These "horned toads" make a squeaking noise when teazed, not at all loud or strong in proportion to their size. Ill-tempered individuals jump at their aggressor and can inflict rather painful nips. They hibernate during the dry season in the ground.
Lepidobatrachus.–Large teeth in the upper jaw, and two large tooth-like projections in the lower jaw near the symphysis. Vomer toothless. Sacral diapophyses not dilated. Tongue round, and free behind. Tympanum distinct. Great development of the membrane-bones on the head, and a weaker ossification in the skin of the back, recalling that in Ceratophrys. The eyes are closely set together, and the nostrils take up the most elevated portion of the head. Pupil horizontal. The two species of this genus were discovered by Budgett[[93]] in the Paraguayan Chaco. L. asper lives continually in muddy pools, floating with just the eyes and nostrils above the surface. If disturbed it slowly sinks to the bottom, leaving no ripple. It feeds largely on Bufo granulosus. Total length from about 3 inches. The skin of the upper parts is tubercular, tough, and of a dull leaden colour; the tips of the toes are horny. L. laevis is smooth and slimy, "with the organs of the lateral line showing clearly upon it," a feature elsewhere known to exist in Xenopus and Leptobrachium only.
Leptodactylus = Cystignathus.–Some twenty species inhabit tropical America, from Central Mexico to Buenos Aires. The fingers and toes are not webbed and end mostly in points; only a few species, e.g. L. hylaeodactylus, having small adhesive discs. The legs are long and the general appearance is very much like that of an ordinary frog.
One of the commonest and prettiest Brazilian species is L. ocellatus, which is characterised by a number of longitudinal glandular folds on the back and flanks. The colour of the upper parts is olive-brown, that of the prominent folds is yellowish white, interspersed with black spots. The under parts are yellowish white, with blackish marblings on the throat. The males have a sharp black spur on the inner carpal edge and one on the rudiment of the thumb. Total length about 4 inches.
According to Hensel[[94]] the spawning takes place in Rio Grande do Sul after hibernation. The voice of the male is then very loud, resembling the sound made by a carpenter chopping a beam. They repair to ponds and produce a cup-shaped puddle, about 1 foot in width, by raising a wall of mud, which separates the inner water from that of the pond. The tadpoles remain in this nursery until the spring-rains demolish it and set the young ones free. Drought causes the drying up of these water-pans and subsequent destruction of the brood.
L. mystacinus is another Brazilian species, about 2 inches in length. Its specific name refers to the dark brown stripe which runs from the tip of the mouth through the eye to the tympanum. This species is thoroughly terrestrial, and never enters the water. It digs a cavity, the size of an ordinary tea-cup, under stones or rotten trunks, always in the neighbourhood of ponds and just so high above the water that the latter can rise up to the nest in the rainy reason. The straw-coloured eggs are laid in this cavity, and are enveloped in a foamy, sticky mass, like the well-beaten white of an egg. The young tadpoles seem to live on this froth until the rains set them free. When, however, the rains delay and a drought kills the broods of other less circumspect species, these tadpoles, still provided with gills and long tails, remain in their moist nest or withdraw further beneath the rotten stumps, huddled together in large numbers until the next rainy season.
Similar nursing habits have been recorded of L. albilabris, which inhabits Mexico, Cuba, and several other West Indian islands. The same applies to L. typhonius. Gundlach found eggs of this "Sapo" in Puerto Rico on the 4th of November; on the 25th the young showed the first signs of hind-limbs, on the 3rd of December of fore-limbs, and on the 7th of the same month they began to climb out of the water.
Paludicola is a semi-aquatic genus with some eighteen species, ranging from Mexico to Patagonia and across the Andes into Chili. Some of them have a peculiar gland on the lumbar region, or large, flat warts on the back, sometimes arranged in longitudinal folds. The toes are slightly webbed, or free, according to the more or less pronounced aquatic habits.
Fig. 45.–Paludicola fuscomaculata, × 1, with vocal sacs partly filled.