MEXICAN TAILLESS AMPHIBIANS 93 



dular folds present; upper surfaces of thighs with scattered 

 tubercles like back; underparts smooth; inferior surfaces of 

 thighs granular; discoidal abdominal fold present; head-and- 



body length, 25 mm beatae (p. 104) 



No white streak edged with black along upper lip 2 



2. Loreal region oblique, shelving outward to edge of upper jaw; 



either an intratympanic or postcephalic dermal fold; a large 



abdominal disk 3 



Loreal region not shelving outward to edge of upper jaw; neither 



an intratympanic nor a postcephalic dermal fold 4 



3. A distinct sharp-edged tarsal fold; tarsal-metatarsal joint to tip 



of fourth toe, 36 mm.; a large protuberant inner and a very 

 small outer metatarsal tubercle; subarticular tubercles at ends 

 of metapodials fairly large; a few small supernumerary tuber- 

 cles on metatarsals; toes webbed at base; the hind limb being 

 carried forward along the body, the tibio-tarsal joint reaches 

 between eye and nostril; first finger exceeds second by length 

 of its apical disk; large subarticular tubercles and palmer cal- 

 losities; fingers and toes with blunt apical disks; fingers with- 

 out web at base; head thick, remarkably wide, its transverse 

 diameter being one-fifth greater than its length; muzzle obtuse 

 and rounded; canthus rostralis rounded; tympanum large, 

 higher than wide, overhung by prominent dermal fold extending 

 from eye to angle of lower jaw, where one of its two branches 

 goes to shoulder and the other to insertion of fore limb; 

 vomerine teeth in two short oblique clusters, considerably be- 

 hind but within level of inner margins of choanae; tongue broad 

 and somewhat oval in outline; skin on throat, abdomen, and 

 under surfaces of thighs smooth; posterior surfaces of thighs 

 granulated; a transverse post-tympanic dorsal dermal fold; 

 skin of upperparts somewhat shagreen; general tint of upper- 

 parts dark greenish brown; loreal region and tympanum black; 

 hind limbs with black transverse bars; soles of feet black; un- 

 der surface of forearm black; underparts yellowish white; outer 

 margins of throat and under surfaces of thighs and tibiae mar- 

 bled with brown specks; sides finely marbled with brown; 



head-and-body length, 74 mm laticeps (p. 106) 



No tarsal fold; tarsal-metatarsal joint to tip of fourth toe, 28 

 mm.; inner and outer metatarsal tubercles large, the inner 

 elongated and swollen, the outer broad and flattened, and in 

 addition the outer metatarsal tubercle is nearly as large as the 

 inner; large subarticular tubercles at ends of metapodials; feet 

 with numerous supernumerary tubercles on plantar surface; 

 toes free from web at base and without marginal dermal 

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

 the tibio-tarsal joint reaches to center or to anterior margin of 

 eye; heels touch but do not overlap when legs are placed trans- 

 verse to axis of body; first finger exceeds the second by length 

 of its apical disk; fingers long and slender, with terminal 

 T-shaped phalanges; apical disks blunt, swollen inferiorly; two 

 large palmar callosities, the external one divided by a longi- 

 tudinal groove; head much wider than long, with large eyes 

 widely separated; canthus rostralis fairly distinct; muzzle 

 truncate; width of upper eyelid one-half to three-fifths that of 



66785—32 7 



