60 THE PURPLE-SHELL. 



the bottom, expanding, as it proceeded, its beautiful 

 starry flower of branchiae in the centre of its back. 

 When this and the horns are concealed, the animal 

 bears a curious resemblance in size, form, colour and 

 warty surface to the half of a lemon, divided longitudi- 

 dinally. 



THE PURPLE DYE. 



These two days past I have been experimenting on 

 the dye of Purpura lapillus. Hundreds of this shell 

 may be seen adhering to the rocks between tide-marks, 

 some quite white, or discoloured only with age, while 

 others, (frequently all found in one particular locality) 

 are rather prettily marked with three broad bands of 

 yellow or brown, running spirally round the whorls. 

 The latter variety is much more furrowed than the 

 white variety, and the bands of colour are often divided 

 into several narrow lines separated by the ridges. The 

 inner part of > the mouth, especially in old specimens, 

 is often tinged with purple, which may help an unini- 

 tiated observer to identify the species. They congre- 

 gate together, and you may easily collect, at low- water, 

 as many as you please. The best way to kill them 

 that I know is to break the shell to pieces with a 

 hammer, moderating the blow cautiously, so as not to 

 crush the soft animal, and then, having shaken off the 

 fragments, throw it into a basin of cold fresh- water, in 

 which the creature presently dies. With the shell 

 unbroken, I find it has the power of resisting the 

 action of fresh-water for a time far longer than would 

 be fatal to many marine Gasteropoda ; for some that 



