178 
The British Leeches 
et seq. (cytoanatomy, etc.); Brandes, 1899, p. 122 (copulation); Havet, 1899, 
p. 69 et seq. (nervous system); Brumpt, 1900 (cocoon); Sukatschoff, 1900, p. 618 ; 
Schuberg, 1904, p. 629 (with parasitic Nematodes). 
Hirudo ( Erpobdella) vulgaris, de Blainville (partim), 1827, p. 259; Gervais, 1836, 
p. 629, pi. ccxi, fig. 7. 
La Nephelis vulgaire, Duges, 1828, pp. 312 and 335, pi. ix, fig. 8 (egg-capsule). 
Nephelis octoculata, Moquin-Tandon (partim), 1846, p. 302, pi. iii, figs. 1—11 
(coloured), 12—33 (anatomy); Thompson, 1846, p. 389 (in Ireland); Apathy, 
1888 a, p. 154, etc., pi. viii, fig. 12 (head region); Apathy, 1888 b; R. Blanchard, 
1892a, p. 171, fig 5, A and B (diagram of somite); R. Blanchard, 1893a, p. 31 
fig. 13, A and B (diagram of somite incorrectly copied from Blanchard, 1892, fig. 
5); R. Blanchard, 1893b, p. 8, figs. 3—5 (diagrams of annulation, etc.); R. 
Blanchard, 1893 e, p. 194 (identity with N. sexoculata, Schneider, established). 
(Not Nephelis tesselata (?), Brightwell, 1842, p. 13, pi. i, figs. 15—17 = Protoclepsis 
tessellata.) 
Hirudo octo-octulata, seu vulgaris , Dalyell, 1853, p. 14, pi. ii (coloured). 
Nephelis sexoculata , Schneider, 1883, pi. iv, fig. 4. 
Herpobdella octoculata , R. Blanchard, 1894 b, p. 52, figs. 15—17 (same as figs. 15— 
17 in Blanchard, 1893 b); Scharff, 1898, p. 194 (in Ireland); Evans, 1905, p. 215 
(in Scotland). 
Diagnosis. Body elongate, flattened, attenuated anteriorly, bluntly 
rounded posteriorly, of a uniform width posterior to the clitellum. 
Colour deep brown, yellowish or reddish brown, paler ventrally, 
sometimes with blackish markings and a median dark stripe on the 
dorsal surface. 
Somites I—IV uniannulate, V triannulate; the 18 somites 
VI—XXIII complete with five rings. Somites XXV—XXVII bi- 
annulate. 
[Somite XXIV usually with four rings, occasionally with five 
owing to the subdivision of the last ring, similarly somite XXV is 
sometimes triannulate owing to the transverse subdivision of the second 
ring.] Eight eyes. The first and second pairs lie in a transverse curved 
line on somite II; not infrequently the second (and outer pair) lie 
between somites II and III or entirely in somite III. The third and 
fourth pairs are situated on the first ring of somite V, but may encroach 
to some extent upon the succeeding ring. 
The male genital orifice lies between rings 36 and 37, that is, 
between the fourth and fifth rings of somite XI; the female orifice is 
four rings behind the male, between the third and fourth rings of 
somite XII. 
The anus lies between the two rings of somite XXVI. 
Length 30—50 mm.; width 2—5 mm. 
