BIVALVES AND CUTTLES. 281 



with longitudinal lines and delicately fringed at the tip. 

 The shell is small, at most an inch long, and some half-inch 

 broad. It is oblong and beautifully glossy and polished, 

 the surface being marked by fine longitudinal striae. The 

 inner margin is strongly notched, and the inside of the shell 

 is usually stained with violet. The colours of the outer 

 surface are varied, usually shades of violet, brown, or 

 yellow, but it is sometimes almost white. 



An even prettier and more delicate shell is the little 

 Tellina tenuis, which, thin and fragile as it is, is often 

 tossed up intact after a storm. The shell is often pure 

 rose-pink, sometimes pure white, sometimes yellow or 

 orange. It is so much flattened that one might fancy the 

 animal would hardly have room to live inside, and so thin 

 that it can hardly afford much protection. The ligament is 

 very thick and prominent, the teeth small. The shell is 

 oval and semi-transparent. There are various other species 

 of Tellina, some of them common but mostly small, and 

 not to be found in the living state. 



Another sub-order includes the Venus and carpet-shells, of 

 which there are a number of species. The species of Venus 

 are very numerous, and can be recognised by their triangular 

 or rounded shells with distinct concentric ribs. It may, 

 however, be sufficient if we name one species, common at all 

 seasons as a shell on the shore, and to be found living in 

 sandy places. This is Venus striatula, a small shell measur- 

 ing about an inch each way. The animal has fairly long 

 siphons united for the greater part of their length, a thick 

 foot slightly bent, and mantle-folds open in front. The 

 shell is pale-coloured, but usually marked by three bright- 

 coloured longitudinal rays of reddish tint, which cross the 

 strongly marked concentric ribs. A point of interest about 

 the animal is that it seems to be greatly relished as food by 

 some of the whelks, for most of the shells found on the 

 shore are perforated near the beak, showing that the whelk 

 has drilled a hole through it, as a preparation to the devour- 

 ing of the contained animal. 



Of the little carpet-shell (Tapes pullastra) we have already 

 spoken ; it occurs very commonly on the rocks in sandy and 

 muddy places. The shell is rhomboid in shape and solid in 

 texture; it is marked by very numerous close set bands 



