British Oribatidse. Btj A. D. Michael 189 



down each side of the abdomen. The legs are broad and flat ; the 

 coxse of the first three pairs set almost at right angles to the rest 

 of the legs. Each leg diminishes regularly in width from near the 

 insertion of the trochanter to the tip of the tarsus. All the legs 

 except the coxse and inner sides of the fourth pair, bear strong 

 hooked spines along their edges at short intervals. 



Behind the anterior margin of the abdomen is a wide depression ; 

 posterior to this the back is elevated so as to form a low ridge in 

 the centre, occupying about a third of the width, and from the 

 ends of this longitudinal ridges run back, in an irregularly sub- 

 parallel direction to near the hind margin, where they approach 

 each other and join. The space within these ridges is depressed, 

 and a deepish but wide trench borders them on the outside ; from 

 the outer edge of this trench the body slopes up to the lateral 

 margin, and this slope bears a number of oblique and irregular 

 ridges, sometimes anastomosing, and becoming vague and confluent, 

 towards the hind margin. 



I have found the females so full of eggs that the abdomen was 

 greatly distended by them. 



I think it most probable that Koch's Nothrus venfricosus is the 

 same species as this but without the strips of cast skin. 



Found in moss in Epping Forest. Not common. 



Nymjyh. 

 This nymph is figured by Koch as a separate species under the 

 name of Nothrus furcatus, fasc. 30, pi. 3. 



Average length of full-grown nymph in 



inert stage to insertion of tail hairs "84 mm. 



Average breadth of back ' 21 „ 



„ length of legs, first pair .. '31 „ 

 ,, „ „ second pair. . "20 „ 



Colour semi-transparent white, the skin slightly granular. Crea- 

 ture four times as long as broad ; of this length about three-eighths 

 is the cephalothorax, over four-eighths the abdomen, and nearly 

 one-eighth the projection at the posterior end. Legs and rostrum 

 light brown. 



Cephalothorax conical at the apex, thonce nearly parallel over 

 half its length, then widening out rapidly to the width of and 

 nearly to the level of the back. 



Abdomen quite flat witli parallel sides about two-thirds of its 

 length ; thence curved slightly inwards, and terminated posteriorly 

 by two conical projections with a depression between them and each 

 terminated by a slightly curved si)ine. Inhere are four lumps on 

 the anterior margins each bearing a strongly curved spine, the two 

 central ones crossing. 



Legs thick and rather short. 



