a straight 

 line on the front of the head, and the abdomen is very long 

 and narrow. The larva also is larger, with a relatively 

 longer abdomen and stronger legs than in a Libellula larva. 

 Genus 1. Aeschna. — The base of the inner margin of the hind 

 wing on the male is characterised by having a sharp 

 point. The male is usually brown, spotted with blue, 

 though it is nearly all brown in the common A. grandis. 

 „ 2. Anax. — Large, beautifully bright 



forms, the body of the males » 



blue, and of the females green, j^^^f 



with a long irregular black line b — 'JjlS^^S 



down the back of the abdomen. -jfw\U 



„ 3. Cordulegaster. — The name is ^^W W 



derived from the Greek cordule r/lm' 3 

 = a club, so called from the ^f B i 

 shape of the abdomen, which is / /Kb' 

 thin in the centre, and thicker fl jfW ^^ 



at both ends. The body is Mr 



greenish black, with transverse Ul 



yellow markings. yBj 



Sub-family 3 : Agrionidae. _ — t^ W-.^ ==- ^^= 



The members of this sub-family are ^^:^~^^^E^^te- 



relatively small forms, and the eyes are "3:^^C^^^^^S 



wide apart and large. The abdomen is J^^s^ ^^;=^^ ^ 



slender and usually brightly coloured, ^~--Hr° " 



the wings very narrow, transparent, and Pio. 228. 



uucoloured, except for the small dark One of Agrionidae. 



patch or stigma present on the front of «> Empty nymph skin ; b, 



each wing in both sexes. There are ™^<'^»'i="«'^emsrged 



o ... from a; n, node of wing. 



only two small cross veins in the space 



between the node of the wing and its base. The larva is a 



slender, greenish-coloured little creature, with three delicate 



VOL. I X 



