(^93 ) 
V III. Defeription of the Hirudo viridis, a new Engli Leech, by George 
Shaw, M. D. F. R. S. Fellow of the Linnean Society. 
Read Dicosbér 2, 1798. 
|. MONGST the variety of {maller animals which I have oc- 
cafionally examined, there are fome which appear to me to 
have entirely efcaped the obfervation of naturalifts ; having no 
place in the Syftema Nature of Linnæus, or in any of the numerous 
publications which have from time to time added to the ftock of - 
natural hiftory ; fo that they may be confidered as abfolute non- 
defcripts, and as fuch may be thought more deferving a particular 
furvey. 
The animal which I now purpofe to defcribe is a fmall and very 
elegant fpecies of Hirudo or Leech, which is to be found in fuch 
. waters as are more than commonly clear and cold, or at leaft fuch 
as do not very eafily freeze during a common froft. This fpecies 
of Hirudois not much more than the eighth of an inch in length, 
and I have feen it even lefs. In its general fhape or outline it very 
much refembles the fpecies called Hirudo complanata, or the {mall 
black leech (except that the extremity of its body is of a fomewhat 
fharper form). The colour of this animal is a deep and beautiful 
grafs-green ; and, when magnified, a tranfparent edge or border ap- 
pears to furround it. 'The eyes are two in number, and of a deep 
black. 
