NATICA. 219 



and rapidly enlarging ; the last occupies ten-elevenths of the 

 spire ; the upper part of each (especially of the body -whorl) 

 is compressed or sometimes flattened, so as to present a bluntly 

 angular edge in front : suture rather straight, very narrowly 

 excavated inwards : mouth equal in area to nearly one-third 

 of the shell, and in length to two-thirds of the spire, expand- 

 ing and decidedly angulated at the base : outer lip gently in- 

 curved above, and having a blunt edge : inner lip broad and 

 remarkably thick, forming above a callosity or small protu- 

 berance, which is separated from the outer lip at its origin by 

 a short and shallow groove ; it is reflected over the pillar and 

 upper part of the umbilicus, and has a stain of pale chocolate ; 

 the middle portion is spread further backwards and forms an 

 angular pad: umbilicus rather large and deep, for the most 

 part open; a broad ridge winds spirally inwards down the 

 centre and towards the base of the shell ; it exhibits also two 

 or three parallel indistinct grooves and some striae : operculum 

 horncolour, narrowly edged with pearl-white, microscopically 

 and closely striated in the line of growth ; last whorl (as 

 usual) excessively large, defined by a white overlapping suture ; 

 termination or nucleus of the spire concave. L. 1*3. B. 1-2. 



HABITAT : Muddy sand in 7-90 f., Shetland (M'An- 

 drew, Barlee, and J. G. J.) ; west of Scotland (Forbes 

 and others); Moray Firth (Gordon); Firth of Forth 

 (Knapp); Dunbar (Laskey); Exmouth, dredged with 

 N. catena (Clark) ; St. George's Channel, between Scilly 

 and the Smalls (M f Andrew); Lough Strangford (Dickie); 

 Dublin Bay (Kinahan); Youghal (Miss E. Ball, fide 

 Thompson); Cork (Humphreys); between Cape Clear 

 and Baltimore (M f Andrew) ; Arran Isle, co. Galway 

 (Barlee). Fossil in the south of Italy and in Sicily 

 (Philippi); Coralline Crag (Wood, as N. cirriformis of 

 Sowerby and probably N. proximo} . Its foreign range 

 in a living state appears to be entirely southern, viz. 

 south-west of France (Fischer); Gibraltar, 12 f., and 

 Malaga, 30 f. (M f Andrew); Corsica (Susini); Naples 

 and Palermo (Scacchi and Philippi) ; Algiers, caught 

 by a fishing-line in deep water (Weinkauff) . 



L2 



