120 U. S. NATIONAL MUSEUM BULLETIN 206 



forwards to the lip border when viewed in profile, the upper jaw 

 scarcely projecting beyond the lower; nostrils superolateral, scarcely 

 projecting, their distance from end of snout about three-fourths that 

 from eye. Canthus rostralis scarcely defined; loreal region flat. Eye 

 large and prominent, its diameter equal to its distance from end of 

 snout; interorbital diameter Iji times that of upper eyelid, a little 

 greater than width between nostrils. Tympanum indistinct, only 

 faintly visible as a flattened area beneath skin of side of head, ap- 

 parently about one-half the diameter of eye, separated from eye by a 

 distance equal to about half its own diameter. Fingers a little less 

 than one- third webbed, fourth considerably longer than second, 

 reaching to disk of third, which covers nearly the entire tympanic 

 area; no projecting rudiment of a pollex; toes three-fourths webbed, 

 third and fifth subequal, disk of fourth covering about three-fourths 

 the tympanic area; a distinct small inner but no outer metatarsal 

 tubercle; no distinct raised tarsal fold; no dermal appendage on heel 

 but a faint dermal ridge across it. Body somewhat elongate, in the 

 postaxillary region about equal to greatest width of head; when hind 

 leg is adpressed, heel reaches to nostril; when limbs are laid along the 

 sides, knee and elbow touch; when hind legs are bent at right angles to 

 body, heels considerably overlap. Skin of upper parts very finely 

 glandular, with a few minute pustules on top of head; a rather weak 

 glandular ridge above the tympanic area, soon terminating on the 

 shoulder. Skin of chin smooth, that of throat and chest finely glandu- 

 lar, that of belly and lower femur coarsely granular. A slight skinfold 

 across chest. (An external median vocal sac in the male.) 



Dimensions. — ^USNM 96198 (cotype of H. pallens): Head and bod}'' 

 19 mm.; head length 6.5 mm., width 7 mm.; femur 9 mm.; tibia 10.5 

 mm.; foot 8.5 mm.; hand 5.5 mm. 



Color in alcohol. — Ground color above pale ecru-drab; a darker drab 

 longitudinal hourglass-shaped mark beginning on the head between 

 the eyes, its narrowed part above the arm insertion, and its posterior 

 widened part prolonged outwards and backwards on each side for a 

 short distance ending midway between axilla and groin; a pair of 

 rounded drab spots on the sacral region more or less confluent with 

 the posterior prolongation of the hourglass-shaped mark, and another 

 fainter, smaller pair of round spots behind them ; forearm faintly and 

 tibia distinctly marked with drab crossbands; all drab marks on body 

 and limbs outlined very distinctly with a narrow white line, which 

 appears also along the canthus rostralis and along the outside of 

 tarsus, crossing the heel, and emphasizing the dark area on underside 

 of foot. Femur immaculate. Ventral surface pale ecru drab to pale 

 vinaceous, immaculate. A white line followed by a small dark patch 

 in front of anus. 



