4i
ZOOLOGICAL
HYLIDA! (Typical Tree Frogs; 291 Species). Plate 21, Map iii.
The distribution of this large and important family is remarkable, and the mere colouring of a map might be very misleading. Although found in all the zoogeographical regions except the Ethiopian, the great majority of the species are Neotropical. Only two occur in the Palsearctic region, one of which is confined to Corea while the other is found throughout the warmer parts of the region, and has a wider range than any other species. One species occurs in the extreme north-east of India, and one in Southern China and Formosa. About 60 are found in the Australian region and about 25 in North America. This leaves a balance of about 100 species for Central and South America (including half a dozen in the West Indies), where it is evident that the metropolis of the family lies. The Tree-Frogs, with their peculiar finger-discs, vivid and often protective coloration, and remarkabie nursing habits, form altogether an unusually interesting family of Tailless Amphibians. Fourteen genera are recognised, but 221 species fall into the typical one, Hyla.
AMPHIGNATHODONTIDA¡ (Amphignathodon and Grypiscus;
2 Species). Plate 21, Map iii.
The two species, one of each genus, which together constitute this family, are found in Ecuador and near Rio de Janeiro respectively. Both upper and lower jaws are toothed.
BUFONIDA¡ (Toads; 174 Species). Plate 21, Map iii.
This, though not the most numerous in species, is by far the most widely distributed family among the Amphibians, having representatives in all parts of the world save Madagascar, New Zealand, New Guinea, and the greater part of Polynesia. Thirteen genera have been described, but 140 species belong to the typical one, Bufo. This genus is cosmopolitan, except that it is not represented in Australia, its place being apparently taken by Pseudophryne, with seven species, and two other peculiar genera. Three species of Bufo are found in Europe, namely B. vulgaris (the Common Toad), B. viridis and B. calamita (the Natterjack Toad). The first and last are found in Britain, the Common Toad throughout England and Scotland (but not in Ireland), and the Natterjack in many English counties, on the Moray Firth in Scotland, and in Ireland.
PELOBATIDA¡ (Spade-footed Toad and Allies; 33 Species).
Plate 21, Map iv.
The Pelobatidse have an interesting distribution, occurring in three detached areas, viz., North America and Mexico; Europe, Asia Minor and Palestine; and the East Indies from Ceylon and the Eastern Himalayas to New Guinea. Nine genera have been described, the largest being Lepto-brachium, with nine species occurring in the East Indies, the next Scaphiopus containing all the New World species, 10 in number. Three genera, each with a single species, are confined to New Guinea, while four species (two Pelobates and two Pelodytes) occur in Europe. The best-known species is the “ Spade-footed Toad ” (Pelobates fuscus) which occurs throughout the whole of Central Europe.
DISCOGLOSSIDA; (Disc-tongued Frogs; 10 Species).
Plate 21, Map iv.
This again is a family with a curious distribution. Five genera are described, three of which are Palsearctic, while the other two contain a single species each, confined to New Zealand (Liopelma hochstetteri) and Washington Territory, North America (Ascaphus truei) respectively. Five species occur in Europe. These are (1) Discoglossus pictus, found only in the South; (2) the Fire-bellied Toad (Bombinator igneus) occurring in Eastern Europe; (3) the Yellow-bellied Toad (Bombinator pachypus) of Southern and Western Europe, and (4 and 5) two species of “Midwife ” Toad (Alytes obstetricans and A. cisternasii) found in the west.
PIPIDA: (Surinam Toad, &c.; 2 Species). Plate 21, Map iv.
This family includes only two genera, each with a single species. The better known of these is the famous Surinam Toad (Pipa americana), which is a native of Northern Brazil and the Guianas. The chief peculiarities in structure, both in this and the second genus, are the total absence of both tongue and teeth. The Surinam Toad is a large and clumsy creature, chiefly remarkable for the singular way in which the eggs are taken care of during development. These are laid in the usual manner in the water and afterwards transferred by the male to the back of the female. Each egg then sinks into the skin and becomes afterwards covered by a flap or lid. Thus the mother toad carries her whole progeny on her back, each in a separate little compartment, until the time of hatching.
Hymenochirus, the other genus, contains a single species (H. bcettgeri) which has hitherto only been found in German East Africa and the French Congo.
DACTYLETHRIDA! (Clawed Toads; 6 Species).
Plate 21, Map iv.
The Clawed Toads, all belonging to a single genus (Xenopus or Dacty-lethra), are confined to tropical and South Africa. They are distinguished from their allies, the Pipidse, by the possession of teeth in the upper jaw. Xenopus leevis is the best-known species, and ranges from the Cape to Abyssinia. All these Toads are entirely aquatic in habit, even feeding beneath the surface of the water.
