226 ANURA 



CHAP- 



is possibly correlated with this food. The palate is mostly 

 toothless, but its skin is frequently raised into a transverse fold, 

 between or behind the vomers, and into a second fold in front 

 of the oesophagus ; these folds are sometimes rather hard and 

 serrated or denticulated. The palatine bones carry true teeth 

 in Rhombophryne, and sometimes in Callula ; in Xenobatraclms 

 the teeth are reduced to two large pairs. The tympanum is 

 usually hidden. 



The shape of the body is generally very stout. The limbs are 

 short, notably so in Glyphoglossus, Breviceps, Rhombophryne, 

 Hemisns, Stereocy clops and Cacopus. Others, for instance most 

 species of Microhyla, Phryniscus, Callula, and Sphenophryne, are 

 of a very slender build ; and their limbs, instead of being short 

 and well adapted to digging, are long and may even be provided 

 with typical adhesive discs, supported by T-shaped phalanges, 

 especially in the two genera last named, and in Scaphiophryne and 

 Phrynomantis. However, none of the forms provided with discs 

 are known to be arboreal. 



Exceptional diversity is shown in the shoulder -girdle and 

 sternum. The omosternum occurs only in Rhinoderma and 

 Hemisus. The metasternum is a cartilaginous plate, very large 

 in Cacopus, distinctly small in Breviceps, and almost absent in 

 Hemisus. The precoracoids and clavicles show all stages from 

 a well -developed condition (Breviceps, Rhombophryne, Hemisus, 

 Rhinoderma, Phryniscus and Brachycephalus) to complete absence. 

 The circumstance that these bars are very weak in Melano- 

 batrachus, Calophrynus, Scaphiophryne and Hypopachus, i.e. 

 in Palaso- and Neo-tropical genera, indicates a widespread 

 tendency towards complete suppression, a feature independently 

 aimed at both in America (Engystoma) and in the Old 

 World. 



Until we know something about the habits of the members of 

 this much diversified sub-family, it is idle to connect the various 

 modifications with each other, and thus, by correlation, to find out 

 their meaning. Those forms which possess well-developed discs 

 on their fingers and toes are said not to be arboreal. What is the 

 true meaning of the prominent snout which is not restricted to the 

 digging forms ? Most of the good diggers have well-developed 

 precoracoid bars, and the coracoids are distinctly strengthened, 

 but in Glyphoglossus and in Cacopus the precoracoids are entirely 



