382 British Hydrachnidce : The Genus Fiona. [Sess. 



having each one acetabulum, with about three hairs, and the 

 posterior plates having about 20 acetabula each, nearly of 

 one size. 



Mole. — About 0'90 mm. in length, darker in colour than 

 female, and not so oval in shape. It is best recognised by 

 the genital plates surrounding the anus, and also by the 

 plates extending along the outside edge of the fourth pair 

 of epimera, as far as the articulation of the fourth leg with 

 the epimeron. Each plate with about 27 acetabula. The 

 patella has two hairs at the distal end. (Plate XXXIV., 

 figs. 35-41.) 



Localities. — Eppiug Forest and Lincolnshire. Not common. 



11. Fiona longipalpis, Krend. 



Female. — Body about 2-70 mm. long, of a beautiful bright 

 red colour, with very faint dark markings on dorsal surface. 

 Malpighian vessel hardly visible. Chitinous parts of body 

 a dark slatey-blue colour. This applies to all the limbs, as 

 well as the genital plates and epimera. Genital plates large, 

 each having a large number of acetabula, with two — one on 

 the anterior edge and one near the centre — much larger 

 than the others. Acetabula all on the plates, none free on 

 the ventral surface. The most prominent feature of this 

 mite is the one it derives its name from — viz., the large 

 and well-developed palpi which have two large hair pegs 

 on the flexor edge of the fourth segment of each palpus, 

 almost as noticeable as the pegs on the palpi of Atax 

 crassipes, Miill. 



Male. — Measures about 2 "10 mm, in length, of the same 

 bright colour as the female. Plates with a large number of 

 acetabula, two being larger than the others as in the female. 

 Tarsus of the third leg terminated with two small modified 

 claws. Distal end of patella with six or seven swimming- 

 hairs. Seminal pocket heart-shaped. (Plate XXXV., figs. 

 42-47.) 



Localities. — Very common on the Norfolk Broads. 



12. Fiona nodata, Miill. 

 Female. — Body about 2*70 mm. in length. Colour red 



