SOLEN. RAZOR-SHELL. 159 



end and rounded at the other, covered with an olive-brown 

 skin which has variously disposed chesnut marks, beneath 

 which it is greyish-white with purplish streaks : valves a 

 little convex and rounded, divided diagonally into two very 

 acute triangles, the anterior triangle transversely striate, 

 the posterior one with longitudinal striae and purplish, 

 bands : down the back from the hinge is a flattish space in 

 each valve, suddenly sloping and forming a kind of ridge, 

 and giving the back margin a keel-like appearance ; inside 

 white, with a single tooth and lateral rib in one valve, 

 locking between two teeth in the other valve, which has 

 also an inclined lateral laminar rib : length from margin to 

 margin an inch ; breadth from one open end to the other 

 seven or eight inches. 



Variety. A little curved, like S. Ensis, but is distin- 

 guished by the teeth. Lister, pi. 413, lower fig. 

 On most sandy shores, v. v. 



2. Solen Novacula. Whetstone Razor-shell. 

 Montagu, p. 47. 



Shell straight, slender, in every respect resembling the 

 last, except in the structure of the hinge, which has one 

 strong curved blunt tooth in each valve, turning contrary 

 ways and locking into each other, and without the lateral 

 laminar ribs. 



On the sandy shores near Laugharne in Carmarthenshire : 

 we have also found shells which answer this description, 

 but of much smaller size, in Dublin bay : and considering 

 the great fragility of the teeth of this family, we have some 

 doubt of its specific identity, v. m. 



3. Solen Vagina. Sheath Razor-shell. 



Lister, pi. 410. f. 256, and pi. 1056. f. 5 Pennant* 

 pi. 49. f. 1 Wood, pi. 27. f. I Dorset Cat. pi. 4. f. 8. 



Solen marginatus. Donovan, pi. 110. 



Shell straight, slender, covered with an orange-yellow 

 skin which is often marked with deep brown blotches, and 

 sometimes extends as much as half an inch beyond the 

 margin at the end opposite the hinge, under which it is of 

 a pale orange yellow, very faintly divided diagonally and 

 Striate like S. Siliqua, but without the ridge and furrow 

 p 2 running 



