208 BRITISH HYDRACHNIDiE. 



without the swimming-hairs, are nevertheless well covered with 

 short hairs, which on the inner edge of the legs are arranged in a 

 line and are stiffer in form than the others. The tarsus is thinner 

 than the other sections of the leg and not quite so long as the 

 preceding internode. The ungues are very small and nearly 

 hidden in the bristles which grow on the extreme end of the tarsi 

 (see Fig. 3). The palpus is five-jointed, the second and third 

 internodes being short and thick, the fourth is longer and more 

 slender ; like the legs, the palpi are covered with minute hairs. 



Colour, scarlet, some being found deeper in colour than others. 

 Some appear to be very deep in colour in the central portion of 

 the dorsal side and the margin to be much paler. The legs are 

 paler in colour than the body and are inclined to yellow at the 

 joints. 



Texture. — With the exception of the epimeral plates the whole 

 surface of the body is soft-skinned. The cuticle appears to be 

 finely striated and not covered with papillae. I cannot find any 

 external difference to denote the sexes. 



Eyes, four, in two pairs, close together. They have the appear- 

 ance of being connected on the dorsal surface with a small band of 

 cliitine, like a pair of spectacles ; in colour they are very dark red. 



The mouth-organs are very curious. In place of the mandibles, 

 which project and, as a rule, are so conspicuous in other species of 

 water-mites, is a round, sucker-like hole or depression (see Fig. 2). 



Distribution. — Very common. I have taken specimens at 

 nearly all the collecting-grounds round London. The greatest 

 number of specimens I have taken in one day was at the Warren, 

 Folkestone, in Aug., 1896. 



Larva. — Long in shape and hexapod. On Aug. 26, 1896, I 

 put a few Eylais extende?is in a tube by themselves. On Aug. 28 

 a quantity of ova was deposited on the side of the tube of a deep 

 red colour, in a yellow, gelatinous-looking film. On Oct. 2 the 

 larvae left this gelatinous mass and were free-swimming. They are 

 a deep red colour, like the adults, and seemed to be quite as much 

 at home out of the water as in ; but they did not display that 

 eagerness to get out of it that I found with the larvae of DipIodo7i- 

 tus despiciens (Miill.). They are very highly cultured, and the 

 hairs on the legs are quite clear, not pectinated. Eyes wide apart, 



