NATICA. 329 



Zoophyte by Ellis, and was characterised as such by 

 Gmelin under the name of Flustra arenosa. Its true 

 nature was first surmised by Mr. Boys, and in 1823 Mr. 

 Hogg communicated an interesting paper to the Linnean 

 Society, in wdiich he demonstrated it beyond question to 

 be the nidus of Natica monilifera. 



The animal is entirely of a yellowish hue, deepening into 

 yellow on the sole of the foot, and more or less tinged with 

 purple above ; especially on the anterior portion, which, 

 when contracted, is thickly veined with purplish brown. 

 The foot is very large, and capable of great expansion, 

 rounded in front and behind, and extending far around the 

 shell, which is partially concealed by the reflected mentum 

 and operculigerous lobe, both paler in colour than the rest 

 of the body. The tentacula are long and lanceolate-tri- 

 angular, white, or tinged with reddish-brown ; there are 

 very minute sessile eyes at their external bases beneath. 

 The operculum is corneous. Our figure of the animal is 

 taken from a drawing by Mr. Spence Bate. 



Though a common, this is at the same time rather a 

 local species, being found, however, on most parts of our 

 coast where sand is plentiful. It abovmds, buried in sand, 

 in many places not far below low- water-mark, and ranges 

 as deep as ten or fifteen fathoms. 



It is general throughout the Celtic region of the Euro- 

 pean seas ; and dates its genealogy from later tertiary 

 times. The absence of colour and the decortication of the 

 sutural margins of the whorls in fossil specimens of this 

 genus, render their identification with recent species 

 extremely difficult and obscure. 



VOL. ur. u u 



