73 



Some species of Bufo are provided with bony ridges on the 

 upper surface of the head, viz: a can thai ridge along the 

 canthus rostralis; a supraorbital ridge along the inner 

 edge of the upper eyelid, which may be continued into a 

 praeorbital and a postorbital ridge and, backwards, 

 into a parietal ridge; and a supratympanic ridge 

 above the tympanum. 



Tadpoles. — Eyes superior. Spiraculum sinistral. Vent 

 median. Upper crest of tail not extending on to the body. 

 Mouth normal, sometimes much enlarged ; series of papillae 

 absent along upper border of upper lip; series of teeth 2/3. 



Distribution: cosmopolitan, except New Guinea, Poly- 

 nesia, Australia and Madagascar. In the Indo-Australian Ar- 

 chipelago occurring only in the western part, including Celebes. 



Synopsis of the Species. 



A, Head without bony ridges. 



1. Parotoids not distinct, rarely ') present, but than 

 very narrow. 



1. Tympanum not quite half the width of the 

 eye. Heel reaching the eye or between eye 



and tip of snout \. B. Icpioptis p. 75. 



2. Tympanum at least half the width of the eye. 

 a. Heel reaching the eye or between eye and 



tip of snout 2. B. penangensis p. 75. 



^. Heel reaching far beyond the tip of the snout. 3. B. jerboa p. 76. 



c. Heel reaching the tympanum ^. B. fuligi/ietis p. 77. 



II. Parotoids distinct. 



1. First finger shorter than second S- ^- criientatus p. 78. 



2. First finger at least as long as second. 



a. Tympanum '/^ the width of the eye. A 



tarsal fold 6. B. sumatranus p. 78. 



b. Tympanum 1/2 to ^/^ the width of the eye. 



No tarsal fold 7. j5. valhallac p. 79. 



B. Head with bony ridges. 

 I. No parietal ridge. 



1. No parotoids. Only a canthal ridge present . 8 B. spinulifcr p. 79. 



2. Parotoids and supratympanic ridges present. 

 a. Supratympanic ridge narrow. 



x. No tarsal fold (). B. melanostictus p. 80. 



l) See 3. B. jerboa. 



