SCALARIA. 93 



mark (Lilljeborg) to the Canary Isles (M' Andrew) in 

 the North Atlantic, as well as throughout the Mediter- 

 ranean, Adriatic, and iEgean. The depths given by 

 different authors varv from 8-40 f. : and Mr. M f An- 

 drew found this species alive on the shore at Vigo and 

 Gibraltar. 



Montagu says that the purple dye issues from a gland 

 behind the head : the great beauty of its colour was 

 first noticed by Plancus in Mediterranean specimens. 

 The shell is the " small stair-case " of Petiver, " bastaard 

 wenteltrapje" of the Dutch according to Klein, " barred 

 wreath " of Pennant, and u false wentletrap" of Da Costa, 

 the " true wentletrap ** being S. scalaris or pretiosa. 

 Our shell barely exceeds 2 inches in length. 



It is the Turbo clathrus of the 10th and previous edi- 

 tions of the ' Systema Naturae/ as well as of the ' Fauna 

 Suecica ; 3 but the species so named in the 12th edition of 

 the ' Systema' is described as having the base encircled by 

 a spiral keel or ridge, and is consequently not the British 

 species. Da Costa called it Strombiformis clathratus, ap- 

 parently from a habit, in which he indulged with a most 

 inconvenient pertinacity, of substituting new names for 

 old \ the latter specific name, not having been adopted 

 by any subsequent writer, must be considered obsolete. 

 Gmelin and Mohr evidently mistook the Turbo clathrus 

 of Linne for his T. clathratus, which is a Trophon. 



3. S. Trevelya'na*, Leach. 



S. Trevelyana, (Leach, M.S.) Winch, on the Geology of Lindisfarn, Ann. 

 Phil, new ser. iv. p. 434 ; F. & H. iii. p. 213, pi. lxx. f. 7, 8, and (animal) 

 pi. FF. f. 1-3. 



Body yellowish-grey or pale-fawncolour, with a faint tinge 

 of purple, minutely streaked and speckled with white : snout 



* Named in honour of the discoverer, Miss Emma Trevelyan. 



