56 POPULAE BRITISH CONCHOLOGY. 



posterior angle^ is boot-shaped. The shells are thin, 



and for the most part without colour. The British 



species are — 



S. intermedia : rather long, beaked ; apex nearly central. 



S. tenuis : short, nearly as broad as long, slightly coloured. 



8. alba : white, like all except tenuis, very inequilateral, with 



a fold and slight beak at the back. 

 S. pnsmatica : iridescent like the rest, longer than S. inter- 

 media, with the apex more on one side. 

 Y. ScROBicuLARiA. — Like Syndosmya, this genus has a 

 pit in the hinge for the inner part of the ligament, and 

 small narrow teeth at the sides of it ; but it has no la- 

 teral teeth. The animal has remarkably long siphonal 

 tubes with plain openings; the mantle fringed and 

 open, and the foot broad, tongue-shaped, and pointed. 

 The shell of iS'. compressa is flat, shaped like the broader 

 species of Tellina, and of a very pale yellowish colour. 

 " Chiefly found at the mouths of rivers or inlets not remote 

 from fresh water ; and though never beyond the flux of the 

 tide, yet it delights in situations where the fresh water is oc- 

 casionally flowing over. It principally inhabits sludge or 

 muddy places, buried to the depth of five or six inches." 

 [Montagu^ Found at Scarborough, Liverpool, Cork, Erith 

 of Perth, etc. 



