96 ON THE STRUCTURES AND DISTRIBUTION OF THE 



a. Prefrontals well separated, rarely the convexities of the inner 

 borders in contact. 

 b. Manubrium cartilaginous. 

 Muzzle and canthus rostralis angulated, projecting ; vomerine teeth ; 



digital dilatations small, Enhtdrobius.* 



Muzzle and canthus rostralis contracted, little marked; vomerine 



teeth ; digital dilatations large, EpiRHEXis.t 



Muzzle and canthus rostralis prominent, angulated ; no vomerine teeth, Phtllobates. J 



bb. Manubrium osseous, styloid. 

 Muzzle and canthus rostralis angulated ; no vomerine teeth, . . Limnocharis. 

 CM. Prefrontals united throughout by close suture, and usually 

 in contact with frontoparietals. 

 Abdomen smooth ; xiphisternum broad, ..... Lithodttes. 



Abdomen areolate ; xiphisternum slender, entirely cartilaginous, . Hylobes. 



Group VI. Cystignathi. — Frontoparietals and auditory apparatus fully developed. 

 Cephalic derm free. External metatarsi bound, digits free, terminal phalanges 

 simple. Xiphisternum a distinctly defined slender osseous style, with distal 

 undivided cartilaginous disc. 



a. Xiphisternal style emarginate, and with two distal cartilagi- 

 nous discs. 

 Form toad-like ; no parotoids or vomerine teeth ; isolated inguinal 



glands ; two acute metatarsal spurs ; pupil horizontal, . . Gomphobates. 

 ( Form more elongate ; no parotoids or vomerine teeth ; no inguinal 



' I glands ; metatarsal tubercles small, Tarsopterus. 



aa. Xiphisternal style and distal disc undivided. 



No inguinal glands, Cystignathus. 



Glandular aggregations on the loins, ...... Gnathophysa. 



Genera incertge sedis. 



1. Probably in Group Ceratophrydes. 



Superior cranial plane much contracted, with elevated ridges behind. 

 Eyelids not prolonged ; no cuneiform shovel or parotoid glands ; 

 small dilatations on toes of posterior extremity ; no palmations ; 

 belly areolate, Strabomantis. 



2. Among Cystignathi, or a new group. 



Superior cranial plane contracted, probably no fontanelle ; auditory 

 apparatus undeveloped; digits webbed, outer metatarsi bound, no 

 dilatations ; no vomerine teeth ; pupil round, .... Telmatobius. 



* Includes Elosia Tschudi. 



t Type Batrachyla longipes Baird. 



J Includes Crossodactylus Dum., Bibr. ' 



