The Life-history of an Aearus, dtc. Bij A. D. Michael 383 



moreover, provided with a remarkable hooked holding claw on the 

 front leg, which resembles those found on Pecliculus, Fygme- 

 phorus, and other creatures living more or less parasitic lives on 

 hairy animals. Neither the male nor the immature stages of this 

 Acarus have, to my knowledge, been found on the bee. At the 

 end of that paper I ventured to suggest that there were many 

 undescribed species belonging to the same genus ; the present 

 species is one of these. 1 have not, however, found the adult 

 females in any parasitic or semi-parasitic condition. All the 

 specimens of that sex which I have found have been free-Hving 

 creatures, inhabiting moss from old wood, &c. The adult male 

 and the larva I have not ever found at all ; the way in which 

 I obtained them was as follows : — In the spring of 1885 I 

 obtained some adult females of the species at the New Forest. 

 I did not obtain them there for the first time ; I knew the species 

 well before, but I took advantage of having a good many healthy 

 specimens to endeavour to trace the life-history ; I concluded 

 that they were adult females, from their resemblance to those 

 of D. homhi. I had traced the history of that species by confining 

 the adult females in a cell, the bottom of which was covered with 

 damp blotting-paper, and into which I placed a small piece of 

 cheese. I tried the same plan with the present species, but the 

 Acari did not seem to take kindly to the cheese. I then took out 

 the cheese, leaving the blotting-paper, which had become smeared 

 with cheese, and was kept damp ; in this way a fungoid growth 

 was promoted, upon which the creatures throve well : they now 

 laid eggs, and I was able to breed the larvae from these eggs, and 

 the adult male and female from the larvae. I have not ever obtained 

 the larva or the adult male any other way. In this species, as in 

 D. homhi, there is not any nymphal stage; the change from 

 hexapod larva to imago being direct, without the intermediate, 

 immature, octopod stage usual in the Acarina. 



Although the female is, as far as I know, a free-living creature, 

 yet its hypopial appearance suggests that it may probably use other 

 animals as a means of conveyance ; but on the other hand, the 

 front leg is without the great claw adapted to hold hairs ; the claw 

 is almost abortive on that leg, which has become a tactile organ. 

 I have utilized this absence of the hook for the name which I pro- 

 pose for it, viz. Bisparipes exhamulatus* The absence of this 

 hooked claw may of course mean that during its parasitic period 

 its host is hairless ; but when taken in conjunction with the fact 

 that I have not hitherto found it parasitic on anything, and that I 

 do find it in a non-parasitic condition, it may not improbably 

 indicate that the creature, although descended from a species like 



* Exhamulatus, deprived of a hook (hamula, a little hook). 



