NOTHRUS SYLVESTRIS. 491 



very easily distinguished from it. Professor Canes- 

 trini is, in my opinion, entirely in error in identifying 

 this species with N. ])alustvis (' Prospetto dell'Acaro- 

 fauna Ital.,' p. 30). Prof. Berlese seems to me to be 

 equally in error in stating this species to be the N. 

 biciliatiis of Koch. For the identity of Nothrus sylves- 

 tris and N. Anauniensis, I rely entirely on Berlese, who 

 has had ample opportunity of examining Professor 

 Canestrini's specimens and states them to be identical. 



Both Canestriiii and Berlese state this species to be 

 didactyle, with one claw much smaller than the other ; 

 I do not think that this is correct ; hairs and claws are 

 of course processes of somewhat similar natures in these 

 creatures, and it is often difficult to distinguish between 

 them. In the present instance, if the whole creature be 

 looked at, there is something that looks much like a 

 small second claw, but if the tarsi be carefully dissected 

 off and examined with a high power, it will be seen 

 that the supposed second claw proceeds, not from the 

 clear chitinous rod at the end of the tarsus, which 

 always bears the claws in the OribatidcB, but from the 

 tarsus itself. I am, of course, supposing that the 

 learned Italian professors really had the N. sylvestris 

 of Nicolet under examination. 



Colour lio-ht chestnut-brown. 



Texture dull and reticulated all over, the fineness of 

 the reticulations varies in different parts of the body. 



Form almost a parallelogram, but the sides are 

 slightly curved and the rostrum is bluntly pointed. 



Cephalothorax darker in colour than the rest of the 

 creature, rough, finely reticulated (reticulations about 

 125 to the millimetre, pits three or four times as wide 

 as the ridges). Rostrum with a blunt rounded point ; 

 then the cephalothorax slopes outward at an obtuse 

 angle for nearly half its length, after this it becomes 

 more parallel-sided, but is indented for the insertion 

 of the first pair of legs, and finally it swells out again, 

 with a rounded outline on each side. These rounds 

 are formed by the bases of two almost hemispherical 



