SOME PARASITIC ACARI. 



401 



parasitic, living among the bairs, and they are furnished with the 

 most remarkable apparatus for holding these hairs, to which the 

 females of the present species cling so tenaciously that the grasp 

 is often not relaxed even in death. The species now described is 

 very much smaller than that previously known. 



The second species is a Symhiotes, one of the Sarcoptidse, and 

 is a parasite of the hedgehog. I regret that I was not able to 

 find the male of this species ; but I only had one hedgehog, the 

 parasites were extremely few upon it, and these few were most 

 difficult to catch, running up and down the quills of the hedge- 

 hog and about between them with great rapidity. 



The third species, which is very minute, does not appear to fit 

 satisfactorily into any known genus ; I have therefore been forced 

 to institute a genus, " Q-oniomerus,'^ for it ; the species will of 

 course serve as a type for the genus ; it would be too soon to 

 attempt to define the latter accurately in any other manner, 

 particularly as the present species is so extremely minute as to 

 render detailed observations of it most difficult. 



Mtocoptes tenax, n. sp. (PI. XXVI. figs. 1-7.) 





Male. 



Female. 





mm. 



mm. 





•15 



•20 to '21 





•11 



•10 



Length of 1st and 2nd legs, without the 







claws, about 



•06 



•06 





•03 



•02 



Length of 3rd leg, without claw 



•04 



•04 



Length of claw of 3rd leg 



•03 



•02 



The colour and texture in both sexes is very similar to that of 

 the only other known species of the genus, viz. M. muscuUnus, 

 except as mentioned below. 



Male. — Diamond-shaped, the division between the cephalothorax 

 and abdomen well marked by a nearly straight transverse line, 

 the body being slightly constricted at this point. Outline of 

 cephalothorax slightly and irregularly undulated ; that of the 

 abdomen on each side convex anteriorly, then concave, and again 

 convex posteriorly. The abdomen is not divided posteriorly into 

 two pointed projections as in M. musculinus, but comes to a single 

 central bluntish point. On each side of this point is a square 

 projection, from each of the two outer corners of which springs a 

 very long and powerful hair. Thus there are two pairs of these 



