Volume Iii Part 18 (1/2)

GENERIC CHARACTER.--See Pl. 96.

SPECIFIC CHARACTER.

_A. testa ovata, lata, cra.s.sa; margine cardinali subarcuato, extremitate utraque angulata alata; umbonibus prominentibus, apicibus retusis._

Sh.e.l.l oval, broad, thick; hinge margin subarcuated, the extremities winged and angulated; umbones prominent, the tips retuse.

It is only recently that travellers have directed their attention to the less attractive sh.e.l.ls of distant regions; and our cabinets now begin to be enriched by the numerous land and fresh-water species of those countries.

Among these new acquisitions, the fresh-water bivalves appear the most extraordinary in their formation, and the most numerous in species. Of the Anodons, it may be doubted whether the great Linnaeus was acquainted with more than three or four species; Lamarck enumerates fifteen, but a much greater number have pa.s.sed under my own examination.

The species now ill.u.s.trated is very peculiar; it is a strong, thick sh.e.l.l; in form resembling _Hyria corrugata_, Lamarck; having both extremities winged and compressed; the umbonial slope[6] elevated, and somewhat angulated; the umbones thick and prominent, but obtuse, or nearly truncate, at their apex; the outside of the sh.e.l.l of a dark gra.s.s-green colour, and nearly smooth, excepting at the posterior side, which is marked by sulcated striae following the lines of growth; the inside is opaque and whitish, with rich iridescent margins: the muscular impressions deep, and the hinge margin quite smooth.

I know of no other specimen than one in Mr. Dubois' collection, and am altogether unacquainted with its locality; although its _habit_ leads me to think it is from South America.

Pl. 168

[Ill.u.s.tration]

RAMPHASTOS ambiguus,

_Doubtful Toucan._

GENERIC CHARACTER.--See Pl. 45.

SPECIFIC CHARACTER.

_R. niger; jugulo flavo; mandibulae superioris parte superiore flava, transverse maculata, striga viridi oblique divisa; mandibula inferiore nigra._

Black; throat yellow, upper mandible black, the upper half yellow, with an oblique green stripe and transverse spots; the under mandible black.

The obscurity with which modern ornithologists have described these remarkable birds, would have induced me, long ago, to have attempted a more perfect account of all the species in this work; but as this might have been considered, by some, an infringement on the miscellaneous plan on which it was commenced, I feel obliged to confine myself only to their occasional ill.u.s.tration.

The species now selected is one I have never seen; but I have no doubt of its existence, and little of the accuracy of its delineation. I before alluded to several drawings of Toucans which had come to my hands, executed by an unknown artist: among them is a figure of that now published; with a note subjoined, stating it was drawn ”from the bird just dead.” The other drawings of the same artist represent several of the common species, and their accuracy is presumptive evidence that this also is represented correctly. The singular colouring of the bill at once separates it from all known species; and for its further history, we must trust to the exertions of those travellers, visiting South America, who may feel an interest in ill.u.s.trating these singular birds.

I more than once heard, when in Brazil, of a _Blue Toucan_; but it was said to be very rare, and I never was fortunate enough to meet with one.

Pl. 169

[Ill.u.s.tration]