In addition to the Common Limpet (Patella vulgata) we have the Smooth Limpet (Patella pellucida), which must be sought at low-water on the borders of the laminarian zone. It feeds upon the Great Oar-weed, and a peculiar variation will be found between the specimens feeding on the smooth flat fronds and those feeding on the great stems. The shell of the first is coloured a pale brown, pellucid as its specific name suggests, the apex set very far forwards, and from it there start backwards from three to six exceedingly fine radiating lines of a dazzling brilliant blue. The specimens that live upon the Oar-weed’s stems look entirely different, for the shell becomes thickened, and consequently much more opaque, and its shape alters to enable it to sit close on a rounded surface. It was formerly considered a distinct species, and was named Patella lævis. So, too, the little Tortoise-shell Limpet (Acmæa testudinalis), changes its form when feeding upon the leaves of the Grass-wrack (Zostera marina), and has then had the name of Acmæa alvea bestowed upon it.

Among the weeds on the rocks we are sure to find the Netted Dog-whelk (Nassa reticulata), with a rather dirty-looking shell. It is covered with broad grooves crossed by fine lines at right angles, producing the appearance of network, which gives it the distinctive name, netted. Its scientific name also is suggested by the same appearance, for Nassa is Latin for a special kind of fishing-net. Like the Purple, the Dog-whelk is carnivorous. There is a prettier species, with a thick lip, called Nassa incrassata.

The true Whelk (Buccinum undatum) only comes within our province in the shape of empty shells cast up on the beach, for its range is from low-water to a hundred fathoms. In deep water it is very plentiful, and fishermen who want it for bait, let down baskets containing pieces of fish, which attract a large number to their doom. Their remarkable clusters of egg-nests are frequently washed ashore with seaweeds; each capsule in the bunch contains about half-a-dozen eggs. The shell of the Whelk, rubbed down on a smooth slab of stone, affords an admirable vertical section illustrating the structure of gasteropods.

The Red Whelk is the Fusus antiquus, so-called because it abounds in a fossil condition in the Red Crag of Essex, where also occurs a reversed form—that is, with the spire coiled the contrary way, and hence called Fusus contrarius. In Scotland it is the Buckie, or the Roaring Buckie, for this is the shell in which the roar of the sea resides. It is more esteemed than the Common Whelk as food by the poorer population of Scotland. It occurs, like Buccinum, from low-water to a hundred fathoms.

There is a fairly common shell, similar in size and general form to the Purple, but bristling all over with flattened recurved hooks, in clusters of threes. It is generally known as the Sting-winkle (Murex erinaceus), one of a genus from which the celebrated purple dye of ancient Tyre was obtained. Its familiar name it owes to its sharing in the hideous crime of destroying edible species for the sole purpose of gratifying its own base appetite. The fishermen have actually noticed it in the act, and seeing the peculiar boring apparatus at work, have thought this a sting. It is far worse than that, for a sting may be survived, but no mollusk, I believe, gets over the attack of the boring tongue, which changes its function when the boring is finished, and becomes an instrument for tearing and masticating its victim’s flesh.

The exotic representatives of the great Cone-family of shells are familiar and admired objects in collections as well as on nick-nack tables in the drawing-room. We have no native species of the genus Conus but we have a number of representatives of the family in the Pleurotomas and Mangelias, though they do not approach very closely to the typical form of a Cone-shell, with which we commonly associate the spotted Cone (Conus marmoreus) of Chinese seas. The Seven-ribbed Conelet (Mangelia septangularis) is like a tiny Buckie-shell—it is but half an inch long—with bold longitudinal ribs, of which you can count seven in one revolution of the shell. The shell is thick, of a dull pinkish hue, and unprovided with an operculum. The outer lip is notched where it joins the previous whorl. There are several British species.

