NATICA. 217 



edge: inner lip broad, considerably thickened on the lower 

 part, and forming a callous ridge just below the junction of the 

 outer lip with the periphery ; it is reflected over the pillar 

 and a great part of the umbilicus ; this is narrow, and further 

 contracted by a broad and obliquely twisted buttress, issuing 

 outwards towards the base from the centre of the cavity on 

 the side of the pillar: operculum thin, lemoncolour, closely 

 and irregularly striated in the line of growth, and marked in 

 every direction with microscopical short and curved scratch- 

 like lines ; spire irregular, denned by a broad chalky-white 

 suture, and terminating in a minute nucleus. L. 0*85. 

 B. 0-85. 



HABITAT : Not uncommon in muddy sand, at a con- 

 siderable distance from the coasts of Northumberland, 

 Durham, and Yorkshire, in 40-60 f. (Bean and others) ; 

 Shetland (Barlee). Fossil in the Scotch "drift" for- 

 mation (Smith and others) ; 20-25 f. on the Turbot- 

 bank, co. Antrim (J. Or. J.); Bridlington (Wood); Kel- 

 sey Hill, near Hull (Prestwich) ; Norwich Crag (Wood- 

 ward); Uddevalla (J. G. J.); glacial and post-glacial 

 beds in Norway, the former at 0-460 and the latter at 

 3040 feet (Sars) ; "post-pliocene" deposits, Canada 

 (Dawson) . Recent on the coasts of Scandinavia, Faroe 

 Isles, Iceland, Greenland, White Sea, and Sea of 

 Okhotsk, north-east and south-west America, from the 

 shore to 150 f. 



It appears to be a delicate animal, as it scon dies 

 when kept with other and more hardy mollusks. The 

 fishermen at Staithes call it the "white snail." Mr. 

 Howse tells me that it takes the bait freely, and that, 

 when the lines are drawn, it gripes or drives the hook 

 into its body and is thus caught. Very young speci- 

 mens of this Natica have a semicircular pad on the out- 

 side of the pillar, which projects over the umbilicus and 

 covers part of it ; this grows into the buttress or ridge- 

 like process mentioned in my description of the shell. 



VOL. IV. L 



