Genus Spirorbis.

A stroller by the sea side, searching for shells or algae, is sure to meet with Sea weeds more or less thickly covered with little white shells, coiled up and attached firmly by one side to the weed. Sometimes they are so abundant that large fronds may have as many as a hundred on a square inch. If taken out of the sea while alive, and examined under a microscope, there may be seen to extend from the mouths of their tubes little conical buttons mounted on stalks, which are the stoppers or lids that close the orifices of their dwellings. These are followed by a group of little filaments, the gills of the animal, and amidst them is the simple suctorial mouth. These organs are slowly extended, but very rapidly withdrawn when the animal is alarmed by any agitation of the water or the vessel in which it is contained. If the animal is extracted from its tube it will be found to be a little jointed worm terminating in a point, and having at its sides minute hooks and bristles for enabling it to hold fast by the sides of its habitation and to ascend and descend at pleasure.

The species most commonly found on the shores of the gulf of St. Lawrence is the Spirorbis spirillum-Serpula spirillum of Linnæus. It is regularly spiral, with smooth rounded whorls, not enlarging rapidly nor much flattened at the lower side, but sometimes rising nearly into an erect position toward the mouth. Its favourite residence is on the fuci in shallow water. It is found on both sides of the Atlantic and as far north as Greenland.

On sea weeds and zoophytes from somewhat deeper water, we may often observe another species, smaller and more delicate in texture than S. spirillum, coiled less closely, and in the opposite way, or from right to left when the aperture of the shell is held from the observer. This is the Spirorbis sinistrorsa. It is not noted by Fabricius as a Greenland shell, but is found on zoophytes at Gaspé, and abounds on sea weed in deep water off the coast of Maine. This and the previous species are the only ones that an observer who confines his attention to the sea weeds of the shore may chance to meet with; but dredging in deep water will procure the following species.

Spirorbis nautiloides, the Serpula spirorbis of Linnæus, is of the same size with S. Spirillum, but is thicker, less smooth, transversely wrinkled, and more flattened at the base, so that when removed from its attachment it appears like a shell split into two equal halves. Its whorls also are more closely united and increase

in diameter more rapidly, so that there is a deep and narrow umbilical cavity in the centre. It is found both on stones and sea weeds in deep water. This is at least what I take to be the true Serpula spirorbis of Linnæ us and Fabricius, though more recently some confusion between this shell and S. spirillum seems to have arisen. It was found by Fabricius in Greenland. I have it in a collection made in Labrador by Mr. Carpenter, missionary of the Canada Foreign Missionary Society, and Dr. Gould has obtained it on the American coast. I have it also on stones from the Banks of Newfoundland.

When old, this shell forms a few semi-erect turns, so as to cover up the previous whorls and the umbilicus, and terminates in a thick and slightly expanded mouth, sometimes as much as half a line in width. So completely does the shell in this condition. differ from its immature state, that but for the appearances seen in sliced or broken specimens, I should have regarded it as a distinct species. A change of a somewhat similar character, though less marked, occurs in S. cancellata, and is represented in the figure of that species given below. Similar changes, though with differences in details, occur in S. vitrea and S. porrecta.

Spirorbis carinata (Mont.) is a deep water species, closely allied to S. nautiloides, if not a variety of it. It is distinguished by a keel or ridge running along the whorls, nearer the inner than the outer edge. In some old shells a second ridge appears, and then the shell very closely resembles S. quadrangularis of Stimpson. Young shells, on the other hand, are not distinguishable from those of the S. nautiloides. This species is not noted by Fabricius as a Greenland shell. It abounds in the collections of Mr. Bell of the Geological Survey, and in my own from Gaspé, where it occurred in deep water, attached to dead shells and stones. It was found at Labrador by Mr. Carpenter. I also have it on a stone taken up from the Banks of Newfoundland by a fisherman's hook, and presented to me by A. Dickson, Esq.

Spirorbis vitrea is like S. sinistrorsa, a reversed species, but is thick, semi-transparent, and has the whorls closely crowded, and in adult shells turned up and somewhat narrowed and thickened at the mouth. A group of these shells looks like a number of small drops of glass that had fallen on a stone and cooled there. Fabricius discovered this species in Greenland. It occurs in Mr. Bell's Gaspé collection, on the Banks of Newfoundland, and fossil

in the Pleistocene beds at Montreal and Beauport. It is noted by Stimpson as found in the Bay of Fundy.

Fig. 1.-Spirorbis cancellata. a nat. size; b magnified; c older shell less magnified; d, e side views.

