to mention will be those of Lamarck, when not otherwise distinguished.

Neritina virginea (fig. 182. a).- Is not this a fresh-water shell? Yet Dr. Turton describes it as found on the western coasts of Ireland. Will not Dr. Turton's shells, from their locality and diminutive size, prove another species?

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Valvata piscinalis (b).— Along with this species, of the usual magnitude, I have found dead shells, four lines in length (c), and several smaller ones of various sizes (d), agreeing pretty well with the species V. planórbis, V. ossirórbis, and V. minúta of Draparnaud, and which I have little doubt are all the young of the V. piscinàlis in different stages of growth, although Lamarck refers to them as distinct. Mr. Dillwyn is evidently wrong in considering this species to be the Túrbo thermalis of Linnæus. The latter author describes his shell to be only a little larger than a cabbage seed." The vague descriptions of authors often tend to confuse. Dr. Fleming, in the History of British Animals, just published, in his specific definition of this shell, characterises it as possessing "a large central cavity," but in his general description, a few lines lower, he says, "central cavity distinct, but not large."

α

Lymnæ a frágilis, Fleming (e). —This must be the Bulimus frágilis of Lamarck, who, it evidently appears, has arranged this shell among his Bùlimi, in consequence of not knowing the habitat. He states his specimen to have been received from Dr. Leach.

Lymnæ a detrita, Fleming (f). Does Lamarck include more than one species under his Bùlimus radiàtus; and, if so, is not this one?

Lymne'a ovata (g).-What I consider to be this shell occurs in tolerable abundance in this neighbourhood. My speci mens, several of them an inch in length, agree with the figures given by Draparnaud, but Lamarck describes his shell to be only 6 lines long. Is this the large variety of Hèlix putris mentioned in Dr. Turton's Conchological Dictionary? What is the Hèlix pùtris of Linnæus? Is it this shell, the Lymnæ a péregra, or the Succínea amphibia?

VOL. I. No. 5.

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G G

Planórbis nitidus (fig. 182. h). - Does not Lamarck include two species under this name, viz. the Naútilus lacústris (¿), and Hèlix fontana of English authors? The description and reference to Draparnaud evidently belong to the latter shell; the references to Muller and Gmelin probably to the former, but not possessing the works of either of the two last-mentioned authors, I cannot determine.

Succinea amphibia (fig. 183. k).—Is this the Hèlix pùtris, or H. limosa of Linnæus? Cuvier, Lamarck, and Fleming say the former. But it is worthy of observation, that Linnæus, in his Systema Naturæ, refers to Gualter t. 5. f. H. for a figure of the latter shell, which figure is undoubtedly the Succínea amphíbia. The habitat given by him for the H. limòsa also accords better than that of the H. pùtris, with the shell in question. Did Linnæus possess a cabinet of the shells described by him in the Syst. Nat.; and, if so, did it, with his herbarium, get into the hands of the late lamented President of the Linnæan Society? Many difficulties might be cleared up on a reference to the shells, if in existence.

Clausília ventricosa, Drap. (1).—I consider this to be the shell described by English authors under the name of Túrbo biplicàtus. Dr. Fleming is of opinion, however, that Draparnaud has not described our shell. The two specimens in my possesions, and which I received from that excellent naturalist, Mr. R. Leyland of Halifax, accord well with Draparnaud's figure, and very nearly so with his description. Clausilia sólida, Drap. (m). Is this the Túrbo labiatus of English authors; and, if not, has the latter shell been described by any of the Continental writers, and under what name? I have not seen the shell.

Pupa britannica (n).—I have ventured to give this name to the Turbo trìdens of English authors, as the shell appears to be unknown among the Continental conchologists. It is not the Pupa tridens of Lamarck, and many of Dillwyn's synonymes are erroneous. Dr. Fleming places this species in the new genus Azèca, but appears dissatisfied with its station, and suspects it may eventually associate with his genus Carychium; in this, however, he is incorrect, since the animal, in the latter genus, possesses only two tentacuła, whilst the

Pupa britannica, as I have lately ascertained from living specimens, is furnished with four. The shell in question in the Lamarckian arrangement agrees best with the genus Pùpa, and the specific appellation is untenable, and another necessary, not only to distinguish it from the P. trìdens of Lamarck, but to correct an error with regard to the number of its teeth, which, in reality, are five. The appellation P. quinquedentata might have served, if some other species of this genus were not also furnished with five teeth. As there is already a Pùpa germánica, the specific name I have adopted appears to be as little exceptionable as any other, particularly if the shell be not really found out of this country. Should the Baron de Ferussac have noticed this shell by any other name, of course it will have the preference, as I am inimical to useless changes in nomenclature. There is no necessity for the adoption of the new-fangled genus Azèca. If Dr. Fleming considered he would be doing nature too much violence by placing this shell amongst his Pùpæ, he might have found an unobjectionable receptacle in the genus Chondrus, established by Baron Cuvier.

