56 U.S. NATIONAL MUSEUM BULLETIN 288 



equal to one-fourth its own diameter. Fingers long, with lateral 

 ridges and small terminal disks, free, first finger much longer than 

 second and equal to third, second and fourth subequal and reaching 

 base of penultimate phalanx of third; an oval thumb pad present; a 

 large rounded palmar callus; metacarpal tubercles well developed. 

 Toes fairly long, slightly (about one-eighth) webbed, and their disks 

 small, third toe much longer than fifth, disk of third reaching to base 

 of antepenidtimate phalanx of fourth; a small round metatarsal 

 tubercle and an outer one of equal size; a small tubercle on tarsus 

 midway to heel; no apparent tarsal ridge; a heavy skinfold on heel 

 and knee. Body elongate, in postaxillary region less than greatest 

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

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

 hind legs are bent at right angles to body, heels are narrowly sep- 

 arated. Skin of upper parts rather easily torn, smooth (faintly pustular 

 under the lens) ; venter smooth ; a distinct glandular dorsolateral 

 ridge from posterior corner of eye, above tympanum, ending at groin, 

 and another such ridge below it, both following the light longitudinal 

 stripes; a skinfold across the chest; a weak ventral disk; a pair of 

 lateral external vocal sacs in the male. 



Dimensions. — Head and body, 18 mm.; head length, 7 mm.; head 

 width, 6.5 mm.; femur, 7.5 mm.; tibia, 8.5 mm.; foot, 6.5 mm.; hand, 

 5 mm. 



Color in alcohol. — Dorsum immaculate Mars brown; a white (yellow 

 in life) dorsolateral longitudinal line commencing behind eye and 

 extending straight back to the upper part of the groin, where it 

 merges with the light buff upper surface of the femur; a clove brown 

 band beginning at tip of snout, continuing on loreal region, widening 

 behind the eye and along the side to groin; a light stripe along upper 

 lip; venter, including chin and chest, immaculate pale olive-buff, 

 with a wavy but sharp demarcation between it and the clove brown 

 lateral band; upper part of femur pale, nearly immaculate; posterior 

 femur buff, with a large oval sepia spot from its midpoint to behind 

 the knee, and with a few lighter spots behind anus and extending 

 along lower femur to knee; upper part of tibia, foot, and forearm 

 pale wood brown with darker bars and spots; soles and palms drab 

 with indistinct darker marblings. 



Remarks. — The validity of this species is still doubtful, as further 

 observations on the significance of direction in the light lateral 

 stripe are needed. Most examples of Phyllobates that could be related 

 to P. pratti have this stripe dropping diagonally across the side to the 

 lower part of the groin, but a few frogs, resembling the examples of 

 pratti from the British Museum, have this stripe going straight back 

 from above the shoulder so that it ends above the hind leg insertion. 



