4. bufo. 285 



Tympanum absent ; no tarsal fold ; first 



finger not longer than second 18. variegatus, p. 293. 



Tympanum distinct, half the width of 



the eve 23. hcdophilus, p. 295. 



Inner metatarsal tubercle very large, 



shovel-shaped 33. compactilis, p. 302. 



Tympanum hidden : no tarsal fold ; first 



finger longer than second 34. simus, p. 302. 



Tympanum distinct, very small; paro- 



toids short 35. spimdosus, p. 302. 



3. Toes entirely webbed, or nearly so. 



Skin perfectly smooth 15. politus, p. 292. 



Skin warty 24. boreas, p. 296. 



P>. Head with bony ridges. 



1. A tympanum. 



a. Upper eyelid normal. 



a. Supraorbital and postorbital ridges straight, forming 

 together a right angle. 



* Derm of head free from cranial ossification. 

 Tarotoids close to the eye ; metatarsal 



tubercles blunt 43. intermedins, p. 307. 



Parotoids close to the eye ; metatarsal 



tubercles shovel-shaped 44. dipternus, p. 308. 



Tympanum large, very distinct 45. lenfriginosus, p. 308. 



Tympanum small ; toes nearly entirely 



webbed 46. occipitalis, p. 310. 



Tympanum hidden 54. bocourtii, p. 314. 



Tympanum distinct, half the size of the 



eye ; toes extensively webbed 04. coniferus, p. 321. 



** Derm of head involved in crauial ossification. 



Tympanum at least half the width of the 



eye 74. peltocephalus, p. 325. 



Temporal region entirely bouy, the tym- 

 panum being a mere foramen perfora- 

 ting a shield of bone 75. empusus, p. 32'!. 



(i. Supraorbital and postorbital ridges forming together 

 ;i more or less regular curve, with the parietal 

 ridges (if present) a ^-shaped figure. 



* Edge of the upper jaw 



strongly dilated hori- 

 zontally (!8. cForbignyi, p. 322. 



** Angles of jaws projecting. 59. typhonius, p. 317. 



