MEXICAN TAILLESS AMPHIBIANS 95 



generally smooth, but hinder half of belly may be faintly areo- 

 late; under surface of thighs granular; color of upperparts and 

 sides grayish or brownish, mottled and speckled with blackish 

 or grayish; occasionallj' with a narrow interorbital black band 

 and a narrow preorbital transverse black bar on light-colored 

 snout; a narrow dark chevronlike mark with apex pointed 

 inward on each shoulder; one or more pairs of narrow longitu- 

 dinal mid-dorsal markings; a narrow black stripe from posterior 

 edge of eye to above tympanum and downward behind latter 

 nearly to rictus oris; upper lip and loreal region with continuous 

 or discontinuous oblique dark bars; fore and hind limbs cross- 

 barred; under surfaces either uniformly white or throat mar- 

 bled with brownish; head-and-body length, 50 mm alfredi (p. 99) 



Terminal disks of fingers 2, 3, and 4 almost twice the width of 

 corresponding digit, rounded, but their diameter is less than 

 diameter of tympanum; first finger with tip scarcely if at all 

 dilated; subarticular tubercles at ends of metapodials; toes 

 with vestigial web at base; third toe as long as fifth; terminal 

 disks of toes smaller than those of fingers and truncated 

 distally; no supernumerary tubercles on plantar surface; inner 

 and outer metatarsal tubercles rather small and flat; tarsal fold 

 present; the hind limb being carried forward along the body, 

 the tibio-tarsal joint reaches to or beyond the tip of the snout; 

 vomerine teeth in two small round groups well behind and 

 within level of inner margins of choanae; tongue large, sub- 

 circular; canthus rostralis distinct; loreal region oblique and 

 slightly concave; diameter of tympanum less than half that 

 of eye; skin of upperparts smooth; underparts, sides, and 

 lower surfaces of thighs coarsely granular or areolate; upper- 

 parts brownish with triangular interorbital black spot extend- 

 ing laterally on eyelids, a transverse black band across shoul- 

 ders, and six or more large irregular black spots on back; fore 

 and hind limbs with broad dark cross bands, or else with orna- 

 mental markings obliterated or merging into the dark brown 

 or almost black ground color; underparts lighter brown or 

 yellov/, with fine black specks on throat and belly; head-and- 

 body length, 38 mm longipes (p. 107) 



Toes united at base by vestigial web, with obvious marginal der- 

 mal fringes extending to terminal disks; web at base of toes 

 extends to or a little beyond basal subarticular tubercle; 

 marginal dermal fringes extend to terminal disks; toes in 

 order of decreasing length, 4, 3, 5, 2, and 1; fifth toe reach- 

 ing to terminal disk of third; two metatarsal tubercles, the 

 inner large and elongated, the outer small and indistinct; 

 a distinct tarsal fold; no supernumerary tubercles on plantar 

 surface; disks of toes distinct, those of 2, 3, and 4 most 

 noticeably dilated; first finger either shorter than or slightly 

 longer than second; terminal disks of fingers distinct, but 

 not noticeably enlarged; subarticular tubercles not contin- 

 ued backward on palmar surface; two palmar callosities, the 

 inner large and elongate, the outer flattened and usually 

 divided by longitudinal groove; the hind limb being carried 

 forward along the body, the tibio-tarsal joint reaches at least 

 to between eye and nostril and at most beyond end of snout; 

 vomerine teeth in two nearly transverse groups, behind and 



