VENERUPIS. 87 



to the anterior end, so that the posterior dorsal margin occupies 

 nearly one side of a parallelogram : beaks small, inflected, and 

 inclining considerably to the anterior side : ligament yellowish- 

 brown or homcolour, contained in a groove or excavation 

 with shelving sides, which extends for some distance from the 

 beaks : hinge-line obtuse-angled : hinge-plate thick and broad : 

 teeth erect, placed on the anterior dorsal line, the outermost 

 and innermost diverging ; in the right valve 3, of which the 

 outside one is much smaller than the other two, and these are 

 cloven ; in the left valve are also 3 similarly arranged, the 

 innermost being the smallest : inside porcellanous, often par- 

 tially stained with reddish-brown, particularly the hinge-plate 

 and posterior side : pallia! scar uneven, with a tongue-shaped 

 sinus : muscular scars deep ; anterior roundish, posterior oval 

 and situate close to the margin at the lower angle. L. Oo. 

 B. 1. 



Habitat : Laminarian zone on the coasts of Dorset, 

 Devon, Cornwall, Glamorgan, Pembroke, and Ireland 

 (west, sonth, and east). Red Crag (S.Wood); and 

 Philippi has recorded it from the South-Italian tertiaries. 

 It has not been noticed in Scotland or further north; 

 its southern distribution extends from Brittany to the 

 Adriatic, Black Sea, and yEgean, both sides of the 

 Mediterranean, and the Canary Isles, at depths ranging 

 from the shore to 20 f. 



It is attached by a byssns to gneissic rocks in Con- 

 nemara (Parran), and to the roots of Laminar i a bulhosa 

 in the west of Ireland (Harvey) ; it occupies holes made 

 by Saxicava rugosa in new-red sandstone at Exmouth 

 (Clark), in limestone at Tenby (J. G. J.), and Cannes 

 (Mace) ; and it inhabits crevices of rocks (but never 

 perforates them) on the coast of Sicily (Philippi) . The 

 shell being frequently distorted shows that the Venerupis 

 is not a borer, but accommodates itself to any place of 

 shelter : when thus enclosed it is occasionally incrusted 

 with nullipore and Spirorbis granulatus. The very 

 young are square, and the fry nearly circular. In perfect 



