64 THE SCOTTISH NATURALIST 



distance between the capsules themselves, a small thin plate 

 with a thick outer edge like that of H. halberti {Joe. cit., pi. 21, 

 fig. 21). 



Eyes. Eye capsules large, about 75 mm. apart. Median eye 

 lying midway between the eye capsules, surrounded by a thin 

 chitinous ring, elliptical in outline, with a major axis of 75 p 

 and a minor axis of 60 \x. 



Rostrum extending about as far as fifth segment of palpi ; slender, 

 bent sharply downward from the stout tapering capitulum. 



Mandibles of normal form, proximal end slightly turned up. Length 

 about 275 mm. 



Pa/J>i. Length 2 mm. Second segment curved, tapering from the 

 thick basal segment to the long and slender third segment. 

 Fifth segment very small, opposed to a short process arising 

 from the distal end of the small fourth segment, giving the tip 

 of the palpi a cheliform appearance. Scarcely any hairs dis- 

 cernible, except a row of very short ones along extensor 

 surface of second segment. 



Epimera. First and second pairs of normal form, with a small 

 claw-shaped process projecting from the margin of the first 

 pair beneath the second pair. Outer posterior portion of third 

 pair inflated and overlapping fourth pair. Inner end of third 

 pair broad, rather more of a rectilineal than the commonly 

 rounded form, with a short subcutaneous spur extending to the 

 genital shield. Inner margin of fourth pair lying nearly parallel 

 to median line, and ending in a securiform subcutaneous 

 process. 



Legs.-- First pair 2-62 mm.; second pair 2-92 mm.; third pair 

 3-30 mm. ; fourth pair 4-65 mm. Short stiff hairs on the 

 extensor surface of proximal segments curved, becoming 

 straighter towards distal extremity ; those of the flexor surface 

 longer and quite straight. Swimming hairs on the fourth and 

 fifth segments of last two pairs of legs. Hairs on the sixth 

 segment of all legs, and on the fifth segment of the first two 

 pairs very short and inconspicuous. Claws simple and 

 relatively small. 

 Genital Plate. --85 mm. broad by 75 mm. long, lying well within 

 the area between the third and fourth pairs of epimera of each 

 side. Deeply cleft on the median line. Acetabular areas 

 convex, with an approximately ovate outline. 



Distribution. England : Norfolk Broads. 



