PSAMMOBIA. 273 



For an account of the animal of this shell, we are in- 

 debted to Mr. Clark, who examined and noted living 

 specimens at Exmouth, as long ago as 1835. It is sub- 

 oval, elongated, compressed, and of a yellowish-white 

 colour throughout. The edges of the mantle are finely 

 fimbriated. The tubes are long, and appear to be rather 

 wider than in the following species. The lower one is 

 usually, though not always, curved shorter than the upper, 

 truncate at its extremity, and perforated with six rays. 

 The upper siphon is curved, and terminates in an irregular 

 margin. The foot is very large, broad, rather thick and 

 linguiform. The branchiro hang obliquely from the dorsal 

 range, and consist of a pair on each side, the upper being 

 shorter and smaller than the lower, of a brown colour, 

 rather coarsely pectinated, each pair united with the oppo- 

 site pair posteriorly, and each branchial lamina free at its 

 lower edge. There are also a pair on each side of lighter 

 coloured, elongated, pointed, triangular labia, smooth on 

 their outer surface, well pectinated on the inner, nearly 

 lying on each other, and of equal length ; each pair is con- 

 nected with the other by a membrane surrounding the 

 mouth. 



It is a locally abundant shell, and is usually collected 

 upon the sands after a succession of rough gales ; it dwells 

 near the shore, and may be taken at low tides in muddy 

 sand, burrowing but a little depth from the surface. 

 Among its localities we may enumerate Scarborough 

 (Bean) ; Northumberland (Alder) ; at both which places 

 it is rare; Weymouth (S. H.); Poole (Pulteney) ; Ex- 

 mouth (Clark) ; Torbay (S. H.) ; Falmouth (Jeff, cab.) ; 

 West bay of Portland in fifteen fathoms, dead (M'Andrew 

 and E. F.) ; Tenby (Lyons) ; Pwlheli (M'Andrew) ; near 

 Milford Haven (Lyons); " Bantry, Cork, Youghal"" 



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