417 



meeting immovably; digits without intercalary cartilage; the com- 

 bination of disks and webs does not occur in the region. 



Atelopus. No disks; toes mostly enveloped in web; no vomerine or 

 maxillary teeth. 



Phyllobates. Digital disks well developed, with two scales above; 

 toes free; no vomerine teeth; maxillary teeth present; eggs laid on 

 land; tadpoles transported to water on back of male. 



Dendrobates. Like Phyllobates but no maxillary teeth; eggs laid on land; 

 tadpoles transported to water on back of male. 

 Family Hylidae. Shoulder girdle arciferous; digits with an intercalary 

 cartilage; disks well developed and toes webbed in region. 



Hemiphr actus. A well-developed bony casque on head; eggs carried 

 on back; no tadpole stage. 



Hyla. Eyes lateral; pupil horizontal, terminal phalanges claw-shaped; 

 eggs laid in water. 



Agalychnis. Eyes lateral; pupil vertical; terminal phalanges claw- 

 shaped; eggs laid above water; a tadpole stage. 



Centrolene. Eyes directed forward; pupil horizontal; terminal pha- 

 langes T-shaped; eggs laid above water; a tadpole stage. 

 Suborder Diplasiocoela. Vertebra 8 biconcave; first seven procoelous. 

 Family Brevicipitidae. Sacral diapophyses dilated; head extraordina- 

 rily minute and pointed in region. 



Elechostocleis. Toes with neither disk nor web. 

 Family Ranidae. Sacral diapophyses cylindrical; head normal. 



Rana. Toes webbed; digital disks not well developed; eggs laid in 

 water. 



The superficial resemblance between Bufo and Engystomops 

 is very close. Lithodytes is superficially like Phyllobates. Lepto- 

 dactylus resembles Rana. ManyEleutherodactyli are superficially 

 like species of Hyla. The resemblance between Hyla', Agalychnis, 

 and Centrolene is close and they are related. 



Keys to genera containing more than one species in the region 

 follow. 



Key to Canal Zone Oedipus. 



A. Legs well developed; not wormlike; 14 costal grooves .. lignicolor. 

 AA, Legs minute; wormlike; 17 costal grooves. 



B. Snout rounded; eyes well developed; usually a light dorsal 



band complex. 



BB. Snout pointed; eyes minute; uniform », parvipes. 



Key to Canal Zone Bufo. 



A. No head ridges haematiticus. 



AA. Head ridges present. 



B. Ridges present only around eye granulosus. 