Spirorbis cancellata is in point of ornament the prince of our Spirorbes. It is thick, regularly spiral when young, but with the mouth tending upward when old. Above, it has two, or, in old shells, three strong ridges revolving with the whorls, and giving it an elegant fluted appearance, and the outer side presents a furrow crossed by strong transverse bars, or in other shells appears as a regular slope with a series of depressed spaces at regular intervals. The whole appearance of this shell in a perfect specimen is very elegant, and as I have not been able to find a good figure of it in any work that I have consulted, I have attempted to represent it in the figures on this page. It is a reversed species. S. cancellata abounds in Mr. Bell's Gaspé collection. It is one of the species found by Fabricius in Greenland and named by him, but I am not aware that it has been met with since, until dredged by Mr. Bell in about 60 fathoms on the Gaspé coast, where it lives attached to the valves of dead shells. It is also in Mr. Carpenter's collection from Labrador.

Spirorbis granulata, (Muller) resembles that last described, but wants the ornament around the margin, having only two furrow and three sharp elevated ridges on the upper side, and it is not reversed. Fabricius, who found it in Greenland, states that its animal is yellow, with a white stopper on a short stalk, and six respiratory filaments. It occurs, though rarely, in Mr. Carpenter's

collection from Labrador, on stones and bryozoa, and was found by Stimpson at Grand Manan.

Spirorbis porrecta differs from the others in having only a few spiral turns and then boldly standing erect. It is thin, shining, and round in its tube, and from its habit of growth resembles a serpula; but the animal is that of a spirorbis. Fabricius very clearly describes it as follows. It occupies when contracted only a third part of the length of the shell, is smooth, flattened on the abdomen and attenuated posteriorly. Its stopper is extended on a stem and at its base are six soft, short, white, conical respiratory processes. At the base of these the body is white, plicated, and armed with golden setæ or bristles, extending forward. The rest of the body is blood red above, lighter on the sides and below, and its colour can be seen through the semi-transparent shell. This species occurs at Gaspé on Zoophytes, and is recorded by Stimpson as found at Grand Manan.

It thus appears that of these curious little spiral worm shells, the precise use of which in nature it would perhaps be difficult to point out, but which no doubt enjoy life after their fashion, and afford food to other animals, we have no less than seven or eight species in the gulf of St. Lawrence.

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Fig. 2.-Serpula (Vermilia) serrula? a nat. size; b anterior part magnified; c aperture magnified.

Genus Serpula.

The true serpulæ are neither abundant nor large in the Gulf of St. Lawrence, in so far as my observation extends. The most common species, found both in Labrador and Gaspé, is of small size, about th of an inch in diameter, wrinkled transversely and with a distinct and strongly denticulate keel on the back. It is adherent in its whole length, sometimes much and irregularly

bent, sometimes nearly straight. It corresponds exactly with the description of S. (Vermilia) serrula of Stimpson, from the Bay of Fundy. It also corresponds with the S. triquetra of Linnæus and Fabricius, except in its smaller size, and more delicate structure. In some specimens there is a structure which, so far as I am aware, has not been noticed in either of the above species. It consists of two lateral lobes, somewhat more than one-twentieth of an inch in length, attached to the sides of the anterior portion of the tube, and opening by narrow labiate mouths on each side of the principal orifice, so that there appear to be three orifices close together, the central one round, the lateral ones narrow and lunate. If the animal inhabiting this shell has the structure of protula, one may suppose that these lobes accommodate the lateral disk or expansion of the thorax. As they appear only in certain specimens, they may perhaps be connected with the function of reproduction, and be of the nature of ovi-capsules, or they may serve to enable a certain amount of respiration to proceed when the gills are retracted. It would be interesting to study the living animal with reference to these curious additions to its tube.

Serpula vermicularis is one of the shells which I have described in a former paper as found in the Pleistocene clay at Logan's Farm, but I have not seen it from the Gulf, nor is it noted by Fabricius. It is round, smooth, and tortuous.

Genus Pectinaria.

A shell, probably of this genus, made up of a single layer of grains of sand, is frequent on sandy shores. It is perhaps P. Groenlandica Grube, P. Belgica Lam., but I have not seen the animal.

The Serpula seminulum of Fabricius is a foraminiferous shell, the Miliolina seminulum described in my previous papers on the Pleistocene deposits. The S. stellaris of Fabricius is the Truncatulina lobata, also a foraminiferous shell, parasitic on shells and zoophytes, found in the Gulf of St. Lawrence and in the Pleistocene beds. Serpula contortuplicata, a common Atlantic species, is also noted by Fabricius, but has not been found in the Gulf. This industrious observer has also, under the genera Sabella, Nereis, and Tubularia, several species of tube-dwelling worms, which are perhaps identical with species of Sabella, Amphitrite, &c., described by the naturalists of the Tnited States, but which have not been observed in the Gulf of St. Lawrence.