SCROBICULAR1A. 445 



rounded on the anterior side, truncate or bluntly angular on 

 the posterior side, which is obscurely angulated and has a de- 

 cided gape, nearly straight on each of the dorsal sides, which 

 form by their junction with the beaks an angle of from 60 to 

 70 degrees : beaks very small and calyciform, inclining a very 

 little, if at all, towards the posterior side ; umbones project- 

 ing : ligament rather long and continued between the beaks 

 to the anterior side, dark horncolour : cartilage large, bent 

 like one of the knee- timbers of a ship, yellowish-brown : hinge- 

 line obtuse-angled : hinge-plate thick, short, broad in the mid- 

 dle and tapering gradually to each side: teeth, in the right 

 valve two thin, laminar, nearly parallel cardinals, the anterior 

 being mostly higher but shorter than the other ; in the left 

 valve a straight laminar cardinal which is often double ; the 

 sides of the hinge-plate are callous or ridge-like, and serve the 

 purpose of lateral teeth in keeping the hinge more securely 

 closed : inside polished and somewhat nacreous, minutely and 

 indistinctly striated lengthwise, and microscopically fretted like 

 seal-skin ; margin bevelled and sharp-edged : pallial scar dis- 

 tinct, with a large triangularly oval sinus, as in S. tenuis, but 

 having the upper angle more rounded : muscular scars rather 

 deep, of an irregular shape, anterior oblong, posterior trape- 

 zoidal. L. 1-5. B. 2. 



HABITAT : Beds of mud and clay, at low- water mark, 

 and as deep as 4 fathoms seawards, on all our shores 

 from Exmouth (Clark) to Aberdeen (Macgillivray), as 

 well as in Ireland and the west of Scotland : it is gre- 

 garious. Fossil in a raised sea-bed at Swansea disco- 

 vered in the course of excavating the South Docks (Mog- 

 gridge) ; similar deposit at Belfast (Hyndman and Grain- 

 ger) ; York and Forth beds (Smith) ; Sussex tertiaries 

 (Godwin- Austen). Scandinavian coasts from Bergen to 

 Kiel Bay, France from Boulogne to Nice, Vigo and 

 Malaga, Algeria, Spezzia, Naples, and Sicily. 



The name of this species may have been derived from 

 the peculiar flavour of the animal. Montagu says that 

 it has an extremely bitter taste although the old pro- 

 verb occurs to one's mind when we learn from Capel- 



