vi ENGYSTO-MAirNAE DYSCOPHINAE 235 



a deep guttuial croak, ' wau-auhhhli," very stridfiit and prolonged. 

 The males croak while tioating on the surface of the water, the 

 sintde vocal sac under the mouth inflated like a yiobe, and the 

 arms and legs extended. They can hoj) well on land and are good 

 swinnners. The skin is excessively slimy : tlie secretion comes off 

 profusely, and dries on the hand into a sort of wliite gum, witli 

 a ftiint aromatic smell. This gum dissolves in liot water and 

 coagulates in cold. The general appearance of these frogs is very 

 stout, their girth being about twice the length from snout to 

 vent. 1'lie tongue, which is oblong in s])irit specimens, in life is 

 very elastic, assuming, when extended, a vermiform shape and 

 reaching about 4 cm. in length. They appear after sunset, 

 crawling- on old wood and feeding,- on white ants." 



Sub-Fam. 2. Dyscophinae. — IFith teeth in the uj^jjer jmv. 



Tliis small group of nine genera, with scarcely more than one 

 doi:en species, all with one exception living in Madagascar, has 

 been separated by Boulenger from the Engystomatinae merely on 

 account of the presence of teeth on the upper jaw and on the 

 vomerine margin of the palatine bones. He himself remarks that 

 CallueUa may be considered a toothed Hypo2^achus, and Pletlio- 

 (toiitoliyla a toothed CaUuhi. These are obvious cases of con- 

 vergent analogy. Except for the teeth, the Indian CallueUa 

 would be merged into the American Hyixypachus, and this would 

 present an instance of the most puzzling geographical distribution. 

 In the case of the other two genera, one Indian and Malayan, the 

 other Malagasy, no such suspicion would arise, since there are 

 many other instances of such a coincidence of distribution. There 

 is the same divergence or unsettled condition in the modification 

 of various parts in the Dyscophinae as in the Engystomatinae. 

 Tlie precoracoid bars are weak and curved backwards, and closely 

 ])ressed against the strong coracoids, in Dyscophtcs, CallueUa and 

 Flatypelis, while these elements are reduced to imossified bars, 

 and the clavicular ])ortions completely lost, in Plethodontohyla 

 and in Phryiiorarc 'I'he omosternum is absent and the meta- 

 sternum is small in all except Dys'-oj^hua, in which lioth these 

 parts are exceptionally well developed and large, although re- 

 maining unossified. The palate of J)ysco2)]ius and CallueUa i^ 

 provided with curious, serrated dermal folds like those which are 

 so common in the Engystomatinae: and well-developed discs on 

 the tingers and toes, supported by T-shaped yihalanges, are 



