mostly found in spots where sand and mud are mixed together. They are mostly remarkable for their beautiful colours, presenting in this respect a bold contrast to the dull whites and browns of the preceding shells. The animal always has very long and slender siphons, and a tolerably powerful foot.
Our first example is seen at Plate III., fig. 6, and is known by the popular term of Sunset-shell (Psammobia tellinella), because the diverging rays which traverse the shell are fancifully thought to resemble the beautiful beams of the setting sun as they are thrown upon the evening clouds. These rays are generally pink, and in a specimen now before me they are bright red on a pale yellow ground, but are much broken up and dissimilar on the opposite valves. The figure represents the shell of its natural dimensions. It is widely spread, but is seldom if ever taken without the help of the dredge, though the separate valves are sometimes cast on the shore.
At fig. 9 is shown the shell of another species of the same genus, which we may call the Striped Sunset-shell (Psammobia Ferroensis). It is a larger and handsomer species than the last, being nearly two inches in length when adult, and having the peculiar markings very distinct. The remarkable diverging teeth of this genus are seen at page 25, fig. 15.
We now come to the typical shells of this group, which belong to the genus Tellina. This is a very large genus, at least two hundred existing species being known in different parts of the world, of which some ten or eleven are acknowledged as British. The Tellen shells are inhabitants of the sand and mud, and sometimes bury themselves to a considerable depth. One of the best British examples is the Blunt Tellen (Tellina crassa), a figure of which may be seen at Plate III., fig. 8. This is a pretty shell, and rather larger than the generality of its kind,
d 2
