428 BRITISH OBIBATID.^. 



Nymph. 



When the larva becomes a nymph not only does the 

 fourth pair of legs appear but the different papillfB 

 become less conspicuous ; and this process continues as 

 the nymph grows older, until the mature nymph hardly 

 shows any papillee except those at the hind margin, 

 the hairs seeming to spring almost from the surface of 

 the notogaster. The creature moreover loses its clean 

 appearance with age, all sorts of debris are piled upon 

 the back and adhere to the long hairs in a permanent 

 manner, until, although not plastered with mud like the 

 nymph of D. geniculatus, it is almost as much covered ; 

 amongst the debris which it picks up will frequently 

 be found its own eggs or those of other creatures. 

 The colour is a little darker than that of the larva, 

 and the rostrum somewhat more chitinised ; the hairs, 

 which are still very long, do not seem so long in pro- 

 portion to the body. In other respects the larva 

 resembles the nymph. 



Distribution. — Common and generally distributed, 

 chiefly found in moss. It has been recorded in Switz- 

 erland, Germany, France, Italy, &c. 



Dam^us geniculatus {Linn.). PI. XXXIX; PI. D, figs. 



8, 9, 10, 17; PI. E, 

 figs. 4, 12, 17 ; PL F, 

 figs. 1, 6, 7, 10 ; PI. 

 Gr, figs. 1, 5. 



Tyjpe species. 



Acarus geniculatus, Linn. System, natur., 12tli ed., vol. ii, 



p. 1025, No. 19. 



— — — Fauna Suec, 2nd ed., No. 1977. 



— — Fabricius. Entomol. System., vol. iv, p. 431, 



No. 32. 



