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University of California Publications in Zoology [Vol. 27 
15'. Tail rounded or oval throughout. 
16. Thumb indistinct; fingers slender; coloration blackish above 
with numerous irregular light colored markings 
Aneides ferreus 117 
16'. Thumb distinct; fingers short; coloration brown above, with 
small rounded yellow spots. 
17. Spots fewer; mainland form Aneides lugubris lugubris 124 
17'. Spots more numerous; habitat South Farallon Island 
Aneides lugubris farallonensis 140 
1'. Tail absent in adults (a tail-like structure, traversed by cloaca, present in 
Ascaphus ); hind legs developed for leaping, much longer and stronger 
than forelegs Order Salientia 
18. A short tail-like process, not more than 34 length of body; no tympanic 
membrane Family Discoglossidae Ascaphus truei 143 
18'. No tail or tail-like process in adults; tympanic membrane present. 
19. Pupil of eye vertically elliptical; sole of hind foot smooth, without 
tubercles but with a single black cutting ‘spade’ on inner margin 
(pi. 10) Family Scaphiopodidae Scaphiopus hammondii 148 
19'. Pupil of eye rounded or horizontally elliptical; sole of hind foot never 
entirely without low rounded tubercles. 
20. An enlarged parotoid gland over shoulder region on each side of 
back (text fig. I); jaws without teeth Family Bufonidae 
21. Cranial crests absent (text fig. 00). 
22. Head thick through, skin roughly tubercular; head-and-body 
length up to 120 mm. 
23. Parotoid glands nearly as wide as long, and space between 
the two about equal to width of one gland (text fig. OO; pi. 
17, fig. 51, right) Bufo canorus 182 
23'. Parotoid glands longer than wide, space between them 
usually wider than width of one gland. 
24. Back either dark and unspotted, or blotched and speckled 
between the blotches with small, dark dots on the light 
background; spread of hind foot from end of first toe to 
tip of fifth toe usually more than 36% of head-and-body 
length; maximum length 120 mm Bufo boreas boreas 167 
24'. Back usually spotted or blotched (rarely with dark speckles 
between the blotches on the light background) and seldom 
wholly dark; spread of hind foot usually less than 36% of 
head-and-body length; maximum length 110 mm 
Bufo boreas halophilus 169 
22'. Head thin through; skin evenly tubercular; head-and-body 
length under 75 mm Bufo punctatus 192 
21'. Cranial crests present on head (text fig. I). 
25. Cranial crests curved around eyes; large raised glands present 
on tibia (pi. 12, fig. 32) Bufo alvarius 163 
25'. Cranial crests extending backwards in more or less straight 
lines, not curved (pi. 11, fig. 31). 
26. Parotoid glands short and broad; skin smoother, warts on 
back smaller, not closely surrounded by black (pi. 11, 
fig. 31a). 
