CONTRIBUTIONS TO THE BRITISH FAUNA. 245 



4. Hirudo ^'crmcosa. 



Encyclop. 7e Liv. des PI. d'Hist. Nat. — Helminthologie, 

 P]. 52. fig. 5. 



Head dilated ; margin smooth, with six small 

 tubercles or warts. Body round, thickest at the 

 base, tapering towards the head, and. composed 

 of numerous warty rings. There are upwards of 

 fifty large rings, w^itli many intermediate smaller 

 ones. These rings are studded in the middle with 

 about twelve retractile warts. Tail nearly the 

 size of the head, smooth and dilated. Length 

 when stretched, nearly one foot. 



Found on the skate and thornback in Zetland 

 and Leith. It leaves a black mark behind ; and 

 ^fter being removed, is very tenacious of life. 



This species bears a near resemblance to the 

 H. muricata of Linnaeus. It may even prove to 

 be the same, as I have never seen any specimen 

 which I was convinced was the true H. muricata. 

 The figure of H. muricata, as given by Linnasus 

 in the Museum Adolphi Friderici, (and afterwards 

 copied by Pennant into his British Zoology,) pos- 

 sesses two horns or teeth, which are very conspi- 

 cuous, and the head is considerably smaller than 

 than the tail. In the species above described, 

 there are no appearances of horns or teeth, and 

 the head is dilated, and nearly of the size of thq 



0.3 