One of the most charming of our native shells is the little Cowry (Cypræa europea), which is so plentiful on most of our shores. Most of us who have visited the sea-shore in childhood have had the delight of hunting for this shell, empty and clean, among the ingredients of a fine beach; but probably some of those who are most familiar with it as an empty shell would scarcely recognise it for the same species if they saw the living Cowry gliding along with his shell on his back. He carries a pair of tentacles, with eyes at their base, and the long curved tubular tongue ready for service; but the most singular feature is that his mantle is used not merely to clothe the delicate body, but a portion of it comes outside, and closely wraps the greater part of the shell. In its younger days it had not its present beautifully arched lip, which almost closes up the doorway of the shell, and leaves but a narrow slit, delicately denticulated, to allow the foot and mantle to pass through. Before maturity it had a wide mouth, with a sharp thin edge to the outer lip, but that, you see, has now grown over towards the inner lip. The colour of the shell may be described as a flesh-tint on the upper surface, varying in intensity to both lighter and darker. Many specimens bear on the crown of the shell three ill-defined blotches of a very dark brown. The under surface is white. The whole shell is ornamented by very regularly disposed transverse ribs, which are rounded and polished.

There are several other cowry-like shells to be found generally distributed, but by no means so plentifully on our coasts. One of these is the Smooth Margin-shell (Erato lævis), smaller than the Cowry, and with the lip curved outward, instead of inward as in the Cowry: it has thus an external margin, whence the name. It is white and exquisitely smooth. The animal is very similar to Cypræa, and it envelops its shell in the same fashion. Of similar habit is the Poached Egg (Ovula patula), though the shell is very different. The mouth of the shell gapes widely, and the lip is thin and sharp. Its colour is white with a pink tinge, and its appearance is so suggestive of its name that there is little likelihood of mis-identification. It is a South Coast form.

A solid-looking shell, with a highly-polished surface, over which three lines of arrow-heads are chasing each other, a perforation of the shell just outside the inner lip, a fairly wide mouth, closed when at rest by an operculum: these are the principal features of the Necklace Natica, so-called because it deposits a large number of eggs, so agglutinated into a broad spiral band, that the whole has been likened to a necklace. So it is called Natica monilifera, and monilifera means necklace-bearing. The animal is an odd creature, whose mantle laps partly over the shell, and the large foot is furnished in front with a broad fold, which is turned back as a protection to the head. It is herbivorous, and crops the seaweeds on sandy and gravelly shores, from low-water to about ninety fathoms.

“This is clearly a good case of protective colouring. Presumably the Lamellaria escapes the observation of its enemies through being mistaken for a part of the Leptoclinum colony; and the Leptoclinum being crowded like a sponge with minute sharp-pointed spicules is, I suppose, avoided as inedible (if not actually noxious through some peculiar smell or taste) by carnivorous animals which might devour such things as the soft unprotected mollusc. But the presence of the spicules evidently does not protect the Leptoclinum from Lamellaria, so that we have, if the above interpretation is correct, the curious result that the Lamellaria profits by a protective characteristic of the Leptoclinum for which it has itself no respect, or to put it another way, the Leptoclinum is protected against enemies to some extent for the benefit of the Lamellaria which preys upon its vitals.”

Since the publication of Prof. Herdman’s note, I have frequently found Lamellaria on the undersides of large stones at low-water on the Cornish coast. I have always found it on Leptoclinum gelatinosum, and can quite endorse his remark as to the difficulty of distinguishing it. On one occasion I found no less than four specimens feeding upon one patch of the ascidians, and pointed them out to a friend, who, however, failed to see them until they were absolutely touched by my finger. The shell is exceedingly delicate, and in the hands of most persons would be hopelessly ruined at the first touch. The ordinary methods adopted by conchologists for getting the animal from the shell will not answer in this case; but I have a plan which succeeds admirably. I give a specimen of Lamellaria to an anemone of refined tastes, who will deal with it carefully. Bunodes verrucosa is my favourite assistant, and he returns the shell clean and sound in a day or two.

