A Species of Acariis new to Britain, By A. D. Michael, 317 
from the outer side, is sharply bent round almost immediately, so as 
nearly to continue the line of the leg. 
The nymph is octopod, very like the perfect acarid, but smaller 
and shorter ; it has the red colour of the adult. 
Since the above paper was read I have succeeded in finding the 
male. I continued breeding the creature in hopes of obtaining it, 
hut without result, until nearly the end of August, when suddenly 
a batch appeared nearly all males. The chief differences between 
them and the females are that the former are considerably smaller 
in size, about *018 inch long instead of about ‘025, which is the 
average length of the females. The body in the male is more 
elliptical, less diamond-shaped, the difference in shape being mainly 
the result of the smaller proportionate size of the mammillary pro- 
cess at the side. The anus, moreover, is prolonged in a short 
point, whereas that of the female is rounded. The penis, which is 
very long and cylindrical, is retractile within the abdomen, but 
emerges at the posterior end immediately above the anus, an 
arrangement unusual among the Acarina. The legs are rather 
stouter in proportion in the male and the hairs less strongly imbri- 
cated, and the inner pair at the posterior of the abdomen are 
smaller. I am not aware that the male has been previously ob- 
served. It is difficult to account for the males appearing so 
suddenly, but possibly the nubile females may be found at one 
time of year only — this I have not yet ascertained. 
