NASSA. 353 



Habitat : Everywhere, on stony ground, from low- 

 water mark to 145 f. (Beechey) . Var 1. Channel Isles. 

 Var. 2. Filey Brigg; west coast of Scotland, 50-60 f. ; 

 Lerwick Sound. Var. 3. Whitburn (Alder); Conne- 

 mara (Barlee) ; Lerwick (J. G. J.) . This last variety, 

 although varicose, differs from N. jjygmcBa in the angu- 

 larity of the whorls, and in sculpture. Fossil in all our 

 quaternary deposits ; Norwich Crag (With am, fide 

 Woodward); Bed and Coralline Crag (S.Wood) ; glacial 

 and postglacial Norwegian beds, 0-460 feet (Sars); 

 Uddevalla, 40 feet (Malm and J. G. J.) ; upper, middle, 

 and lower Crag at Antwerp (Nyst); Italian tertiaries 

 (Brocchi and others); Vienna basin (Homes). The 

 present distribution in space of this common species is 

 not less extensive, viz. from Iceland (Steenstrup) and 

 Finmark (Sars and others) to the Azores (Drouet) and 

 throughout the Mediterranean, Adriatic, and jEgean; 

 depths, shore (M'Andrew) to 100 f. (Malm) . 



N. incrassata is a very active mollusk, and now and 

 then changes its crawling position by leisurely floating 

 with its foot upwards. It often gets into lobster- and 

 whelk-pots. In the half-grown shell the outer lip is 

 excavated within and folded inwards. The spawn-cases 

 are solitary, yellowish, and shaped like a round flask, 

 with a small neck or opening at the top. 



It is the " small Gibraltar Ruggle ^' of Petiver. Out 

 of 14 synonyms which I have collated it may be un- 

 necessary to specify more than Buccinum minutum, Pen- 

 nant, B. ambiguum, Pulteney, B. Ascanias, Bruguiere, 

 B. macula, Montagu, B. coccinella, Lamarck, and ap- 

 parently B. asperulum, Brocchi. B. incrassatum of the 

 ' Mineral Conchology '' is a different species. 



