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Show 50 ZOOLOGY OF TilE VOYAGE OF THE BEAGLE. This curious little species has been described by W eigman under the b T chudi under the generic name of C!taunus, and fully by present name,- Y s . 't b w igman It now Bibron who retained the name originally gtven to 1 y . e . . remam. s' only to correct, fr· om M r. Darwin's notes, some po.m ts rfe shp ectm·g · th· e 1 hich had been mis-stated in consequence of the actwn o. t e s.pt.nt m co ours, w . d b d The colour of this cunous mmmture which the specimen ha een preserve . l f h representati·o n of a T oa d ' 1· 8 "·m k black' " excepting the palbmds and sto es o ltl e feet, a large transverse spot across tht.. posterior part of the a o~en, wo sma er. th 'ddle and in some specimens a few scattered httle spots, all of ones near e m1 , · Bl h' h the most m· tense verm1·1 ·t on re d . There is one specimen from Bahta anca .w tc has also some small "buff-orange" spots on the upper .part.* . Mr. D~rwm ob-serves that " the appearance of the vermilion colour IS ~s If the . amm~l had crawled over a newly painted board;" and he adds-" Tht~ Toad mhabtts 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 on~ into a .pool ~f fresh-water, but he found it could hardly swim, and he thinks, If unassisted, It would have been soon drowned. . This species is diurnal in its habits, and may be daily. seen under a scor~hm g sun, crawling over the parched and lo?se sand. M. D'Orbtgny bmught speCimens from Monte Video. DIMENSIONS. In. Lin. Length of the head and body .. .. .. .. .. .. . ... .. . . . 1 0 of the anterior extremities . . . . . . . . . . . . . . . 0 5 of the posterior extremities..... . ... .. ... . 0 8 GENus-UPERODON. Bibr. UPERODON ORNATUM. Milti. PLATE XX.-Fig. 6. Capite multo latiore quam longiore. Dorso olivaceo, maculisfuscis, albo mm·ginatis. Habitat Buenos Ayres. DEsCRIPTION.-IIead 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 * 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. REPTILES. 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 bE'tween 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. " La tete offre en arriere une largeur a peu pres egale a son longueur totale, laquelle entre pour le quart environ dans l'etendue de l'animal." " On pourrait considerer la pcau comme etant parfaiternent lisse, si l'on ne voyait eparses sur le dessus du tronc un certain nombrc de verrucs glandulcuscs d'un assez grand diametre relativement a la grosseur de !'animal, mais fort peu saillantes ou a peine convexes." " Les parties superieures de ce Batracien presentent sur un fond olivatre, d'enormcs taches brunes, toutes conjluentes, ou s'anastomosant UU diversemcnt." • UPERODON ORNATUM. Head fully half as broad again as it is long, and equal in breadth to half the total length of the animal. Back covered with numerous small glandular tubercles, notably elevated. 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. • Bibr. Rcpt. VIII. P· ':'49. |