4 solenid^:. 



two-thirds cover the ventral or front part of the shell, and 

 radiate from the beak, the rest occupying the whole of the 

 posterior side, and diverging- from an angle formed by a junc- 

 tion with the first-mentioned set of striae ; this angle varies 

 from acute to obtuse, according to the number of striae ; the 

 anterior side is not thus striated ; the surface is also covered 

 with minute and crowded longitudinal stria) resembling those 

 observable in species of Psammobia : colour pale yellowish- 

 white : epidermis like oil-skin, yellowish with a brown tint in 

 aged specimens : margins slightly incurved in front, obliquely 

 truncated with a rounded contour at each end, nearly straight 

 behind and parallel with the front, except in the middle, where 

 the beak forms a projection equal to the indentation on the 

 opposite side : beaks pointed and nearly straight : ligament 

 chrysalis- shaped, prominent, dark horncolour : hinge-line 

 straight : hinge-plate thick and strong, reflected over the 

 ligament and abruptly truncated at the posterior end : hinge 

 supported by a strong oblique shelf-like rib : teeth, in the right 

 valve two blunt cardinals curving upwards from below the 

 beak, the posterior being much larger than the other ; the 

 left valve has a similar cardinal on the anterior side, besides a 

 short, triangular and oblique lateral on the posterior side : 

 inside chalky- white, with a slightly nacreous gloss in some 

 parts, incipient pearls being occasionally formed on the 

 inner edge of the mantle ; margin blunt : pallial sear well 

 defined ; sinus oblong, and extending two-thirds across the 

 transverse diameter of the shell : muscrdar scars distinct ; an- 

 terior irregularly pear-shaped, posterior triangularly oval. 

 L. 0-9. B.l-9. 



Var. oblonga. Shell narrower in proportion to its breadth. 



Habitat : In sand, between low-water mark at spring 

 tides (Lukis), and various depths seawards, from 20 

 to 85 fathoms, on different parts of the coast from the 

 Shetland to the Channel Isles, but local ; more common 

 in Bantry Bay than elsewhere. Var. 1. Guernsey 

 (Lukis) • Polkernow Cove, Cornwall (Miss Lavars) ; 

 Shetland (Barlee) . Believing it to be the Solen multi- 

 striatus of Scacchi, I find it recorded as a fossil from the 

 neighbourhood of Antwerp, and from Gravina in Apulia. 

 Lamarck and Brocchi appear to have mistaken a white 



