TAPES. 387 



often beautifully coloured with smoother strife and decussa- 

 tions. In the former case they are the Venus perforans ; 

 in the latter the Venus puUasira of authors." 



This shell is littoral, and does not appear ever to range 

 beyond the laminarian zone. It lives buried in gravelly 

 sand, muddy gravel, or in crevices of rocks,' and roots of 

 Larainarise. It is very generally distributed around our 

 coast, but rather local ; usually, however, plentiful where- 

 ever it does occur. Among localities may be cited : — 

 Gorey in Jersey, in crevices of submarine granite rocks 

 (S. H.) ; "Plymouth in hard limestone" (INIontagu) ; 

 Falmouth (Cocks) ; Exmouth in the shingles near the new 

 rope-walk (Clark) ; Dartmouth in seven fathoms water, 

 dead (M'Andrew and E. F.) ; Poole (E. F.) ; at Hastings 

 and at Margate, in blocks of chalk near the jetty (S. H.) ; 

 Littlehampton (Strickland) ; Scarborough abundantly 

 (Bean) ; not uncommon in the shale rocks of Durham and 

 Northumberland (Alder) ; Swansea and other places in 

 South Wales (Jeffreys) ; Anglesea (M'Andrew) ; Isle of 

 Man, but scarce (E. F.) ; Clyde (Smith) ; Hebrides (Jef- 

 freys) ; Zetland, littoral and as deep as seven fathoms 

 (Jeffreys, M'Andrew, E. F.) ; Aberdeen and Banff, both 

 varieties (Macgillivray) ; Frith of Forth, plentiful at low 

 water, especially near Newhaven and Cramond (E. F.) ; 

 Ireland. 



The Tapes pidlastra is confined to the Celtic and Scan- 

 dinavian seas, and dates its origin from the Pleistocene 

 epoch. 



