British Dragoiiflies. 



'(Fig. 13). At the tip of the mask are two movable 

 joints furnished with hooks, with \\hich the nymph 

 holds its prey. These hooks are no doubt the labial 

 palpi, and from their appearance the term forceps has 

 sometimes been applied to them (Fig. 14). 



Fig. 14. — Forceps ( = Labial palpi) at Tip of Mask of Anax 



impf.rator. 



(Much magnified.) 



P^'om Fig. 15 it may be seen how the mask varies in 

 shape, especial h' in the anterior jjart, in the different 

 sub-families. The way in which this interesting organ 

 is employed is sufficientl)^ striking. When a tiny red 

 worm or other apparently dainty morsel is sighted, the 

 nymph stcalthil)- creeps along, step by stej), so as not 

 to excite the attention of its prospcctixe prey. Arri\ed 

 within measurable distance, which, judging from its 