CLASS AMPHIBIA (Amphibians).
ORDER ANURA (Frogs and Toads;
1503 Species).
DENDROBATIDA¡ (Solid-chested Tree-Frogs; 26 Species).
Plate 21, Map i.
Were it not for important differences in their internal structure, these little arboreal frogs might very well be taken as Tree-Frogs of the family Hylidce, which they much resemble in external appearance as well as in habits. Some four genera have been described, whose distribution is somewhat remarkable. The typical genus Dendrobates contains 14 species confined to tropical America, one occurring in the island of San Domingo. Mantella, with eight species, and Stumpffia with two, are confined to Madagascar ; while Cardioglossa, recently described, has two species found in the Cameroons and the Gaboon.
RANIDA1 (Typical Frogs; 440 Species). Plate 21, Map i.
This vast assemblage of Frogs has a world-wide distribution, being absent only from Australia, New Zealand, and the greater part of South America. Over 40 genera have been differentiated, while the species are most numerous in the Oriental and Ethiopian regions. The typical genus Rana contains no fewer than 131 species, and eight of these occur in Europe. The Common Frog (Rana temporaria) is a familiar and abundant member of the British fauna, while the Edible Frog (R. esculenta) is still found in a few places in the eastern counties of England, where it was evidently introduced many years ago. The genus Rhacophorus, containing about 50 species, is interesting, containing as it does the so-called “ Flying Frogs ” of the Malay Archipelago. The feats performed by these frogs as they leap from the trees into the water have been much exaggerated; nevertheless the large webbed feet are undoubtedly used as parachutes, and are remarkable enough on this account alone.
CERATOBATRACHIDA1 (Ceratobatrachus; 1 Species). Plate 21,
Map i.
This family has been formed for the reception of a single species (Ceratobatrachus guentheri) recently described from the Solomon Islands. It differs from typical Ranidse in having teeth in the lower jaws.
GENYOPHRYNIDAl (Genyophryne; 1 Species). Plate 21, Map i.
The only member of this family is a frog known as Genyophryne thomsoni, recently found in Sudest Island, between New Guinea and the Louisiade Archipelago. It is distinguished from its closest allies, the Dyscophidse and Engystomatidse by having very small teeth on the front portion of the lower jaw.
DYSCOPHIDA: (Dyscophus, &c.; 22 Species). Plate 21, Map ii.
This small family, whose members are distinguished from the Engystomatidse by the presence of teeth in the upper jaw, has a curious distribution. About a dozen genera have been differentiated, eight of which are confined to the island of Madagascar, onedo Pegu and Burma, and one to Sarawak in Borneo. Red or pink is characteristic in the coloration of these frogs.
ENGYSTOMATIDA¡ (Narrow-mouthed Toads; 141 Species).
Plate 21, Map ii.
This is a large group of Frogs or Toads, containing no fewer than 43 genera, and distributed over the tropical regions of both Old and New Worlds. They are usually stout-bodied, those of the genus Breviceps (confined to Africa) excelling in this respect and assuming an almost globular shape.
DENDROPHRYNISCIDA: (Dendrophryniscus and Batrachophrynus;
4 Species). Plate 21, Map ii.
This small group is entirely Neotropical. Dendrophryniscus contains a single species found in the neighbourhood of Rio de Janeiro, while the other genus, Batrachophrynus, has three species confined to the Andes of Peru. These frogs are entirely without teeth.
CYSTIGNATHIDA! (Leptodactylus and Allies; 342 Species).
Plate 21, Map ii.
Next to the Ranidse. this is the largest family of Frogs, although its distribution is somewhat restricted. It is practically confined to the°Neo-tropical region and to Australia and Tasmania. Some 36 genera have been differentiated, 10 of which are Australian with about 30 species. Ceratophrys is probably the best-known genus, containing 16 species known as Horned Frogs or Toads. They have enormous mouths, and their habits are somewhat fierce. Important genera also are Leptodactylus, with 36 species called Piping Frogs, and Hylodes, with 107 species.
HEMIPHRACTIDA: (Hemiphractus, &c.; 8 Species).
Plate 21, Map iii.
This is a purely Neotropical family, with three genera. Hemiphractus contains two species which range from Colombia to Para; Ceratohyla has five, which live only in Ecuador; while Amphodus is represented by a single species which is found in the neighbourhood of Bahia. In these creatures both jaws are toothed.
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