158 VERTEBRATE ANIMALS OF THE UNITED STATES 



the main group several internal structures are important — the ribs, 

 vertebrae, sacrum and pectoral girdle. 



Key to the Families of the SaUentia 



ai Ribs present i . DiscoglossidcB. 



a2 Ribs absent; no anal processes. 



bi Pupil of eye vertical; parotoid glands present 2. Pelobatidce. 



hi Pupil of eye horizontal or round. 



Ci Parotoid glands present (Fig. 81) toads 3. Bufonidce. 



C2 Parotoid glands absent. 



di Expanded adhesive disks at ends of digits; tree toads 



(Figs. 88 and 89) 4. Hylidce. 



6.2 No such disks present. 



ei Upper jaw with teeth; frogs; waist narrow; legs long. 5. Ranidce. 



Co Upper jaw without teeth ; waist wide; legs short 6. Microhylidce. 



Family i . Discoglossidae. — Ribs present ; vertebrae opisthocoelous ; 

 male with tail-like process; female with short anal tube; tongue with 

 but little movement; pelvic girdle arciferous (coracoids and precora- 

 coids overlapping midventrally) ; larvae with a midventral spiracle : 

 5 genera, i in New Zealand, 3 in the Palearctic region and i in western 

 America. 



Ascaphus Stejneger, Tympanum and Eustachian tube wanting; 

 tongue free behind; sternum cartilaginous; maxillary and vomerine 

 teeth present; parotoid gland well developed: i species. 



A. truei Stej. Color reddish brown or slate gray above, with a few 

 blackish markings, and whitish beneath; a black streak from the nostril 

 through the eye and along the lower border of the parotoid gland; 

 length 40 mm.; length of hind leg 59 mm.: Washington, western 

 Montana Oregon and northern California. 



Family 2. Pelobatidae. — Spadefoot toads. Body of medium size; 

 head broad and short; eyes prominent; maxillary teeth present; pelvic 

 girdle arciferous (coracoids and precoracoids overlapping midventrally) ; 

 heel with a prominent spur which is used in digging: 5 genera and 70 

 species, in the Nearctic and Palearctic regions; i genus in the United 

 States. 



Scaphiopus Holbrook. Body toad-like; tympanum present; hind 

 feet partly webbed; vomerine teeth present: 3 species, in the United 

 States. 



Key to the Species of Scaphiopus 



ai In the eastern and Gulf States; parotoid glands and tympanum 



distinct 5. holbrookii. 



