WATER MITES 45 



Limnocharidae, we find in the Hygrobatidae a variety of 

 colours. It so happens that the main colour of L. fulgida 

 is red, sometimes it appears there may be traces of an 

 impure yellow or dirty olive-green. On the dorsum there 

 are several dark patches. The more highly chitinised parts, 

 such as the legs, palpi, epimera, and capitulum, are blue, 

 some almost a bluish black. 



The eyes also present some differences ; instead of being 

 in a capsule, each pair of eyes is separated, the larger eye 

 being the anterior one. This, however, does not hold in 

 general for the group, the paired eyes being usually attached 

 to one another. The antenniform bristles are very fine. 

 A comparison of the epimera of the two species shows a very 

 marked difference. The groups have the same arrangement, 

 but the components are different. The first pair are long 

 and slender, and end posteriorly in a claw-shaped process. 

 On the inner edge, each of the first pair has an almost 

 quadrangular subcutaneous process nearly meeting together 

 on the median line. The interval between the second and 

 third pairs is small. The third pair is very much smaller 

 than the fourth. The third and fourth pairs have at their 

 anterior end a broad process on which a gland pore and 

 bristle will be noticed. Sometimes on that process the margin 

 of the third and fourth pairs becomes indefinite. The 

 capitulum is extended into a short rostrum, at the end of 

 which the mouth is situated. Slightly behind the mouth, the 

 palpi articulate with the capitulum. Most notable is their 

 size, the length being about half that of the body, and their 

 basal members about twice the thickness of the first pair 

 of legs. As is usual, the first segment is very short, the 

 second, however, is in this case about three times as long and 

 is very stout, as indicated above. Along the extensor (dorsal) 

 surface there are two rows of short pectinated spines, the 

 inner row having the larger number. About midway on the 

 flexor (ventral) surface the segment bulges out into a very 

 pronounced tubercle, at the apex of which there is a small 

 chitinous peg. This tubercle and peg supply a reliable key 

 to the identification of the Limnesiad species so far known 

 to Britain. The third segment is smaller, but the fourth is 



