19-1 



DB. C. T. TEECHAIA^X OX INTEEGLACIAL [vol. lxx\\ 



IX. Pleistocene Mabine Mollesca feom Dueham. 



The following is a revised list of the marine shells that I have 

 collected in the Durham Drifts, including additional species found 

 during the last four years. They are from two separate and 

 distinct deposits, as follows: — 



(a) The Scandinavian Boulder- Clay at "Warren-House Gill. 



(b) The Late Glacial kaims and gravel-heaps at Sheraton, and 

 some smaller gravel-hills similar in origin to these kaims. 



(Those marked with an asterisk are Arctic forms now extinct in 

 British Seas.) 



Scandinavian Drift. 



*Pecten islandicus Miiller. 

 Mytilus sp. 

 Leda cf. pemula Miiller. 



Cardium edule Linnaeus (rare). 

 *C. islandicwm Linnaeus (common). 

 *C. grcenlandicum Chemnitz (?). 



Cyprina islandica Linnaeus (common). 



Astarte sulcata Da Costa. 



A. elliptica. Brown. 



A. compressa Montagu. 

 *A. borealis Chemnitz. 

 *A. arctica J. E. Gray. 



Mya cf. truncata Linnaeus. 



M. arenaria Linnaeus. 



Panopsea norvegica Spengier (?). 



Saxicava rugosa Linnaeus. 



Saxicava large form (cf. S. arctica 

 Linnaeus) . 

 *Tellina (Macoma) calcarea Chemnitz. 



T. (Macoma) balthica Linnaeus (rare). 



Lvcina borealis Linnaeus. 



Pectunculus sp. (a fragment). 

 *Cyrtodaria siliqua Spengier. 



Natica cf. groenlandica Beck. 



N. cf. clausa Broderip & Sowerby. 



Buccinum, a small form (cf. B. gram- 

 landicum Chemnitz). 

 *Neptunea cf. despecta Linnaeus (a 

 fragment). 



Valves of Balanvs and tubes of Serpvla. 



Sheraton Kaims. 



Cyprina islandica Linnaeus. 

 Tellina balthica Linnaeus 



(common). 

 Saxicava sp. 

 * Astarte cf. borealis Chemnitz, 

 A. cf. elliptica Brown. 

 Mactra sp. 

 Turritella communis Bisso. 



Cybtodaeia siliqea Spengier. (Fig. 4, p. 195.) 



This is one of the most interesting shells that occur in the 

 Scandinavian shelly clay. It is fairly common, but always more or 

 less fragmentary, though the pieces are easily recognizable if any 

 part of the hinge remains. 



The Durham fragments seem to have belonged to specimens of 

 moderate size, measuring approximately (when restored) 52 mm. 

 in length. 



