456 u - s - NATIONAL MUSEUM BULLETIN 2 88 



inner metatarsal tubercle and a smaller round outer one; a pro- 

 nounced inner tarsal ridge, ending near heel; a series of distinct 

 skinfolds on heel and knee. Body stout, in postaxillary region a little 

 narrower than greatest width of head. When hind leg is adpressed, 

 heel reaches posterior border of eye; when limbs are laid along the 

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

 to body, heels overlap considerably. Skin of upper parts smooth 

 (pustular under the lens, especially on sacrum and around venter); 

 venter smooth, with a few faint transverse glandular ridges on pos- 

 terior belly; a heavy glandular ridge from posterior corner of eye 

 above tympanum, ending behind commissure of mouth, where it 

 joins a very short ridge emanating from corner of mouth; a skinfold 

 across chest; a ventral disk; external vocal sacs in the male. 



Dimensions. — Head and body, 63 mm.; head length, 19.5 mm.; 

 head width, 23.5 mm.; femur, 30.5 mm.; tibia, 28 mm.; foot, 27 mm.; 

 hand, 15.5 mm. 



Color in alcohol. — Dorsum drab, darkening to mouse gray on sac- 

 rum; a wide olive buff bar across head extending onto anterior half of 

 upper eyelids, followed by a sepia bar; top of snout in front of eyes 

 sepia; an indistinct sepia bar across back above shoulders; legs wood 

 brown, femur with four or five rather narrow dark sepia crossbars, the 

 tibia with three such bars, the middle one widest, and a few sepia bars 

 across side of foot; a clove brown stripe along inferior border of dorso- 

 lateral folds; posterior femur and inside of tibia clove brown to black, 

 with numerous small round white spots; groin clove brown spotted 

 with white, an anterior prolongation of this pattern extending for- 

 ward on side halfway to axilla; side of head olive buff to cream buff, 

 with a wide dark brown band along edge of lip, and with a narrow line 

 of cream buff extending beyond commissure of mouth and ending on 

 shoulder; venter burnt umber to sepia anteriorly, with many small 

 round cream buff spots; posterior half of belly and lower leg surfaces 

 buff, with a few small drab dots towards the knee and on top of foot. 



Remarks. — Rivero (1961, p. 38) has expressed doubt that AMNH 

 39791 from Vaupes is a member of this species. We agree with Rivero 

 in that this frog is not mystaceus, which has the light, upper-lip line 

 continuous from the tip of the snout to the shoulder, while AMNH 

 39791 has a spotted lip in front of the eye, the light stripe being obvious 

 only from below the eye to the shoulder. Furthermore, mystaceus has 

 an immaculate light venter (except for a few darker spots on lower 

 lips and throat in an occasional example) while AMNH 39791 has a 

 heavy brown reticulation on the venter. 



More examples of rhodomystax from Colombia are needed before 

 precise variations in color and body structure of these frogs can be 

 determined. 



