172 
The British Leeches 
and 256 (embryology); Carlet, 1883a, p. 448 and 1883b (fixation of suckers); 
Schultze, 1883, p. 87, figs. 15, 16 (nephridia); Bourne, 1884 (nepbridia, etc.) ; 
Whitman, 1884, p. 76 (external morphology) ; Haycraft, 1884, p. 478 (secretion of 
an anticoagulin); Bertelli, 1887, p. 284 (salivary glands); Apathy, 1888 a; Apathy, 
1888b; Apathy, 1889a, p. 267 ; Griffiths, 1889, p. 346 (nephridia); Biedermann, 
1891, p. 434 (nerve fibres); Retzius, 1891 (nervous system); Henking, 1892, 
p. 319, pi. xxxiii (digestive tract) ; R. Blanchard, 1893 k, p. 44 (in Syria) ; R. 
Blanchard, 1894 b (in Italy, descr.); Croockewit, 1894, p. 427 (jaws); Burger, 
1894, p. 440 (embryology); Graf, 1894a, p. 485 (nephridia); Bertelli, 1896, p. 147, 
pi. ii (pharyngeal glands); Apathy, 1897, p. 37, pis. iv—vi (glands); Scharff, 1898, 
p. 193 (in Ireland); Goodrich, 1899, p. 477, pis. xlii—xliv (communication between 
vascular system and coelom); Schuberg, 1899 (reproductive organs); Havet, 
1899, p. 73 et seq. (nervous system); Allen, 1902, p. 161 (topography of internal 
organs); Spiess, 1902, p. 548 (digestive tract); Livanow, 1903 (neuro- and myo- 
somite); Spiess, 1903, p. 151 (digestive tract); Fage, 1904, p. 1450 (nephridia); 
Spiess, 1905a, pp. 415 and 577, and 1905b, pp. 333 and 506 (biliary pigments). 
Hirudo venesector, Braun, 1805, p. 24, pi. xi, figs. 1—9 (coloured). 
Medicinal Leech , Kurzmann, 1819, p. 312. 
Sanguisuga medidnalis, Savigny, 1822, p. 114; Savigny, 1826, p. 456; Risso, 1826, 
p. 428; Moquin-Tandon, 1826, p. 114, pi. v, fig. 2; Fischer, 1827, p. 440, figs. 
1—4; Brandt et Ratzeburg, 1829, p. 238, pi. xxviii, figs. 3—17 and A—M 
(coloured, except figs. 10—17), pi. xxixA, figs. 1—58 (anatomy), pi. xxixB, figs. 
1—11 (anatomy), and pi. xxx, figs. 5—25 (embryology, etc.); de Filippi, 1837, 
p. 26; Wedeke, 1842, p. 183 ; Wedeke, 1843, p. 296; Brightwell, 1842, p. 13. 
Sanguisuga officinalis , Savigny, 1822, p. 330; Savigny, 1826, p. 457 ; Moquin-Tandon, 
1826, p. 112, pi. v, fig. 1 ; Fischer, 1827, p. 441, figs. 5—10; Audouin, 1829, 
p. 109; Brandt et Ratzeburg, 1829, p. 237, pi. xxx, figs. 1 and A, B, G 
(coloured). 
Hirudo provindalis, Carena, 1820, p. 282, pi. xi, figs. 4, 5 ; Brandt et Ratzeburg, 1829, 
p. 237 (syn. S. officinalis), pi. xxx, fig. 1 * and M (coloured). 
Hirudo verbana, Carena, 1820, p. 285, pi. ix, fig. 6. 
Hirudo officinalis, Derheims, 1825, pp. 9 and 11. 
Sanguisuga verbana, Moquin-Tandon, 1826, p. 117, pi. vi, fig. 1; Audouin, 1829, 
p. 109; Brandt et Ratzeburg, 1829, p. 235, pi. xxx, fig. 2 (coloured) ; de Filippi, 
1837. 
Sanguisuga carena, Risso, 1826, p. 429. 
Sanguisuga obscura, Moquin-Tandon, 1826. 
latrobdella ( Hirudo ) medidnalis, de Blainville, 1827, p. 254. 
Iatrobdella medidnalis, de Blainville, 1828, p. 561, pi. xxxv, figs. 4 and 4 a—4 d, also 
pi. xxxvi, figs. 1—3 (varieties); Egidy, 1844, p. 113, figs. 62, 63. 
Sanguisuga chlorogaster, Brandt et Ratzeburg, 1829, p. 238, pi. xxviii, figs. 1, 2. 
Diagnosis. Body elongate, flattened, widest at about the sixteenth 
somite, tapering anteriorly and posteriorly, capable of contracting into 
the form of an olive (Moquin-Tandon). 
Dorsal surface usually olive green, richly variegated with reddish 
brown, yellowish green, orange and black, and exhibiting an extremely 
