We cannot for a moment hesitate to believe that in announcing to our readers the introduction of the Pink, or Roseate Imperial Sun Trochus: the significant appellation under which the present rarity has been for many years distinguished, we shall awaken the attention of every Conchologist and amateur of the science. The shell so named, formerly constituted an object, no less conspicuous than beautiful, among the Conchological productions treasured together in the once celebrated Leverian Museum. And, as we possessed, through the immediate favour of the proprietor of that Museum, John Parkinson, Esq. an unreserved access to every article in the Museum, for the purpose of delineating the figures, or taking the descriptions of whatever we conceived worthy of such observation, it will be naturally imagined the Pink, or Roseate Imperial Sun Trochus, would be esteemed of too much importance to escape our very particular attention. The dispersion of that once celebrated Repository of Natural History has long since removed, and probably for ever, this exquisite rarity from the eye of public curiosity; nor indeed is its present destination correctly known; a circumstance, it is presumed, that cannot fail to enhance the value of a drawing, which we have every reason for believing to be the only memorial of this kind the pencil of the Arts have consecrated to the commemoration of the shell: the only figure, we are assured, the proprietor ever permitted to be taken from it.—Having premised so far, it will not be deemed superfluous to add, that the outline of the specimen is precisely a fac-simile of the shell itself, having been traced round its contour while lying upon the paper, and being afterwards finished in colours upon the outlines so struck, with every attention an object so estimable was presumed to merit.
The history of this curious variety of the Imperial Sun Trochus is altogether interesting, and deserves explicit mention; it is one among the number of those rare shells which were discovered by that distinguished navigator, Captain Cook, in his voyage round the world. It was fished up in the Straits that divide the Island of New Zealand, now distinguished after him, by the appellation of Cook’s Straits. Upon the return of Captain Cook to England, he presented Sir Ashton Lever, among other articles of great curiosity, with this particular shell, the only one of its kind he had found. The Imperial Sun Trochus, of an olivaceous violet hue, the shell which constitutes the type of this species, though very scarce, occurred occasionally, but this Pink variety only in the solitary instance before adverted to: it was drawn up, adhering to the cable of the ship, from the depth, as it appeared, of sixty fathoms water.[[7]]
In the general computation of the value of the various articles in the Museum of the late Sir Ashton Lever, submitted to government, previous to the grant of the Lottery which transferred the possession of that Museum from its original founder to the hands of Mr. Parkinson, this shell was estimated at the value of one hundred guineas: and as this valuation was arbitrary, that sum was considered as the worth of the shell while it remained in the Museum. At the final dissolution of this Museum, which took place in the months of May, June, and July of the year 1806, this shell, like the rest, was submitted to the chance of taste or caprice: it was sold on the last day of the sale, for the sum of twenty three guineas, an amount considerably below its former valuation, but sufficient, nevertheless, to shew that its attractions were still great in the mind of the connoisseur.
The purchaser of this shell was at that time unknown, subsequently, however, the specimen appeared among the property sold at the residence of the Duke de Bourbon, immediately after the departure of that noblemen for France, in the beginning of the year 1815.[[8]] Dr. Leach has since that time informed us that he had given instructions for the purchase of this shell for the British Museum: the shell does not, however, appear in that collection, and the lamented illness of our ingenious friend, is likely, for the present, to preclude all further inquiry respecting its final destination.
It does not appear that this very curious variety of the Imperial Sun Trochus is known in any of the continental cabinets: the olivaceous kind, which as before observed, is to be regarded as the type of the species, though esteemed scarce, is to be found in every continental cabinet of importance. Indeed, the olive kind maintained a very high reputation and price for many years after the time of Captain Cook, who brought several of them to England; from whence those continental cabinets were, in the first instances, supplied. Since that time the same seas have been attentively explored by Admiral Bligh, in the ships of his Majesty under his command; and through his researches, this shell, which was once considered of such unusual rarity, has become rather more common. The Pink, or Roseate variety, the immediate object of our present illustration, has hitherto, however, escaped all research, and it still remains as it was esteemed originally, after a lapse of nearly fifty years, not merely scarce, but perfectly unique.
An ingenious French writer of the present day, Denys de Montfort, in describing the olivaceous kind, the type, as before remarked, of the present species, has paid an appropriate tribute of applause to the memory of its original discoverers. “It is,” says he, “to the Voyages of the celebrated Captain Cook, and to the researches of the indefatigable Naturalists who accompanied him, that we owe the knowledge of this fine and magnificent shell.” “This shell,” he adds, “appears to be exposed to such a swarm of aggressors, that his Mollusca (or animal) must lead a life of activity and war: his shelly covering is ploughed, or furrowed, and pierced by a host of enemies, and he must necessarily employ almost the whole of life in repressing their attacks, and in constantly repairing the breaches and perforations they occasion, by the exudation of the nacrous molecules, or fluid, with which nature has furnished him, in order to preserve the inner coating of his shelly habitation entire.” Such is really the appearance of this shell in general; we have seen it so completely despoiled of its exterior coating by these attacks, as to render it impossible to form any tolerable conception of the shell when perfect; even an approach towards perfection in its outer coating is very rare. The most complete of its kind in the collection of the late Admiral Bligh, and probably selected as the best he ever met with, was perfect in this respect than might be expected. By one of those rare chances which sometimes happen, the Roseate variety, which forms the subject of our present illustration, had entirely escaped every accident of this nature, insomuch, that its figure may be regarded as that of a very perfect shell.
The earliest figures of the common, or olivaceous kind, occurs in the work of Chemnitz, and among the plates of Martin. Gmelin quotes the former, and describes the shell under the name of Trochus Imperialis. It is truly a Trochus of the Linnæan classification, but not, it appears, of any later writer, excepting those of the Linnæan school. Sometimes it has been generically classed as a species of Solarium, a name assigned by Lamarck to the Trochi possessing the character of the Linnæan Trochus Perspectivus, and which he renders into his own language as a generical epithet, by the name Cadran (Sun dial). To accord exactly with the genus Solarium, as laid down by Lamarck himself, the general figure of the shell should be that of a depressed cone, having at the base an umblical opening, crenulated upon the inner edge of all the spires; as may be perceived in looking down the umbilical opening of Trochus perspectivus; and finally, the opening of the mouth should be almost quadrangular. This is the character of Solarium, as proposed by Lamarck, and which does not agree exactly with the shell before us.[[9]] Denys de Montfort constitutes another genus of this shell, which he denominates Imperator (Conchyliologie Systematique T. 2. p. 199) in the French, L’Empereur. The olivaceous kind he calls Imperator aureolatus, l’Empereur couronné. The character of this new genus, Imperator, consists in the shell having a regular spire: in being imbricated, or covered with scales, like tiling upon the roof of a house: the carina of the whorls armed; the armament, for example, in the shell before us, consisting of a kind of frieze or curled foliage-like plates which succeed each other with great regularity: it has an umbilicus, which, in the present shell is large and deep; the mouth of the shell angular and entire; pillar lip spreading somewhat like a fan; and the exterior lip cut off. We have deemed it requisite to advert to these new genera, but as the shell itself is so clearly a Trochus, we have not thought it necessary to remove it from the place in the Linnæan System to which Gmelin had assigned.
12
London. Published as the Act directs, by E. Donovan & Mess.rs Simpkins & Marshall July 1, 1822.