British Oribatidse. By A. D. Michael. 193 



The abdomen is rounded in front and projects over part of the 

 cephalothorax ; it is truncated posteriorly, allowing a short, slightly 

 bifid projection at a lower level, to be seen ; this bears two thick 

 hairs curving inward. The whole abdomen is conspicuously 

 reticulated by ridges which under a high amplification are 

 resolved into chains of raised granulations ; these ridges divide the 

 abdomen into irregular spaces, of very varying shapes and sizes, 

 but all angular, not curved ; the reticulations have a tendency to 

 be largest and of the most regular forms in the centre, longest in 

 the median line towards the hind margin, and smallest towards 

 the lateral margin. There are four rows, each consisting of four 

 thick, curved hairs on the notogaster (dorsal surface of the 

 abdomen), and two extra ones on its anterior margin. 



Found at the Land's End, usually in moss. 



Nymph, PI. VI. Fig. 4. 



Rostrum and remainder of cephalothorax about equal in length. 

 Abdomen about twice the length of the two together. Eostrum a 

 cone, truncated anteriorly, and having four very small projections 

 on the truncated edge, the outer pair bearing short, curved hairs ; 

 remainder of the cephalothorax oblong and much broader than 

 long. Abdomen sharply divided from cephalothorax, and raised 

 above it. The rostrum and central part of the cephalothorax 

 covered by a hard, dark brown, chitinous plate, rough with raised 

 dots ; the anterior part of this plate bears two slightly raised ridges, 

 joined by a cross ridge posteriorly where they are widest apart ; 

 the angles formed by the longitudinal and transverse ridges are 

 prolonged backward so as to reach the stigmata, which are raised, 

 and surrounded by similar ridges. The remainder of the cephalo- 

 thorax and the whole of the abdomen are light brown or yellowish 

 white. The legs are like the chitinous plate on the cephalothorax. 



The stigmatic hairs are rather short, and increase regularly 

 but slightly towards the tip. The legs are thick and strong, the 

 two front pairs the thickest, the hind ones the longest, the fourth 

 pair when extended reach considerably beyond the hind margin of 

 the abdomen. 



The abdomen is oblong but sharply narrowed a short distance 

 from the posterior margin, the angles of which are prolonged into 

 short, blunt points ; a narrower hind margin, lower in level, projects 

 beyond the central j»art of the upper margin and also has ])roduced 

 angles. The general ellect of the aUlomen is of being almost fiat 

 with indented markings ; this arises from the edges being nearly as 

 high as the centre, but the edge, which is broad and convex and 

 cut into a series of undulations or lumps, lias an irregular, 

 depressed, concave channel, bordering it ou the inside, and within 

 this again the dorsal surface is raised so as to form three pairs of 



VOL. III. o 



