XATICA. 223 



a clear-drab ground.'* It is not always so sluggish as 

 it seems. According to Mr. Bretherton (' Zoologist s 

 for 1858, p. 6232) it crawls quickly in pursuit of its 

 prey (chiefly Mactrce and Tellince), which it seizes by 

 means of its large and flexible foot, and, after drilling 

 their shells with its tongue, devours them while buried 

 in the sand. This will account for most of the small 

 round holes that are so often seen in bivalve shells 

 thrown up on the beach. I am not disposed to concur 

 in the opinion commonly entertained by naturalists that 

 the front of the tongue is worn away by use. That 

 portion is firmly and intimately connected with the 

 jaws; and it would be difficult to explain how such a 

 union could be dissolved or a new attachment formed 

 from time to time. The present species differs from 

 the last in its larger size and plumper form, the whorls 

 not being compressed at the top, its deeper and wider 

 suture, the umbilicus being grooved instead of ridged, 

 and particularly in the coloured streaks and the different 

 hue of the pad formed by the inner lip. 



It is the Nerita glaucina of Pennant, Pulteney, and 

 Donovan, but not of Linne, which is now considered a 

 tropical species — although under that name Linne evi- 

 dentlv included our shell with several others. Dale 

 called it Cochlea parva, Forbes Natica Nicolii. Potiez 

 and Michaud referred it to the N. ampullaria of La- 

 marck, Loven to his N. collaria, Deshayes to his N. 

 castanea, and Forbes and Hanley to his N. monilifera. 

 Without discussing the question which, if any, of these 

 Lamarckian species the one now under consideration 

 may have been, I prefer following Alder and Searles 

 Wood in adopting the older name given by Da Costa. 