There are several species of Spire-shells (Rissoa) to be found feeding in great numbers on Grass-wrack and Sea lettuce, and we shall also find the empty shells in the sand. There are, however, other forms that may be confused with them and with each other, that are very plentiful in sand. These are the comparatively large Turret-shell (Turritella communis), which is ornamented with spiral ridges, each one running continuously from the apex to the mouth. In the Ruddy Pyramid (Chemnitzia rufescens), which is much smaller, but of similar form, the ridges run across instead of along the whorls, whilst in the Horn-shell (Cerithium reticulatum), a similar effect is obtained by several rows of very regularly arranged round dots in high relief. A more distinct member of the family of Cerites is to be found in the well-known Pelican’s-foot or Spout-shell (Aporrhais pes-pelicani), in which the whorls are boldly tuberculated. When the shell has grown to its full length, its annual stages of growth take a somewhat different direction, and spread out in expansive lobes and corrugations until it bears a fanciful resemblance in outline to the foot of the pelican. The shell is about an inch and a half in length, and very thick. The animal is carnivorous.

Delicate specimens of the well-known Wentletraps (Scalaria) may be found among fine sands. They are readily known by their dazzling whiteness, the nearly round and flat-lipped mouth, and the bold curved ridges that stand out across the whorls like cogs on a wheel. To this genus belongs the Precious Wentletrap (S. pretiosa), from China, for a single specimen of which as much as forty guineas has been paid. This was in the days when shell-collecting without any scientific object in view was a mania with some wealthy people; just as we have had the tulip-mania, and now have the orchid-mania affecting persons who are impelled by fashion rather than a love of knowledge or the beautiful in Nature.

However we may be inclined to pass over the Periwinkle (Littorina littorea) as a species too common to need any attention, it is bound to thrust itself upon our vision at every turn among the rocks, where it swarms. It appears strange that whilst this species is so largely eaten by the poorer classes in towns as a “relish” for tea, the allied and almost equally common species, L. rudis, should be let severely alone. But the explanation is probably to be found in the fact that whereas littorea deposits her eggs in the ordinary way, rudis retains hers until they have hatched out. Now seeing that the Winkles of both species develop their hard stony shells before they hatch, it would be impossible to eat L. rudis without the great inconvenience of having these hard gritty infants damaging one’s teeth. The smaller red, or bright yellow shell, that may be found in abundance on the rocks and weeds between tide-marks, is Littorina littoralis.

The seeker for shells on a sandy shore must do as the children do—throw himself prone upon the beach, and hunt thoroughly, inch by inch, examining the topmost layer first, then lightly scraping it off and bringing fresh treasures to light. In this manner he will certainly turn up the exquisite little Pheasant shells (Phasianella pullus), that have the misfortune to be so small, or they would be greatly esteemed for their rich colouring. They are very smooth, and of a white or pale yellow hue, but so thickly covered with fine crimson lines that at first sight this appears to be the colour of the shell. These lines run parallel with each other, but with many curves, some flowing gently, others short and acute. These lines vary much in thickness throughout their length, here being very fine, there thickening gradually and thinning off again. The shells are less than a quarter of an inch in length, and the mouth is closed with an operculum. The animal has the peculiar habit of moving first one half, then the other, of its foot in progressing.

One of the handsomest of our common rock-shells is the so-called Common Top (Trochus zizyphinus), though it is scarcely as plentiful as the much smaller Grey Top (Trochus cinereus). It is pyramidal in form, with an almost flat, broad base; the mouth closed by a spiral, horny operculum. In some species there is an umbilicus, in others it is wanting. The animal has two small fringed lobes between the tentacles, and similarly fringed lappets to the neck. The sides, too, are lobed, and several tentacle-like processes are given off from them.

The Grey Top (T. cinereus) is variable in colour. Usually it is a dull yellowish grey, with inconspicuous dark zigzag marks upon it; sometimes the ground colour is pinkish-white, with decided pink markings, which present a checkered appearance. There is a deep and wide umbilicus. In Trochus zizyphinus there is no umbilicus, and in the large Painted Top (T. magus), again, there is a very wide one. This last-mentioned species lacks the smoothness of outline exhibited by the other two, its whorls being more boldly ridged at their junctions (suture). The animal has the head-lobes largely developed, and it is brilliantly and variously coloured; hence its name. The Tops are vegetable feeders.