30 i HIRUDO. 
grass or humectation ; and they are distributed im Edinburgh and the 
neighbourhood, or even at some distance, in chip boxes. 
Of late, however, an extensive dealer has established himself in this 
city, to the great convenience of the public. 
A considerable traffic in leeches has recently sprung up between 
France and the province of Constantine in Africa. They are carried by 
the native Arabs in earthen vessels to the city of that name, and sold 
there at the rate of about half a guinea per thousand. The amount of 
this branch of trade is computed at £12,000 or £15,000 annually. 
Prats III. 
Fic. 11. Hirudo medicinalis. 
§ 7. Hirupo compLanata—Gilossipora tuberculata.—Dr James Rawlins 
Johnson.—Plate IV. fig. 1. 
It must be certainly accounted very absurd, though proposed by one 
of our most distinguished naturalists, to change the name, sufficiently 
established, of an animal, because some spot, wart, or tubercle, or a 
few additional stripes or hairs, happen to be observed which were pre- 
viously unnoticed. Therefore I prefer as explicit enough, the name 
formerly bestowed on the present subject. 
The Hirudo complanata, or flattened leech, extends an inch and a 
half in motion, and nine lines when at rest. It is comparatively thin, 
the body resembling the outer longitudinal section of a pear. Instead 
of the soft and flexible consistence of the preceding leeches, the body is 
rigid, and the skin somewhat hard, so that certain observers have as- 
eribed a crustaceous character to it; neither does the animal swim. It 
is remarkably quiescent, its motion always slow, and effected by bring- 
ing the sucker and the head in juxtaposition, when the head being re- 
lieved, is secured as a farther advance, and being secured again, the 
