SANGUISUGA. 



posterior ones. Ring's from ninety to a hundred. Eyes rep- 

 resented by ten blackish points. Mouth tri-radiate. Jaws 

 cartilaginous, armed with numerous cutting teeth. Anus 

 small, placed on the dorsum of the last ring. 



THE SPECIFIC CHARACTERS. 



Species I. SANGUISUGA OFFICINALIS, HIRUDO PROVINCIALIS, 

 the Green Leech. Back greenish or blackish green, with six 

 rusty-red, band-like longitudinal stripes. Belly olive-green, 

 unspotted. 



II. SANGUISUGA MEDICINALIS, HIRUDO MEDICINALIS, the true 

 English or Speckled Leech. Back greenish, or olive-green, 

 with six rusty-red longitudinal stripes which are mostly spot- 

 ted with black. Belly greenish yellow, spotted with black. 

 Spots very variable in size and number ; in some cases they 

 are but few, in others they are so numerous as to form the 

 almost prevailing tint of the belly, the intervening spaces 

 appearing like greenish yellow spots. 



NATURAL HISTORY. 



LEECH, Hirudo. A genus of suctional animals or red- 

 blooded worms, of aquatic habits, provided with a sucker at 

 both ends of the body ; the greater part are inhabitants of 

 fresh water; some, however, are only found in the sea, while 

 others live in moist situations near stagnant water, pursuing 

 earth-worms, &c. Many of them accumulate their eggs 

 into cocoons, enveloped by a fibrous excretion, at first sight 

 so closely resembling sponge in structure as to have been once 

 mistaken by a distinguished naturalist for a new genus of 

 that family. 



The common Leech, Hirudo medicinalis, affords the most 

 interesting example of a suctorial Annelidan, and principally 

 deserves our attention. The outward form of one of these 

 animals is familiar to every one, and their general habits too 

 well known to require more than a very brief notice. The 

 body is very extensible, and divided by a great number of 

 transverse lines into numerous rings, extremely apparent in 

 the contracted state of the animal, but nearly imperceptible 

 when the body is elongated. The skin is soft, being merely a 

 thin cuticular pellicle separable by maceration, and the surface 

 is lubricated by a copious secretion of mucus. Beneath the 

 cuticle is a layer of colored pigments, upon which the colors 



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