328 TELLINIDiE. 



in the left valve, interlocking between what may cither be 

 regarded as twin narrow teeth, or as a most broadly and 

 profoundly cloven single one. The pallial sinus is of the 

 most ample magnitude. Fine specimens occasionally reach 

 the size of two inches in length, and one-and-a-half in 

 breadth : the exact proportions are, however, very fluc- 

 tuating. 



The animal of this species has been frequently submitted 

 to examination, and some good figures of it have been pub- 

 lished : it is subtriangular, compressed, and yellowish, or 

 pale orange ; the mantle is freely open, and the margins 

 are only slightly and distantly fringed, or rather denticu- 

 lated, so that they sometimes appear as if quite jilain ; 

 the siphonal tubes are long, yellowish, and separate, their 

 extremities plain : they are very contractile ; the foot is 

 large, white, flat, tongue-shaped, and geniculated ; the 

 labia are very large, triangular, and pointed. Elaborate 

 figures of the anatomy of this animal have lately been pub- 

 lished by Deshayes in his gorgeous work on the Mollusca 

 of Algeria. 



As Montagu remarks, it is " chiefly found at the mouths 

 of rivers or inlets not remote from fresh water; and though 

 never beyond the flux of the tide, yet it delights in situa- 

 tions where fresh water is occasionally flowing over. It 

 principally inhabits sludge or muddy places, buried to the 

 depth of five or six inches." It is from the comparative 

 inaccessibility of such spots, that the species, although most 

 abundant, is not frequently taken alive, and that cabinets 

 are usually only furnished with dead valves washed on 

 shore after rough weather. It is common at Scarborough 

 (Bean) ; Liverpool (E. F.) ; Shellness, near Ramsgate (S. 

 H.) ; Littlehampton in Sussex, and Southend in Essex 

 (Strickland) ; in four fathoms near the Nore light, and 



