TWO NEW SPECIES OF HYDRACARINA OR WATER-MITES 279 



irregular. Third pair lying well up against the second pair and 

 fused with the fourth pair with a very indistinct line of demarca- 

 tion ; inner angle rounded, projecting well forward, the inner 

 margin weakly indented, extending obliquely outwards to the 

 rounded posterior margin (PI. 20, fig. 2). 



Capitulum without rostrum, slightly cone-shaped anteriorly, 

 sides almost straight, parallel, posterior margin straight ; man- 

 dible 0*27 mm. in length, distal end weakly sinuate, the edge 

 turned towards the body distinctly serrate, proximal end clavate, 

 the intermediate portion moderately arched. 



Legs. — First pair of legs about 0*53 mm. in length ; second 

 pair about 0'55 mm. ; third pair, 0'60 mm. ; fourth pair, 

 078 mm. The first segment of the first leg is very wide 

 and acetabular ; second segment with proximal flexor surface 

 slightly arched and with an oblique chitinous fold ; third, fourth 

 and fifth segments with proximal end contracted ; sixth segment 

 apparently devoid of hairs, claws very small and slender, distal 

 end thicker than proximal. The leg is rather sparingly supplied 

 with spines and bristles. First segment of second pair similar 

 to that of first pair but larger and broader ; the fifth segment is 

 rather more modified than usual, the proximal half of the flexor 

 surface bulging out very considerably, while the distal half is 

 concave. Sixth segment, distal end wider than proximal ; a 

 rather conspicuous feature here is the proximal end of this seg- 

 ment, which is bent nearly at right angles where it articulates 

 with the distal end of the fifth segment (PL 20, fig. 5) ; the claws 

 are similar to those of the first pair of legs, while the hairs, as in 

 the first pair, are not very numerous. Third pair of legs very 

 like the first pair, but each segment longer ; the claws are also 

 small and slender. Fourth pair : this pair requires more de- 

 tailed description. The extensor surface of the first segment 

 has two short spines on the distal half and another, longer, on 

 the distal margin ; the proximal portion of the second segment 

 is very much contracted, extensor surface with two short spines 

 and flexor surface with two moderately long ones at the distal 

 margin ; the distal end of third segment is much stouter than 

 the proximal, extensor surface has five spines and a shorter and 

 broader one at the distal end, the distal margin with four broad, 

 moderately long ones : fourth segment, extensor surface with 

 three pairs of spines, flexor surface with one very short spine in 



