PLATE XXXIII. 



whitish, yellowish, or brown, of various hues, sometimes uniform, or 

 without any markings ; at others, girdled spirally with darker colours. 

 The adults also are sometimes bright red, orange, chesnut, or whitish, 

 or olive, with, and sometimes without, the spiral lineations. They 

 vary no less in size than in colours ; and those of the Orkneys, in par- 

 ticular, are quadruple, the size of those on the Irish or English coast. 



It is said, the name Periwinkle is a corruption of Petty Winkle^ or 

 small Winkle, or Whelk. 



Fig. I. I., &c. Adult vanities of Turbo Littoreus. Fig. II. II. 

 tlie young shells. 



FIG. III. Ill, 

 TURBO RUDIS. 



THICK-LIFPED PERIWINKLE^ 

 SPECIFIC CHARACTER. 



Shell somewhat tapering, without umbilicus. Volutions of the spires, 

 or turban swelled. Lip thick, and glossy within. 



This shell has been kindly communicated by Dr. MatoUj as a new 

 species. It is noticed in the first volume of that gentleman's Obser- 

 vations on the Western Counties ; but has not, we believe, been 

 hitherto figured. It was discovered on the banks of the Tamar, in 

 Devonshire, near B:;re- Alston, and is thus described : 



