What is "hirudo medicinalis"

Bloodsucker \Blood"suck`er\, n.

1. (Zo["o]l.) Any animal that sucks blood; esp., the leech ( Hirudo medicinalis), and related species.

2. One who sheds blood; a cruel, bloodthirsty man; one guilty of bloodshed; a murderer. [Obs.]
   --Shak.

3. A hard and exacting master, landlord, or money lender; an extortioner.

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.

   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.

   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.

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

   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.

Medicinal leeches are any of several species of leeches, but most commonly Hirudo medicinalis, the European medicinal leech.

Other Hirudo species sometimes used as medicinal leeches include (but are not limited to) Hirudo orientalis, Hirudo troctina, and Hirudo verbana. The Mexican medical leech is Hirudinaria manillensis, and the North American medical leech is Macrobdella decora.