Macrobdella decora

Leech Leech, n. [OE. leche, l[ae]che, physician, AS. l[=ae]ce; akin to Fries. l[=e]tza, OHG. l[=a]hh[=i], Icel. l[ae]knari, Sw. l["a]kare, Dan. l[ae]ge, Goth. l[=e]keis, AS. l[=a]cnian to heal, Sw. l["a]ka, Dan. l[ae]ge, Icel. l[ae]kna, Goth. l[=e]kin[=o]n.] 1. A physician or surgeon; a professor of the art of healing. [Written also {leach}.] [Archaic] --Spenser. [1913 Webster]

Leech, heal thyself. --Wyclif (Luke iv. 23).

2. (Zo["o]l.) Any one of numerous genera and species of annulose worms, belonging to the order {Hirudinea}, or Bdelloidea, esp. those species used in medicine, as {Hirudo medicinalis} of Europe, and allied species. [1913 Webster]

Note: In the mouth of bloodsucking leeches are three convergent, serrated jaws, moved by strong muscles. By the motion of these jaws a stellate incision is made in the skin, through which the leech sucks blood till it is gorged, and then drops off. The stomach has large pouches on each side to hold the blood. The common large bloodsucking leech of America ({Macrobdella decora}) is dark olive above, and red below, with black spots. Many kinds of leeches are parasitic on fishes; others feed upon worms and mollusks, and have no jaws for drawing blood. See {Bdelloidea}. {Hirudinea}, and {Clepsine}. [1913 Webster]

3. (Surg.) A glass tube of peculiar construction, adapted for drawing blood from a scarified part by means of a vacuum. [1913 Webster]

{Horse leech}, a less powerful European leech ({H[ae]mopis vorax}), commonly attacking the membrane that lines the inside of the mouth and nostrils of animals that drink at pools where it lives. [1913 Webster]