BRITISH HYDRACHNID^. 



207 



1878. — Rylais e.xte?idens. A. Croneberg, Zool. A?iz., 1878, No. 14, 



p. 316, 

 1878. — Eylais extendens. Krendowsky, Die Metajnorphose Hydrach- 



fiiden, p. 8, PI. I., Figs, i and 2. 

 1879, — Eylais exiendens. Neiiman, Svenska Hand/ingar, p. 105, 



Twf. XIII., Fig. 4. 

 1880. — Eylais exte?ide?is. Murray, Economic Entomology, p. 150, 



Fig. 2. 

 1882. -Eylais extendens. Haller, Die Hydrach. der ScJmeiz,, 



p. 37, Taf. II, Figs. 9 — 13. 

 \%%l.--Eylais extendens. Griffith and Henfrey, Micro. Dictionary, 



p. 315, PI- VI., Fig. 28. 

 1885. — Eylais extendefis. Krendowsky, HydrachnidcE of Russia, 



p. 143, Taf. VIII., Fig. 23. 

 1887. — Eylais extendens. Barrois and Moniez, Cat. des Hydraclr 



nids Nord de la France, p. 36. 

 \^(^}^.— Eylais extendens. Koenike, Dr. F., Stuhlman in Ostafrika, 



P- 51- 

 1894. — Eylais extendens. Piersig., Zool Anz., No. 449, p. 215. 

 1895. — Eylais exfe7ide?is. Koenike, Die Hydrachniden Ort- 



Afrikas, p. 2. 

 1896. — Eylais extefidejis. Soar, Sci. Goss., Dec, No. 31, p. 170. 



The average length of the body is about 4*0 mm. ; width, about 

 3*12 mm. ; first leg about 2-40 mm. ; second leg about 2*50 mm. ; 

 third leg, 3*04 mm.; and the fourth leg, 3-60 mm. ; palpi, r2o mm. 



Shape of body ovate, the smallest end to the front. The 

 dorsal side is well rounded (see PI. XII., Fig. i). The epimera 

 are hard, chitinous plates let into the ventral surface, the two first 

 pairs being joined together side by side ; the two last pairs touch 

 only at the small ends, the marginal ends where the legs are 

 hinged being wide apart (see Fig. 2). The largest ends of the 

 epimeral plates are also furnished with a quantity of small hairs ; a 

 few are also present here and there to about half-way down the 

 epimera plates. 



Legs, eight, four on each side, which gradually increase in 

 length from before backward ; they are strong and chitinous, and 

 covered with small hairs, the first, second, and third pairs being 

 supplied with swimming-hairs only. The fourth pair, although 



