OF NORTHUMBERLAND AND DURHAM. 83 



2. U. MARGARITIFERA, Linil. 



AlasmodoH margaritiferus, Gray, Turt. Man. 293, t. 2, f. 9. 

 In mountain streams, and rivers in the early and more preci- 

 pitous part of their course. Very fine in the Reed above Otter- 

 burn. 



Family. Cardiad^, Fleming. 

 89. CARDIUM, Linnaeus, 



1. C. ECHINATUM, Linn. 



Cardium eckinatum, Mont. Test. Brit. 78. 

 In deep water, frequent. 



The Cardium aculeatum of Sir C. Sharp's list is probably a 

 variety of this. 



2. C. EDULE, Linn, (common cockle.) 



Cardium edule, Mont. Test. Brit. 76. 

 On some of our sandy shores, abundant. The cockles of Bu- 

 dle Bay are celebrated for their large size. 



3. C. fasciatum, Mont. 



Cardiumfasciatum, Mont. Test. Brit. Supp. 30 ; Loven, Ind. 



Moll. Scand. 35. 

 Cardi^cm exiguum, Hogg, Nat. Hist. Stock. 28 ? 

 In fifteen or twenty fathoms, and perhaps also in shallow 

 water, not uncommon. 



Our shell agrees perfectly with Montagu's description, with the 

 addition of spines on the posterior margin, which are very liable 

 to be worn off. Montagu's figure appears to have been taken from 

 the young of C. edule ; hence the difficulty there has been in as- 

 certaining the species. The C. elongatum of Turton's " Bivalves" 

 is a variety of this. 



4. C. NODOSUM, Mont. 



Cardium nodosum, Mont. Test. Brit. 81. 

 At the roots of corallines from the fishing boats, Whitburn, 

 rare. — Mr. R. Ilowse. 



5. C. NoRVEGicuM, Spengler. 



Cardium Icevigatum, Mont. Test. Brit. 80. 

 In deep water, not rare. 

 Cardium medium was introduced as a British species by 



M 



