PLEUROTOMA. 383 



somewhat flattened or shelf-like at the top, and angiilated by 

 the ribs ; the last whorl occupies six-elevenths of the shell : 

 suture deep : mouth narrow, compressed and acute-angled 

 above, and broader in the middle ; length nearly four-elevenths 

 of the shell : canal short, straight, and wide, expanding at the 

 extremity in full-grown specimens ; basal notch obliquely in- 

 curved : outer lip flexuous, slightly bent inwards ; edge sharp 

 and muricated by the extremities of the spiral striae : labial 

 notch small and short, situate on the shelf-like ledge at the top 

 of the body-whorl : inner lip retired, finely polished : pillar 

 short and nearly straight. L. 0-275. B. 0-1. 



Habitat : Mud among stones, and muddy sand, in 

 10-60 i., Weymouth (Thompson), Exmouth (Clark), 

 Torquay (Battersby and J. G. J.), Plymouth (Barlee and 

 Jordan), Falmouth (Barlee and Hockin), Cornwall 

 (M*^ Andrew), Whitburn (Alder), Dogger bank (Men- 

 nell), Bantry (Barlee), co. Antrim (Waller), Oban, 

 Skye, and Loch Carron (J. G. J., Forbes, and others), 

 Moray Firth (Gordon), Aberdeenshire (Dawson), Wick 

 (Peach), Shetland (M'Andrew and others). Newer 

 tertiaries at Tarento (Philippi). Christiansund, 40-50 f. 

 (Danielssen) ; Bohuslan (Loven, and in 16-50 f. Malm) ; 

 Loire-Inferieure (Cailliaud); Arcachon (Fischer); Co- 

 runnato Gibraltar, 8-30 f. (M 'Andrew); Malaga (M'An- 

 drew) to Naples (Philippi) on the European coast of the 

 Mediterranean, in 10-50 f., and on the North African 

 coast, in 35 and 36 f. (M 'Andrew and Weinkauff); Adria- 

 tic (Brusina); ^Egean (Forbes, /^e Reeve, as P. Cycla- 

 densis) . 



Most of the specimens which I received from the late 

 Mr. Clark under this name belong to a dwarf and deep- 

 water variety of P. nebula. The Clavatula brachystoma 

 of Searles Wood appears to be an extinct species. Loven 

 described our shell as Mangilia tiarula. 



