W. A. Harding 
171 
Series 2. Monostichodonta. 
•Jaws with or without papillae and armed with a single row of 
numerous sharp teeth. 
Genus: Hirudo, Linnaeus, 1758. 
Synonymy : 
Sanguisuga, Savigny, 1822. Iatrobdella , de Blainville, 1827. 
Jaws devoid of papillae and armed with less than 100 sharp teeth. 
Crop with ten pairs of lateral caeca of which the last and longest pair is 
reflected posteriorly. Genital openings separated by five rings. Upper 
lip of anterior sucker not divided inferiorly by a longit udinal groove. 
Hirudo medicinalis, Linnaeus, 1758. 
Plate XV, Figs. 36—38. Text Figs. 12 and 13 (pp. 170 and 174). 
Synonymy and Literature: 
Hirudo major et varia, Gesner, 1558, p. 503. 
La Sangsue , Rondelet, 1558, p. 169. 
Hirudo varia, Aldrovandus, 1602, p. 763. 
Hirudo minor variegata, Muralto, 1685, p. 579. 
Bloetsuyger, Swammerdam, 1737, p. 62. 
Hirudo depressa, nigra ; abdomine subcinereo, Linnaeus, 1746, p. 365. 
Hirudo nigrescens, flavo-variegata — the Common Leech, Hill, 1752, p. 16, pi. ii. 
Hirudo medicinalis, Ray, 1710, p. 3 ; Dillenius, 1719, Cent. 7, pi. v, figs. 1—4 ; 
Bergman, 1757, p. 308, pi. vi, figs. 1, 2; Linnaeus, 1758, p. 649; Gisler, 1758, 
p. 95 ; Salomon, 1760, p. 35; Linnaeus, 1761, No. 2079; Weser, 1765, p. 41 ; 
Pennant, 1766, p. 36 ; Linnaeus, 1767, p. 1079; Shaw, 1769; 0. F. Muller, 1774, 
p. 37, No. 167 ; 0. F. Muller, 1776, p. 219, No. 2658 ; Barbut, 1783, p. 19, 
pi. ii, fig. 5 ; Gmelin, 1788, p. 3095 ; Cuvier, 1798, p. 632 ; Bose, 1802, p. 245, pi. 
viii, fig. 6; Draparnaud, 1803, p. 31; Turton, 1806, p. 68 ; Turton, 1807, p. 129; 
Pennant, 1812, p. 69 ; Oken, 1815, p. 368; Cuvier, 1817, p. 532; Stewart, 1817, 
p. 356; de Blainville, in Lamarck, 1818, p. 291 ; Bojanus, 1819, p. 468, pi. f, 
figs. 1—5 ; Carena, 1820, p. 279, pi. xi, figs. 1, 2 ; Delle Chiaje, 1823, p. 47 ; 
Bruguiure, 1824, p. 131, pi. Ii, figs. 1, 2 ; Fleming, 1822, p. 604 ; Leach, 1824, p. 
451, pi. xxvi; Payraudeau, 1826, p. 17 ; Fischer, 1827; L. G. Muller, 1830; Milne- 
Edwards, in Lamarck, 1835, p. 520; Moquin-Tandon, 1846, p. 327, pis. vii—xi; 
Johnston, 1846, p. 442 ; Diesing, 1850, p. 465 ; Grube, 1851, p. 109 ; Dalyell, 1853, 
p. 26, pi. iii, fig. 11 (coloured); Ranke, 1875, p. 152, figs. 1—12 (eyes); Hermann, 
1875 (nervous system); Ollson, 1875, p. 3 ; Bourne, 1880, p. 283, pis. xxiv and xxv 
(nephridia); Lankester, 1880 a, p. 85 ; Lankester, 1880 b, p. 305 (intra-epithelial 
capillaries); Lankester, 1880 c, p. 307 (connective tissue); Schneider, 1880, pp. 19 
