Engystoma, with about five species in the Southern States, Central and South America, is the type-genus of the whole family, chiefly on account of priority of name. It is fairly characteristic in so far as the mouth forms a narrow, somewhat projecting snout; the precoracoids, the clavicles, and the omosternum are absent, the palate is devoid of teeth, the lining of the mouth forms a dermal ridge across the palate and another in front of the oesophagus, the tympanum is hidden, the sacral diapophyses are moderately dilated, and the tongue is elliptical and free behind. The pupil is vertical. The fingers and toes are free, ending in slightly dilated or blunt tips; the terminal phalanges are simple and the hind-limbs are short. The male has a subgular vocal sac.
The most northern species is E. carolinense, living in the Southern United States, concealed under the bark of fallen trees or in old fences. The skin is smooth, but forms a fold across the head, behind the eyes. The general colour is brown, with light, whitish dots on the under parts. Total length 1 inch.
Breviceps is a South African genus with three species. The coracoids are very strong and directed backwards, but so broadened that they form a long and strong symphysis, touching in front that of the precoracoids, which stand transversely and are well developed. The metasternum is cartilaginous and decidedly small. The sacral vertebra has much dilated diapophyses and is co-ossified with the coccyx. The general appearance is extremely stout and short, the head being almost drawn into the nearly globular body, and ending in a short snout with a small mouth-opening. The tongue is long and oval, not nicked, but slightly free behind. B. mossambicus is about 2 inches long, and looks like an overstuffed round bag, out of which the short arms and legs project from the elbows and knee-joints only. The tarsus is provided with a strong horny, spade-like tubercle, which enables the creature to dig into the ground, and into the nests of termites, which seem to be its chief food. Peters found this species in enormous numbers, during the tropical rains, coming out of the ground, whither they withdraw again completely for the dry season. The skin is smooth, reddish brown above, with darker patches; the under parts are dull white, with a large black patch on the throat.
Hemisus is another African genus, with two species, H. guttatum in Natal, and H. sudanense in East and West Africa. This genus is so exceptional in its shoulder-girdle, that Cope separated it from all the other Anura as a special sub-order Gastrechmia. The precoracoids are extremely strong, and form a broad symphysis from which springs the long cartilaginous omosternum; the coracoids are slender, very long, and converge backwards to a narrow symphysis, and there is no metasternum. The two symphyses are connected by a narrow cartilaginous median bar, probably produced by the much modified epicoracoid cartilages. However, except for the reverse development shown by the omo- and meta-sternum, it is easy to connect this apparently quite anomalous shoulder-girdle of Hemisus with that of Breviceps. (cf. Fig. 5, 5 and 6, p. [25]). The sacral diapophyses are slightly dilated; the fingers and toes are free and end in points. The tongue is triangular, broader in front. The lining of the mouth forms a transverse ridge across the palate, and another in front of the oesophagus. The male has a subgular sac. The general shape is stout, the head small and ending in a pointed snout. Colour brown above, with whitish spots. Total length about 2 inches.
Glyphoglossus has a peculiar tongue. It is elongated, notched behind and in front, divided into two lateral halves by a deep groove; moreover, the tongue is not only extensively free behind, but also slightly so in front. The skin of the palate forms a transverse serrated ridge. The precoracoids and the omosternum are absent; the metasternum is a well-developed cartilaginous plate. The sacral diapophyses are moderately dilated; the terminal phalanges are simple. G. molossus, the only species, is olive-brown above, marbled on the sides; the under parts are uniformly whitish. This creature, about 2 inches in length, looks like a roundish bag, with a ridiculous, short face. The type-specimen, still the only one known, was taken by Dr Theobald under the following circumstances:–"I had halted one day within the tidal portion of the Irawaddy delta, to enable my boatmen to prepare their dinner. One of my servants, having cooked his rice, poured out the hot water as usual on the ground, and some of it went down a hole that happened to be near the spot. No sooner, however, had the hot water disappeared than out scrambled in great haste a fine Glyphoglossus, only, alas! to be transferred to a collecting jar."
Phrynella.–The tongue is heart-shaped, free behind. The palate is smooth and toothless. The fingers and toes end in small discs, supported by T-shaped phalanges; the fingers are free, the toes extensively webbed. Precoracoids absent; metasternum cartilaginous. Pupil horizontal. Malay Peninsula.
Ph. pollicaris is dark olive brown above; an oblique yellow line runs from the eye to the angle of the mouth; a pale yellow mark, across the forehead, through the eyes, and down the sides of the body. A dark-centred yellow patch on the anal region. The limbs are banded yellow and brown. The under parts are brown, with paler specks, dark on the throat. Iris red brown. The whole coloration changes considerably.
"They inhabit the hills of Perak from 3000 feet upwards, and live in holes in trees, which are so situated as to contain more or less rain-water. They have a loud flute-like, musical note, which they utter at irregular intervals, principally during the night. The form and size of the hole in which they are seem to have a great deal to do with the loudness of the note, as specimens when extracted from their holes have far more feeble vocal powers than they had when in them. These frogs blow themselves out with air, and look more like bladders than anything else. When inflated they float on the surface of the water, and will remain motionless for a long time, with legs and arms stretched out."[[101]]
Callula.–The tongue is round, entire, and free behind. The palatine bones form an acute, sometimes toothed ridge across the palate; two dermal serrated ridges in front of the oesophagus. Fingers free, sometimes with dilated tips, supported by T-shaped phalanges. Precoracoids and omosternum absent; metasternum cartilaginous. Pupil round. About seven species in the Indian region.
C. pulchra.–The following account has been extracted from Mr. S. S. Flower's observations:[[102]]–