Pupa muscòrum. This is much confused. There are three shells described by conchologists under this name and that of Turbo muscòrum (fig. 183. o p q), all referring to Linnæus; and Donovan has figured a fourth species, as his Túrbo muscòrum (fig. 183. r).

Hèlix fusca, Turton, &c. (fig. 184. s). - Dr. Fleming suspects this to be the H. fúlva of Muller. The English shell is about half an inch in diameter, whilst the figure of that of Muller, given by Draparnaud, if I recollect rightly, is little more than a line.

Hèlix sylvática (fig. 184. t).—Is this British, and under what name has it been described? Is it the H. lucòrum of Dillwyn? Hèlix carthusianella (u). - I suspect this to be the Helix cantiàna of authors (v), the H. pállida of Donovan.

Helix cellària (w), nítida(x). Are these really distinct, or only the same shell in different stages of growth? Helix rufescens (y), Eng. auth. This common shell seems to be extremely ill understood. Is it referable to none of the numerous species described and figured by Draparnaud? Circumstances which have tended to render it more confused, are, that English authors have followed each other in describing the immature shell to be hairy, and that the figure given by Donovan, plate 151. f. 1., under the name of Hèlix hispida, is the H. rufescens in a young state (z). The two shells are doubtless specifically distinct; the H. ruféscens is keeled on the margin of the outer whorls and smooth, the other rounded and hispid. It has been imagined that these hispid shells lose their hairiness, and add a keeled whorl to their former rounded ones, on arriving at maturity. This is fallacious. By carefully removing the whorls of the H. ruféscens with a knife, it will easily be perceived that they are all keeled. I possess specimens from one to seven lines in diameter. The small ones are as distinctly keeled as the large. Observations of a similar nature have also been made by my friend, Mr. William Helm, a most successful and industrious collector here.

Hèlix hispida (aa). -This species I take to be the hairy one, confounded with the Hèlix rufescens. Does the H. túrturum of Gmelin belong to this or the last?

Helix sericea, Drap. (bb).-I consider this the shell called Hèlix hispida by Turton, and several other English writers. A'nodon intermedius.

(fig. 185.)-Is this an English species? The Mytilus stagnàlis, dentatus and avonénsis of Turton, &c., are ill understood; and some of them may, if really distinct from the A. cycnèus and anatinus, be referable to this species.

The number of indigenous land and fresh-water species, appears to be between 100 and 120, of which I and one or two other friends have collected about 60 species in this neighbourhood. Several described as rare, occur in tolerable abundance, whilst others which are represented as plentiful, have hitherto eluded our researches. I fear that a list of those discovered would be too unimportant to trouble you with, but should you be of a contrary opinion, it will be at your service.

In conclusion, I would just observe, that the making of mutual exchanges of specimens, from different localities, appears well calculated to further the objects of naturalists, and more particularly of those, situated like myself, whose avocations require an almost uninterrupted attendance on the spot. I have the honour to be, &c.

Butler Street, Preston, June 14. 1828,

JOSEPH KENYON.

ART. VI. An Introductory View of the Linnean System of Plants. By Miss KENT, Authoress of Flora Doméstica, Sylvan Sketches, &c.

WITH our last letter we concluded the third class, Triándria; before we proceed to the next, it will be well to give some preliminary explanation of the different modes of inflorescence. Plants bear their blossoms in as many different fashions as a lady wears her jewels; which fashions are called the modes of inflorescence. Some flowers grow on the stem, some on the leaves; some opposite the leaves, some in their axils; some laterally, some terminally; some singly, some in pairs, and others in clusters; and of these clusters there are

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various forms. The flowers of the dead-nettle grow in rings round the stem (fig. 186.): these rings are termed whirls, or whorls; and the flowers are either sessile (sitting close upon the stem) or have very short stalks. There is a plant now very common in gardens, called the Búddlea globosa, which affords a good specimen

of the cluster called a head (fig. 187.): the flowers are collected into a round ball, by growing very near together upon one common stalk; they are mostly sessile, but have sometimes each a short stalk, by which it is attached to the common one.. Lavender flowers grow in spikes (fig. 188. a): the spike has a number of flowers, either sessile or on very short stalks, laterally attached to the main flower stalk. A bunch of currants exhibits the raceme: it differs

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