380 PLEUROTOMID/E. 



nuata ; but this is mncli smaller, thicker, less slender, not 

 attenuated towards either extremity, nor glossy ; the base is 

 considerably broader in proportion; the ribs are stronger, 

 blunter, and more angulated, and there are only 7 (or at the 

 most 8) on the body-whorl; their interstices are somewhat 

 concave: the spiral strise are closer and finer: colour less 

 regular, with the lines and bands broader, sometimes mottled, 

 or the upper part of the shell chocolate, and the lower yellowish ; 

 the outside of the mouth and the throat or inside of the outer 

 Hp usually exhibit a purplish-brown blotch : spire less taper : 

 wJiorls not so convex, the last occupying three-fifths of the 

 shell : suture not so deep : mouth much narrower ; length two- 

 fifths of the shell : ca7ial more curved, shorter, and broader : 

 outer li]) continuous with the inner lip, considerably thickened 

 within, where it is frequently furnished with a narrow white 

 ledge; edge not so thin or sharp: Jahial notch much deeper: 

 inner lip thickened, and reflected above: pillar flexuous. 

 L. 0-45. B. 0-185. 



Habitat : Generally distributed -, living at low-water 

 mark of spring tides^ in rock-pools^ on the coasts of 

 Devon and Cornwall (Clark and Templer), in 95 i., on 

 fine sand, ofi* Unst (J. G. J.), and in 145 f. off" the Mull 

 of Galloway (Beechey) . The " P. coarctata "' of Forbes 

 is merely the northern, and consequently larger, form 

 of this common species. Fossil in the glacial deposit 

 at Wexford (Sir H. James) ; Belfast (Grainger) ; Red 

 and Coralline Crag (Wood); Norway, 70-80 feet, retain- 

 ing its coloured band (Sars); Lillo near Antwerp (De 

 Wael) ; Antibes (Mace) . Finmark to Bohuslan, 10-70f. 

 (Sars, Loven, and others); Zealand (mus.Copenh.); Brit- 

 tany (De Gerville and others) ; Arcachon (Fischer) ; 

 Rochelle (D^Orbigny pere) ; Spain and Portugal, 7-12 f. 

 (M'Andrew); Provence (Gay); Spezzia (J. G. J.); and 

 probably every part of the Mediterranean and Adriatic, 

 as P. tceniata and under otlier less known names. 



The Murex costatus of Pennant is a mixtm'e of small 

 shells belonging to different genera. Da Costa's Bucci- 



