12G LITTORINIDiE. 



to become disconnected from each other, and the pemdt, 

 whose k^ngth is more than half its breadth, is remarkably 

 and disproportionately large, being equal in length to the 

 three preceding turns united. The apical whorl is obtuse, 

 and very small. The longitudinal increase of all but the 

 last volution is rapid. The suture is fine and very oblique. 

 The body occupies nearly one-half of the dorsal length, 

 but is scarcely broader than the preceding coil ; it is a 

 little produced at the base, where its declination is mo- 

 derate and rounded. The mouth may be considered short, 

 since it does not exceed the ventral length of the penult 

 turn ; it occupies from one-third, to at most two-fifths of 

 the entire length, is subovate, not much peaked above, and 

 is broad yet scarcely rounded at the base, where it recedes 

 rather than advances. The peristome is continuous, and 

 is sometimes disconnected from the body. The outer-lip 

 is sharp- edged, moderately arcuated, and slightly disposed 

 to expand. The pillar-lip is oblique, and, excepting 

 where it rounds off anteriorly into the outer one, is but 

 little arched ; it is reflected, rather narrow, and of nearl}^ 

 equal breadth throughout ; its inner edge is a little raised, 

 but is not accompanied by any umbilical fissure. Two 

 lines in length, and four-fifths of a line in breadth, are 

 the dimensions of rather a large example. 



This is a scarce and local species, ranging to deeper 

 water than its near allies. Exmouth (Jeffreys and Clark) 

 Tenby ; Oxwich Bay, near Swansea, (Jeffreys) ; Milford 

 Haven in twelve fathoms ; off" Skye in forty fathoms 

 (M'Andrew and E. F.) ; Oban (Barlee) ; Eda Sound, 

 &c., in Orkney, in forty fathoms (Thomas). Aberdeen 

 coast (Macgillivray) ; Zetland (Fleming). Birterbuy 

 Bay and Arran (Barlee) in Ireland. 



It occurs fossil in the coralline crag (Searles Wood). 



