TAPES. 381 



shape is cordate lanceolate. The umbones are rather pro- 

 minent, and somewhat inclined ; the beaks small, very 

 acute, and much inflected ; the internal surface is whitish, 

 with generally a stain of purple behind the teeth ; the 

 hinge as in aurea. The form is occasionally abbreviated, 

 and the beaks, though rarely, if ever, in our native exam- 

 ples, are stained with a beautiful violet. The length of 

 our largest example is about two inches and a quarter, and 

 its breadth an inch and five-eighths. 



The animal of Tapes decussata has frequently been ob- 

 served ; indeed, considering what a favourite article of 

 food it is in many parts of the continent, it would have 

 been very strange had everybody swallowed it without ex- 

 amination. As long ago as 1710 it was figured and de- 

 scribed by Keaumur. It is oval, white and thick, and 

 has the margins of the mantle, which are freely open, or- 

 namented with a conspicuous scalloped white fringe. The 

 sii^hons are separate to their bases and equal, yellowish and 

 white, dotted towards the base and centre, marked with 

 tawny or reddish or dark-brown specklings and cloudings 

 near their orifices. These are fringed, the branchial with a 

 double border of twelve long cirrhi and as many alternating 

 small ones, the anal with nearly twenty or so simple cirrhi, 

 in both cases of a brown colour. The branchial, according 

 to Mr. Clark, are suboval, the upper the smaller, and all of 

 a pale brown colour. The labial palps are proportionally 

 small and triangular. The foot is large, white, lanceolate, 

 and furnished with a byssal groove. 



Except locally, this is rather a scarce shell. It is usually 

 dug out near the shore, being rarely, if ever, taken by the 

 dredge. It is sometimes, but seldom, procured on the 

 Northumbrian coast (Alder) ; and at Scarborough (Bean) ; 

 on the south-west it is more frequent, occurring at Little- 



