MEXICAN TAILLESS AMPHIBIANS 97 



joint reaches beyond the end of the snout; vomerine teeth 

 in two small rounded groups behind the choanae, well sepa- 

 rated from each other, and not extending outward beyond 

 level of inner margins of choanae; tongue subround, scarcely 

 or not notched behind; canthus rostralis distinct; loreal region 

 subvertical; head with flat crown and subacuminate snout; 

 tympanum round, one-half, three-fourths, or even equivalent 

 to diameter of eye; skin of upperparts smooth, with excep- 

 tion of a pair of undulating, anteriorly bifurcating linear dermal 

 folds; upper surface of head smooth, with a few indistinct 

 tubercles on upper eyelid; legs and underparts smooth; no 

 dermal fold across chest; head-and-body length, 35 mm-_venustus (p. 117) 

 No broad longitudinal dark-colored band bounded laterally by 

 converging dermal folds; a black stripe runs from nostril along 

 canthus rostralis through eye to above tympanum, decurving 



behind the latter; plantar surface often black or dark colored 8 



Skin of upperparts finely granular, with scattered tubercles; a 

 faintly defined granular vertebral dermal ridge; skin of under- 

 parts smooth or with hinder half of belly areolate; thighs 

 heavily granulate; canthus rostralis fairly distinct; loreal 

 region subvertical; upper eyelid narrower than interorbital 

 space; tympanum large, round, considerably more than half 

 diameter of eye, its distance from eye being just over one-half 

 of its own diameter; vomerine teeth in two short heavy 

 oblique series some distance behind the choanae, the interval 

 between them being less than distance from outer end of each 

 one and corresponding choana; first finger slightly longer 

 than or subequal with second; fingers with small ball-like 

 terminal disks; subarticular tubercles on palmar surface, as 

 well as on digits; toes with more flattened and less ball-like 

 terminal disks; two metatarsal tubercles, the outer one small, 

 round, and conical, the inner one oblong and large; a rather 

 indistinct tarsal fold; the hind limb being carried forward 

 along the body, the tibio-tarsal joint reaches beyond the tip 

 of the snout; upperparts lichen gray, rather smoky, with 

 minute black spots scattered over head and back; grayish fore 

 and hind limbs with indistinct darker cross bands; a black 

 streak curves around tympanum from eye to above insertion of 

 fore limb; three subvertical dark brown bars, separated by 

 narrower light spaces, extend across lower and upper lips to 

 eye and loreal region; a pair of dark spots on end of snout in 



front of nostrils; head-and-body length, 35 mm dunnii (p. 105) 



Skin of upperparts either areolate or smooth, occasionally with 



scattered or sparsely placed tubercles; 9 



A tarsal fold or a crested tubercle 2 or 3 mm. above inner meta- 

 tarsal tubercle generally present; skin of belly either areolate 

 or smooth; throat smooth; under surface of thighs granular; 

 skin of upperparts areolate or apparently smooth, but with tiny 

 asperities; several exceedingly fine dermal ridges generally 

 present, the longest of which extends along vertebral column 

 from snout to vent; one from eye above tympanum to shoulder 

 and thence along side; another oblique one extending from eye 

 toward center of back and thence backward and outward to 

 point where sacral diapophysis juts out, which together with 

 corresponding one on opposite side incloses an hourglass-shaped 



