438 PATELLIDiE. 



Like most Limpets, this elegant little shell is liable to 

 a greater or lesser elevation of form and a corresponding 

 alteration of the basal outline. In the more depressed 

 individuals the latter is generally elliptical, and the Tertex, 

 which is always more or less anterior, is more inclined and 

 advanced ; in the more conical examples it is rounded- 

 oval, and the vertex is blunter and more central. The 

 shell is more frequently thin and subpellucid than other- 

 wise, and is never very glossy; it is not laterally compres- 

 sed, but, on the contrary, rather inclined to spread at the 

 sides. It is moderately arched behind, but is little convex 

 elsewhere ; the anterior slope, for the most part, is more 

 or less abrupt. The surface seems smooth, but when 

 examined displays, besides the fine wrinkles of increase, a 

 considerable number of obsoletely elevated, radiating lines. 

 The exterior is prettily radiated with pink or reddish liver- 

 colour ujjon a ground of greyish white or horn-colour, and 

 in full-grown specimens exhibits, occasionally, but not com- 

 monly, an additional kind of net-work in the paler portions, 

 lines of the darker hue immeshing, as it were, numerous 

 small and somewhat oval-shaped spots of the lighter tint. 

 The rays are generally twelve or fourteen in number, and 

 moderately broad ; they are much more conspicuous to- 

 wards the base, and, indeed, are generally obsolete upon 

 the vertex. The inside, if not coated with a thin layer of 

 porcelain white, faintly shows the external painting ; fre- 

 quently two short rays of a dark red colour emanate from 

 behind the vertex at acute angles to each other, so as to 

 resemble the letter V truncated at its narrower extremity. 

 The basal edge is quite entire, is rounded at both ends, and 

 more or less arched on each side. Our larger specimens 

 measure about five and a half lines in length, and four in 

 breadth. 



