180 Transactions of the Society. 



confounded with the tectum ; it is quite smooth and hairless. The 

 lateral wing-like exjDansions («) are broader than long, that is to 

 say, the measurement is greater in a line drawn transversely across 

 the body than in a line parallel to the median line from rostrum to 

 anus ; the wing-like expansions do not extend further back than 

 the coxae of the fourth pair of legs. 



Found near Epping, in Sphagnum, usually under water. 

 Common. 



Nym;ph, PI. IV. Fig. 7. 



Semi-transparent white, some of the raised lines on the cephalo- 

 thorax chitinous brown, legs yellowish. Rostrum short, bluntly 

 conical for a short distance, thence almost parallel-sided, overlapped 

 in the middle by the point of a roughly triangular marking or 

 shield, which forms the upper surface of the remainder of the 

 cephalothorax, its base resting on the anterior margin of the 

 abdomen. A few irregular raised lines or ridges are found on 

 the upper surface of the cephalothorax. A pair of strong spines 

 stand erect near the point of the rostrum. The interstigmatic hairs 

 are similar, and the stigmatic hairs are filiform. Legs rather thick, 

 armed with short, stout spines on the tarsi, the usual long hair on 

 each fourth joint ; each leg of the first two pairs is set on a rounded 

 protuberance of the body. A red spot near each of the stigmata, 

 probably some internal organ, shows through by transparency. 



Abdomen about twice as long as broad, attaining its full width 

 immediately behind the anterior margin, which is straight and 

 bordered by two or three almost straight ridges. The abdomen is 

 shield shaped, the anterior part being almost parallel-sided flat, 

 with the edges raised, and divided into broad, irregular, shallow 

 ridges or wrinkles, which become more curved as they get farther 

 back, and enclose two concentric, nearly elliptical ridges near the 

 posterior margin. All the ridges have large raised dots u-regularly 

 scattered over them. On each anterior angle of the abdomen is a 

 stout straight spike, and there are about ten others, slightly curved, 

 along the margin of each side, pointing backwards, and set into 

 papillfe. Abdomen convex below, anus set far forward. 



The nymphs are generally found rolled up in a subaqueous 

 Sphagnum leaf. 



49. Oribata ovalis. Nic. 



Nic. 438. 



I found two specimens of what seems to be this species at 

 Epping Forest ; the wing of the tectum, however, is prolonged to a 

 point instead of being cut short as in Nicolet's drawing. Nicolet 

 says that perhaps this is the calcaratus of Koch ; this seems to me 

 doubtful. 



