456 BULLID.E. 



Hebrides (Barlee and others); Firth of Forth (Fleming, 

 fideY.kU.); Moray Firth (Gordon); Aberdeenshire 

 (Dawson) ; Shetland (Barlee and J. G. J.): depths 18- 

 70 f. Bohuslan (Loven); Norway, in 30-60 f., sandy 

 mud (Danielssen) . The variety is from Shetland. 



" The animal flaps the sides of the foot upwards and 

 downwards, as if beating the water, with considerable 

 quickness, especially when first taken from the sea." 

 (Clark's MS.) 



The fry is devoid of sculpture ; it differs from that of 

 P. quadrata (which is also smooth) in being much 

 smaller at the top, and in having the sides angulated 

 and projecting. 



C. Smooth ; spire conspicuous. 



7. P. ni'tida^, Jeffreys. 



Shell oblong, convex, very thin and fragile, nearly trans- 

 parent, and of a polished lustre : sculpture, none on the body- 

 whorl ; but the spire has two keels or ridges, one at the outer 

 edge of each whorl, and the other in the middle, giving this 

 part an angulated appearance : colour clear-white, becoming 

 opaque in dead specimens : spire flattened, placed somewhat 

 obhquely ; it is quite exposed and occupies the top of the shell : 

 whorls 2|, irregularly twisted, but distinct: suture deep and 

 excavated: mouth oval, truncated above, wide and rounded 

 below ; its area equals about two-thhds of tbe under surface : 

 outer lip expanded, squarish at the top, and gently curved in 

 the middle ; it is level with the spire, viewed mouth down- 

 wards, and is below it, viewed mouth upwards ; outer corner 

 angular and projecting ; inner corner considerably receding and 

 acute-angled : inner lip forming a broad glaze on the upper 

 part, and reflected on the pillar ; there is no umbilical groove 

 or depression. L. 0'075. B. O-Oo. 



Habitat : Skye (J. G. J.) ; Haroldswick Bay, Unst 



* Glossy. 



