Drawn from Nature on stone by B. Waterhouse Hawkins.
Printed by C. Hullmandel.
| 1. 2. | Rhinoderma Darwinii. | Nat. Size. |
| 3. 4. 5. | Phryniscus nigricans. | |
| 6. | Uperodon. ornatum. |
Of this species, which has been described under different names by many naturalists, and the synonymy of which has only lately been cleared up by Mons. Bibron, there exist numerous specimens in the collection of Mr. Darwin, who found it at Buenos Ayres, and also in the Archipelago of Chonos, on the west coast of South America. It is certainly remarkable that the same species should be found on the opposite sides of the Continent; but on a careful examination I do not find any specific distinctions between the specimens from the different localities. The Prince de Wied has described it as found at Brazil, under the name of Bufo cinctus, and it is also well known as having been repeatedly procured in Peru and in Chile; but Mons. Bibron has in his work considered them all as belonging to but one species. The following account of its habits as given by Mr. Darwin is very curious and interesting:—“These Toads are exceedingly abundant all over the treeless damp mountains of granite, crawling about, and eating during the daytime, and making a noise similar to that which is commonly used in England to quicken horses. Many of them on being touched close their eyes, arch their back, and draw up their legs (as if the spinal marrow was divided), probably as an artifice. They are remarkable from their curious manner of running like the Natter Jack of England; they scarcely ever jump, neither do they crawl like a toad, but run very quickly. Their bright colours give them a very strange appearance. They abound at an elevation of 500 to 2500 feet.”
Dorso granuloso, scabriusculo. Pedibus posticis subpalmatis. Corpore membrisque nigris, abdomine maculâ magnâ transversâ ad partem posteriorem et maculâ rotunda utrinque medium versus, palmis atque plantis, omnibus coccineis.
Habitat, Maldonado and Bahia Blanca.
This curious little species has been described by Weigman under the present name,—by Tschudi under the generic name of Chaunus, and fully by Bibron, who retained the name originally given to it by Weigman. It now remains only to correct, from Mr. Darwin’s notes, some points respecting the colours, which had been mis-stated in consequence of the action of the spirit in which the specimen had been preserved. The colour of this curious miniature representation of a Toad, is “ink black,” excepting the palms and soles of the feet, a large transverse spot across the posterior part of the abdomen, two smaller ones near the middle, and in some specimens a few scattered little spots, all of the most intense vermilion red. There is one specimen from Bahia Blanca which has also some small “buff-orange” spots on the upper part.[4] Mr. Darwin observes that “the appearance of the vermilion colour is as if the animal had crawled over a newly painted board;” and he adds—“This Toad inhabits the most dry and sandy plains of Bahia Blanca, where there is no appearance of water ever lodging.” The other specimens were taken at Maldonado, where it inhabits the sand-dunes near the coast. Mr. Darwin threw one into a pool of fresh-water, but he found it could hardly swim, and he thinks, if unassisted, it would have been soon drowned.
4. This specimen from Bahia Blanca has a much smoother skin than the others; but from its similarity in all other characters there can be no doubt of its specific identity with them.
This species is diurnal in its habits, and may be daily seen under a scorching sun, crawling over the parched and loose sand. M. D’Orbigny brought specimens from Monte Video.
| DIMENSIONS. | |||
|---|---|---|---|
| Inches. | Lines. | ||
| Length | of the head and body | 1 | 0 |
| of the anterior extremities | 0 | 5 | |
| of the posterior extremities | 0 | 8 | |
Capite multò latiore quam longiore. Dorso olivaceo, maculis fuscis, albo marginatis.
Habitat Buenos Ayres.
Description.—Head more than half as broad again as it is long, and equal in breadth to half the entire length of the head and body. Muzzle rounded. Nostrils oval, opening upwards and a little outwards. Eyes rather large, the upper eyelids forming perfect flaps, which entirely cover the eyes. Body rounded, very broad. The shoulders and thighs wholly concealed by the skin of the body. Limbs very short. The anterior feet very broad. The toes somewhat depressed, very short, bordered with a fold of skin. Hinder feet with the toes more depressed and more distinctly bordered. Back covered with small glands.
Colour.—The colour of the upper surface is dark olive, becoming lighter at the sides, and having numerous dark brown spots, which are round, oval, elliptical, or irregular, of very various sizes, placed somewhat symmetrically, and each bordered with a whitish or yellow line. Beneath pale, excepting the throat, which is black.
I have ventured to consider this remarkable amphibian as specifically distinct from U. marmoratum of Bibron; a conclusion to which I have been almost imperatively led, by the fact of its inhabiting a different hemisphere from all known specimens of that species. The other was found by M. Leschenault in the interior of the peninsula of India: the specimen from which the present description is taken was obtained by Mr. Darwin at Buenos Ayres. Notwithstanding the similarity of the two species, which is so great as to have led Mons. Bibron to consider them as identical, I could not assent to such an anomaly as the existence of an animal, at once so rare and possessed of such limited powers of locomotion, in two regions so widely remote. I have not the opportunity of comparing the specimens of the former species with the present, but, even from Mons. Bibron’s description, I believe that I can discover sufficient discrepancies between the animals, to bear me out in the view I have taken. These discrepancies I venture to place in the following tabular view, and leave zoologists to form their own conclusions.
| UPERODON MARMORATUM. | UPERODON ORNATUM. |
|---|---|
| “La tête offre en arrière une largeur à peu près égale à son longueur totale, laquelle entre pour le quart environ dans l’étendue de l’animal.” | Head fully half as broad again as it is long, and equal in breadth to half the total length of the animal. |
| “On pourrait considérer la peau comme étant parfaitement lisse, si l’on ne voyait éparses sur le dessus du tronc un certain nombre de verrues glanduleuses d’un assez grand diamètre relativement à la grosseur de l’animal, mais fort peu saillantes ou à peine convexes.” | Back covered with numerous small glandular tubercles, notably elevated. |
| “Les parties supérieures de ce Batracien présentent sur un fond olivâtre, d’énormes taches brunes, toutes confluentes, ou s’anastomosant diversement.”[5] | All the spots on the back are quite distinct, not in any way passing into each other or connected, and each encircled by a white line. |
5. Bibr. Rept. VIII. p. 749.
| Page | Changed from | Changed to |
|---|---|---|
| 16 | minutè granulato. Seriebus duabas squamarum supralabialium. Femorum facie | minutè granulato. Seriebus duabus squamarum supralabialium. Femorum facie |