WORMS. INTESTINA. 10. Hirudo. 129 



and feldom above aline long, linear when in motion and extending 

 to about 3 lines in length. 



33. Pi. alba. White with bro\vn ramifications, depressed, 

 curled at the margin, rather pointed at the end. 



On aquatic plants. Linn. Trans .2. p. 316, Hirudo. 



Body ovate when at rest, linear and 6 or 7 lines long when in mo- 

 tion, tranfparent on the margin: eyes 2 : ovary oblong, pointed at 

 the ends, with ufually 2 livid'fpots. 



34. PI. viridis. Green with a transparent margin, de- 

 pressed, oblong, pointed at the tail. 



Cold Streams Linn. Trans, i.p. 93. tab. 7. Hirudo. 



Body about the eighth of an inch long, grafs-green, nearly circular 

 when at rest : eyes 2, black : eggs 5 or 6, oblong, deep brown. 



10. HIRUDO. Leech. 



35. H. sanguisuga. Elongated, olive-brown, with an 

 ochre-yellow marginal band. 



Stagnant waters. Barbut Worms, p. 20. tab. z.f. 6. 



Body 4 or 5 inches long, deprefsed, fmooth, glofsy, above -dull 

 olive-black with a dirty yellow margin each side, beneath paler 

 with often a few black fpots : ta?7 thicker than the head. 



36. H. 'medicinalis. Elongated, olive-black, with 6 yel- 

 low-ferruginous lines above, and spotted with yellow 

 beneath. 



Stagnant waters, Barbut Worms, p. 19. t. 2./. 5.' Horse-leech. 



Body about 2 inches long, compofed above of numerous annular 

 wrinkles, and marked with longitudinal variegated stripes: mouth 

 fmaller than the .tail, armed with 3 cartilaginous teeth : tail com. 

 pofed of an annular mufcle by .which it attaches itfelf, 



37. H. octoculata. Elongated, yellow-brown, with 8 

 eyes in the form of a crescent. 



Stagnant waters. Act. Stocfth. 1757. t. 6,f. 58. 



Body about an inch and a half long, fometimes immaculate, feme- 

 times marked with variously coloured fp,ots or lines : eyes often 9. 



38. H. stagnate. Elongated, whitish with grey dots, 

 plaited at the sides : eyes 2. 



Wet hollows. Act. Stockh. 1757. t. 6. /. 9-11. 



Body about 9 lines long, pellucid : eggs about 401 furrounded by a 

 tranfparent circle, grey becoming brown. 



39. H. compldnata. Dilated, grey, with a double tuber- 

 cled line on the back, serrate at the sides. 



Slow Streams. Act. Stockh. 1757. tab.6,f, 121.4. 

 ' Body about 4 lines long, with tranfverfe bands compofed of 3 pale 

 lines;, whitish at the edges: head pointed, white : eyes 6 : tail orbi- 

 cular. 



40. II. geometra. Elongated, yellowish-green, with a 

 longitudinal row of white spots. 



Shallow Streams Br. Zool, iv. t. 20. /. 13. Barbut t. a./. 7. 



Bodv about 8 lines long, fometimes brownish, varying in colour, 

 tapering before, very broad at the tail : eyes 4 : bach carinate when 

 in motion". 



41. H. circulate. Oblong, pointed towards the head, con- 

 vex above, Hat beneath, dull red. 



The Thames. " Sowerby's Brit. Mifc. tab. 76. 



Body about an inch long when extended, convex and obscurely 

 striatc on the upper side, flat and paler beneath. 



42. II. crentita. Slightly depressed, greenish-grey, sub- 



