274 British Dragonflics. 



mid-dorsal black stripe. This form of the female is 

 usually not at all uncommon in some localities. A 

 specimen of this species taken in Richmond Park had 

 two small distal blue spots on dorsal surface of seventh 

 segment of abdomen. 



Nymph. 



Mr. W. H. Nunney thus describes the nymph of 

 IscJimira clegaiis in "Science Gossip," September, 1894: 

 " /. clcgaus usually greenish-yellow, varies greatly in 

 colour, that of the head and eyes changing according to 

 the creature's age. Two fascia.^ occur around the basal 

 tubercles of the antennae ; two curved lines converge 

 towards the tubercles of the ocelli, and two other 

 curved lines occur on the hind-borders of the head, 

 tending medially towards the other lines, from which 

 they are divided by a small straight line crosswise in 

 the centre of the curved hinder margin ; on the fore- 

 face are two slight depressions, usually filled with dirt 

 particles, consequently difficult to see. The body has 

 on all but the final segments four curved lines arranged 

 thus, )()(. Peculiar spines occur on the metacarpus ; to 

 see these a microscope is necessary. The cauda; are 

 ovoid, spined along the basal upper margins, and are 

 slightly notched where the spines end. The central 

 tracheal stem is thickened, and is crossed at the 

 marginal notch by an additional thickening. According 

 to Roster, the apical angles alter with the age of the 

 nymph." Mr. R. M. Whattson sa}'s that the lamelhe 

 are pointed. In an cm|)ty nymph-casc which I believe 

 to belong to this species, the dark branchlets of the 

 somewhat narrow lamella (two are lost) are very numerous. 



