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THE BOOK OF CHOICE FERNS. 



it from further molestation. Its slender body, when fully extended, is about 

 3in. long, of a dirty yellow colour, with brown specks, rarely pale yellow, and 

 sometimes entirely black. The hinder part of its back is provided with a 

 small, ear-shaped, flat, greyish shell, about Jin. long, which protects the rear 

 of the animal when in the burrows. This slug, which bears the name of 

 Testacella haliotidea (Fig. 20), is known to occur in many localities in the South 

 of England ; and, according to Professor Trail (in Nicholson's " Dictionary of 

 Gardening," iv., p. 19), has been found as far north as Kirkcaldy, in Fifeshire. 

 There exists another species, named T. Maugei, possessing the same insecti- 

 vorous nature, indigenous in South-west Europe, but which has, however, 

 naturalised itself in the neighbourhood of Bristol ; it differs from the one 

 above mentioned by the uniform dark brown colour of its body, and by 

 the larger dimensions of its shell, which is the external character distinguishing 

 both species from the ordinary slugs so justly feared in the Fernery on 

 account of their depredations. 



