But the most remarkable species of all is assuredly _Spondylus regius_ (PL. XV. Fig. I.). This species is a native of the Indian Ocean, and there scarcely exist three fragments of this rare shell in the museums of Europe. M. Chenu relates in one of his books an anecdote which would prove--if any proof were necessary--how far the desire of a collector to obtain possession of some rare and costly specimen will carry him in order to attain his object. "M. R----," says M. Chenu, "was Professor of Botany to the Faculty of Paris, and was, as some times happens, more learned than rich; he wished, on the invitation of a stranger, to purchase one of these shells at a very high price, which might be from 3000 to 6000 francs; the bargain was made, and the price agreed upon; it was only necessary to pay. The money in the professor's hands made only a small part of the sum the merchant was to receive for his shell, and he would not part with it without payment. M. R----, now consulting his desire to possess the shell more than his weak resources, made up secretly a parcel of his scanty plate, and went out to sell it. Without consulting his wife he replaced his silver plate by coverings of tin, and ran to the merchant to secure his coveted Spondylus, which he believed to be _S. regius_. [Illustration: PLATE XV.--Spondylus. I. Spondylus regius. (Linn.) II. Spondylus imperialis. (Chemu.) III. Spondylus radians. (Lamarck.) IV. Spondylus avicularis. (Lamarck.) V. Spondylus crassisquama. (Lamarck.) VI. Spondylus gæderopus. (Linn.) ] "The hour of dinner arrived, and we may imagine the astonishment of Madame R----, who could not comprehend the strange metamorphosis of her plate. She delivered herself of a thousand painful conjectures on the subject. M. R----, on his part, returned home happy with his shell, which he had committed to the safe custody of a box placed in his coat pocket. But, as he approached the house, he paused, and began for the first time to think of the reception he might meet with. The reproaches which awaited him, however, were compensated when he thought of the treasure he carried home. Finally, he reached home, and Madame R----'s wrath was worthy of the occasion; the poor man was overwhelmed with the grief he had caused his wife; his courage altogether forsook him. He forgot his shell, and, in his trepidation, seated himself on a chair without the necessary adjustment of his garment. He was only reminded of his treasure by hearing the crushing sound of the broken box which contained it. Fortunately, the evil was not very great--two spines only of the shell were broken; but the good man's grief made so great an impression on Madame R----, that she no longer thought of her own loss, but directed all her efforts to console the simple-minded philosopher."