TWO NEW SPECIES OP HYDRACARINA OR WATER-MITES. 281 



was spoiled. The dissections were then mounted, two in 

 glycerine jelly and one in Canada balsam. On examination 

 of the mounted material it was seen, however, that the results 

 of the first examination were quite correct : — each eye-capsule 

 standing alone or separate on the body skin of the mite. 

 There was no visible connection, neither bridge nor chitinous 

 ridge such as has always been seen in the case of all species 

 of Eylais previously examined. In these circumstances I feel 

 bound to conclude that the water-mites Mr. Wilson sent me are 

 at present undescribed, and I propose therefore to do so, 

 giving this nova of the genus Eylais the name Wilsoni. 



Eylais Wilsoni sp. nov. 

 Plate 21. 



The four specimens received were females; about 3 '70 mm. 

 in length, rather a large size. Of the usual shape and colour 

 and in all respects, so far as external characters are con- 

 cerned, resembling when alive all other species of the genus. 

 The actual measurements of the body are about the same as 

 those of the type species E. extendens Miill., which it resembles 

 except in the eye area, where a difference is found. In 

 Eylais extendens Miill. the eye- capsules are connected by a 

 bridge of chitin, the anterior portion of which is about level 

 with the front edge of the capsule ; the posterior margin is also 

 deeply incurved. In E. Wilsoni, however, there is no connec- 

 tion whatever, the capsules being isolated on the integument. 

 The figures (PI. 21, fig. 1) show the position they occupy in 

 relation to each other. The width across the outside of the cap- 

 sule is about 0*4:8 mm., the length about 0"28 mm. The anterior 

 lens is set a little way in from the anterior margin, and the posterior 

 lens occupies about the same position as in the case of the type 

 species. Each capsule is more or less surrounded by a chitinous 

 projection from which on the anterior inner margin arise the 

 usual bristles. 



The capitulum (PI. 21, fig. 2) including the pharynx is about 

 1 mm. in length, by about 0*74 mm. in breadth; the inside of 

 the oral area is about 0*12 mm. The air-sacs reach nearly to the 

 posterior margin of the pharynx; the anterior lateral processes 

 are long and wide; the pharynx projects beyond the posterior 



