OF THE COUNTIES OF NORTHUMBERLAND AND DURHAM. 243 
Criass. CONCHIFERA, Lamarck. 
Orver. LAMELLIBRANCHIATA, Blainville. 
Faminy. Teviripa, D’Orbigny. 
15. TELLINA, Linneus. 
1. T. DunELMENSIS, 7. s. 
Shell elliptical; beaks small, not prominent, situated near 
the anterior end, which is somewhat rounded ; posterior 
elongated more acute than the anterior; two cardinal teeth 
in each valve. 
In Magnesian-limestone, rare. Humbleton Hill. 
Differs very slightly in general outline from the Sanguinolaria 
Romeri, figured in the Geology of Russia. 
FamILy, 
16. SANGUINOLITES, MM*Coy. 
1. S. ELzeans, King. 
Allorisma elegans, King, Ann. Nat. Hist., xiv., p. 316. 
In Magnesian-limestone ; rather rare. Humbleton, Tunstall ? 
This fine species is generally badly preserved. It is a trans- 
versely elongated shell, with the posterior much lengthened and 
obliquely truncated, and the anterior short and acutely rounded. 
It is slightly constricted near the anterior extremity. 
FAmIty, 
17, EDMONDIA, de Koninck. 
1. E. ELONGATA, 7. s. 
Shell elongated oval ; beaks prominent, near the anterior 
end; anterior short, rounded ; posterior elongated, the 
dorsal margin on a line with the beak ; surface convex, 
covered with strong concentric lines of growth ; hinge mar- 
gin without teeth ; wmbonal cavity divided longitudinally 
by an elongated, thin, slightly-curved visceral plate, de- 
pending towards the cavity of the shell. 
VoL. I. Kk 
