84 EDIBLE BRITISH MOLLUSKS. 



south-west of Tyrone, and one at Ardfry Point. The 

 Creggaun heap consists principally of the shells of the 

 oyster, mussel, and common cockle, though the whelk, 

 Pecten varius, periwinkle, limpet, Nassa reticulata, He- 

 lix nemoralis, Trochus, and Venerupis decussata {Tapes 

 decussata ?), are also found in it. There are also layers 

 of wood-ashes and stones, apparently used as hearth- 

 stones, showing the marks of having been subjected to 

 fire, but no weapons. " The heap occupies an irregular 

 space of two hundred feet long, and sixty feet wide, and 

 ranges from six to eight feet deep." There are various 

 traditions as to the age of the heaps ; and it is said, 

 that ninety years ago a series of high tides cast up the 

 heap of shells from adjoining beds.* 



At the present day the Baltic appears to be almost 

 the only sea where the oyster will not grow, — a fact at- 

 tributable to the very great influx of fresh water from 

 the mouths of its many rivers, and the less powerful 

 current from the ocean, so that, in the words of Sir 

 Charles Lyell, " The Ostrea edulis cannot live at present 

 in the brackish waters of the Baltic, except near its en- 

 trance." Yet, from the examination of the Danish 

 Kjokkeomoddings, it appears, " that the oyster flou- 

 rished in places from which it is now excluded, attaining 

 its full size." 



Oysters may be eaten in various ways, either cooked 

 or raw. 



" The pepper-box, the cruet, — wait 

 To give a relish to the taste ; 

 The mouth is watering for the bait 

 Within the pearly cloisters cased. 



* The ' Field,' February 4th, 1865. 



