22 U.S. NATIONAL MUSEUM BULLETIN 2 88 



Dendrobates opisthomelas Boulenger 



Plate 2g-i 



1899. Dendrobates opislhomeleas Boulenger, p. 275, pi. 11, fig. 4 (type locality, 

 Santa Inez, north of Medellin, Antioquia, 3,800 ft., Andes of Co- 

 lombia). — Gorham, 1963, p. 25. 



Description.— USNM 145794 (formerly BM 1947.2.15.30, co- 

 type), an adult from Santa Ines, north of Medellin, Antioquia, 

 Colombia. Tongue relatively large, three-fifths as wide as mouth open- 

 ing, ovate, its posterior border free and unnotched; snout broadly 

 rounded when viewed from above, rounded and sloping backwards 

 in profile, the upper jaw extending well beyond the lower. Nostrils 

 lateral, slightly projecting, their distance from end of snout one- third 

 their distance from eye. Canthus rostralis broadly rounded; loreal 

 region flat, vertical, in line with the vertical upper lip. Eye large, 

 prominent, its diameter a little greater than its distance from tip of 

 snout; interorbital diameter 1% times that of upper eyelid, slightly 

 less than interval between nostrils. Tympanum distinct except on its 

 upper posterior border, its greatest diameter about one-third that of 

 eye, separated from eye by an interval equal to one-third its own 

 diameter. Fingers moderate, with faint lateral ridges, free, first finger 

 much shorter than second, fourth a trifle longer than second, its tip 

 reaching to base of penultimate phalanx of third, the disk of which 

 covers half the tympanum; a small oval thumb pad present; a larger 

 rounded palmar callus; metacarpal tubercles well developed. Toes 

 long, third toe much longer than fifth, its disk reaching just beyond 

 base of antepenultimate phalanx of fourth; disk of fourth toe covering 

 half the tympanum and approximately equal to that of third finger; 

 a small inner metatarsal tubercle and a smaller but equally distinct 

 outer one; no true tarsal ridge, but a diagonal gland midway between 

 heel and inner metatarsal tubercle; a strong skinfold on heel and knee. 

 Body moderate, in postaxillary region a little wider than greatest 

 width of head. When hind leg is adpressed, heel reaches anterior 

 corner of eye; when limbs are laid along the sides, knee and elbow 

 greatly overlap; when hind legs are bent at right angles to body, heels 

 slightly overlap. Skin granular on back and sides, especially so on 

 sacrum; head nearly smooth; belly finely granular; chin and chest 

 smooth; a swelling behind eye, and a distinct glandular ridge begin- 

 ning behind eye and descending behind tympanum, covering its 

 upper posterior rim, ending on shoulder; no skinfold across the chest; 

 a faint ventral disk; apparently no external vocal sacs in the male. 



Dimensions. — Head and body, 18 mm.; head length, 6 mm.; head 

 width, 5.5 mm.; femur, 7.5 mm.; tibia, 8 mm.; foot, 7 mm.; hand, 5.5 

 mm. 



