vi ENGYSTOMATIDAE ENGYSTOMATINAE 225 



smooth skin, olive-brown above with darker spots. B. macro- 

 stomus, 2 inches in length, is distinguished by its larger size, and 

 by its completely webbed toes. 



Fam. 6. Engystomatidae (Narrow-mouthed Toads). Firmi- 

 sternia with dilated sacral diapophyses. 



Sub-Fam. 1. Engystomatinae. Without teeth in the upper 

 jaw. Although there are only about 6 species known, these have 

 been grouped into more than two dozen genera, many of which 

 are represented by one or two species only. The range of this 

 sub-family is peculiar, namely, Neotropical and Palaeotropical. 

 Scaphiophryne and Ehombophryne are peculiar to Madagascar; 

 Calophrynus occurs in the same island and in the Indian region ; 

 Xenobatrachus, Sphenophryne, Liophryne, Mantophryne, Callulops 

 and Xenorhina live in New Guinea. Breviceps, Cacosternum and 

 Hemisus are confined to Africa, while of Phrynomantis two species 

 live in Africa, and the third in the Malay island of Amboina. 

 Such freaks of distribution indicate either that many of these 

 genera are not established upon very valid characters, or that 

 their respective species are instances of convergent evolution, and 

 do not form natural genetic groups. 



Many of the members of this sub-family live upon ants and 

 termites, and it is a well-known fact, not restricted to the Anura, 

 that this kind of fare has a peculiar, modifying influence upon 

 the structure of the mouth, teeth, tongue, limbs, and various 

 other organs. In the present case the tongue is not much 

 affected ; it is, with few exceptions, more or less oval, not nicked, 

 but free behind ; in the Indian Glyphoglossus and in Rhombophryne 

 of Madagascar only is it modified into a rather long and grooved, 

 almost double, apparatus. 



A very common feature is the small size of the mouth and 

 the formation of a snout, which projects beyond the upper rim of 

 the mouth and beyond the nostrils. Such a prominent and 

 pointed snout is well developed in Rhinoderma, Phryniscus, Calo- 

 phrynus, Stereocyclops, Hypopachus and Engystoma. The mouth 

 is very narrow in Cacopus, Glyphoglossus, Breviceps, Ehombo- 

 phryne, and Hemisus, all creatures which seem to be confirmed 

 eaters of ants and termites. However, it must not be supposed 

 that the mouth of all the genera is narrow, although this 

 character, rather marked in Engystoma, is now embodied in the 

 name of the family. A peculiar development of the palatal region 



VOL. VIII Q 



