386 PLEUROTOMID^:. 



character can be made out. The typical form has 

 occurred in a fossil state at Moel Tryfaen (Trimmer), 

 Macclesfield (Darbishire), Italian tertiaries (Philippi and 

 Calcara) ; and the variety elongata in the glacial drift 

 of Caithness (Jamieson). The geographical distribution 

 of this species at present is as follows : As to the typical 

 form, from the north of France (De Gerville and others) 

 to Madeira (M'Andrew), throughout the Mediterranean 

 (Risso and others), Adriatic (Heller and others), and 

 jEgean (Spratt) ; depths 4-25 f. : as to the variety 

 elongata, from Finmark (Sars) to Gottenburg, 10-30 f. 

 (Malm), Brittany (Cailliaud), and Vigo (M f Andrew). 



The animal is exceedingly active ; it gives out a very 

 dark purple dye, like that of Scalaria communis. Be- 

 tween thirty and forty years ago I observed the present 

 species burrowing in sand at Oxwich, near Swansea, on 

 the recess of a high tide; and I also procured it by 

 dredging on the same coast. The Rev. R. N. Dennis 

 tells me that specimens from Seaford Bay, when placed 

 in a basin of sea-water, crawled to the edge and sus- 

 pended themselves by a thread. A monstrosity which 

 I found at Tenby (where P. nebula is very abundant) 

 has the spire twisted and curved on one side. 



Among the synonyms may be mentioned P. Ginnania- 

 num of Philippi (who, by the by, omitted to notice the 

 spiral striae), P. nigra of Potiez and Michaud, and 

 Raphitoma polita of Brusina. According to Verany it 

 is the Mangelia costulata of Risso's collection. Clavatula 

 nebula of Searles Wood is not our species. 



7. P. L^EVIGA'TA*, Philippi. 



P. lavigatum, Phil. Moll. Sic. i. p. 199, t. xi. f. 17. 



BODY clear white, speckled all over with opaque white : pal- 

 * Rubbed smooth ; properly levigata. 



