CHITON. 223 



discharge was so copious that the water in the vessel 

 became turbid. This was probably a seminal secretion. 

 The colour of the shell is extremely variable. Out of 

 more than five hundred specimens Bouchard-Chan- 

 tereaux was unable to find two marked exactly in the 

 same way. He describes the tongue as horny, bristling 

 with six longitudinal rows of small tricuspid teeth, those 

 of the two central rows being blackish and much 

 stronger than the others. C. marginatus differs from 

 C. cinereus in being usually of a larger size, narrower, 

 and more convex or arched; the plates are broader; 

 the colour is variegated, not streaked ; the sculpture is 

 much coarser, and not chain-like; the granulation of 

 the girdle is finer, more minute, and even ; the marginal 

 spines are stronger and more conspicuous; and the 

 edges of the plates are deeply notched, instead of being 

 slightly and indistinctly crenulated. The habitat of the 

 two species is also different ; this is littoral, while the 

 other prefers deeper water. In the fry of the present 

 species the front of each plate is curved. 



Two specimens of C. marginatus in Turton's collection, 

 affixed to separate cards, are named in the Doctor's 

 handwriting " Chiton ruber" " ; one from u Dublin Bay/' 

 and the other from a Portmarnock." They correspond 

 with his description of C. punctatus. Both have been 

 painted red ! A daughter of Dr. Turton told me that 

 when her father went out shell-hunting, some young 

 ladies would occasionally go before him on the beach, 

 and drop here and there shells which they had taken 

 with them, in order to play him a merry trick. Let us 

 suppose that these were the artists who so ingeniously 

 beautified the specimens above noticed, finding such 

 perhaps an easy feat compared with that which Shen- 

 stone's Laura could not accomplish — 



" With fresh vermilion paint the rose." 



