The two principal fpecies of this genus which 

 our own country produces are the Hirudo fanguifuga 

 or Horfe-leech, and the Hirudo medicinalis or 

 ftriped leech, which is ufed with fo much fuccefs in 

 the pradice of phyfic. Thefe two fpecies are fome- 

 times confounded with each other, but may be rea- 

 dily diftinguifhed by proper attention to their re- 

 fpedive characflers. The Hirudo fanguifuga or 

 Horfe-leech is always of an olivaceous-black, more 

 or lefs deep on its upjD^r furface, and of a dull ochre- 

 color beneath, and the edges or fides of the body 

 are of the fame ochre-color as the lower parts; 

 giving the appearance of a very narrow margin on 

 each fide. This fpecies is very common in ftagnant 

 waters, ponds, ditches, &c. during the whole 

 warmer parts of the year, and frequently grows to 

 the length of fix or feven inches. The Hirudo 

 medicinalis or officinal fpecies fcarce ever attains to 

 fo large a fize, and in point of color is far more 

 elegant than the former. It is of a deepifh black 

 above, with a flight tinge of olive, and is marked 

 by fix longitudinal ochre-colored and fometimes 

 reddifh bands or fi:ripes: of which the two exterior 

 ones on each fide are interrupted by a chain of 

 longifh black fpots, while the two middle ones are 

 perfectly free from fpots. The lower furface of the 

 animal is deep-black, marked in a fomewhat irre- 

 gular manner with a double longitudinal feries of 

 large ochre-colored fpots In their general motions 

 and difpofitions both fpecies agree. They are both 

 viviparous, and produce their young in Autumn. 

 The teeth of the leech are three in number, and of 



