_Remarks._--This species has been confused with _Smilisca sordida_; most authors have referred both species to _Hyla (Smilisca) gabbi_. Examination of the types of _Hyla sordida_, _gabbi_, _salvini_, and _nigripes_ revealed that all of the names were referable to a single species (_S. sordida_), and that the small, blunt-snouted species in Panama and southern Costa Rica probably was without a name. Possibly _Hyla molitor_ Schmidt (1857) is based on the species that we have named _S. sila_, but several discrepancies in his description, plus the unknown provenance of the type, have led us to discount the applicability of that name to the species under consideration. _Distribution._--_Smilisca sila_ ranges along the Pacific slopes and lowlands of southern Costa Rica and Panama at elevations from sea level to about 1300 meters; in northern South America the species occurs in the Caribbean lowlands and in the valleys of the northward draining rivers of Colombia (Fig. 3). _Specimens examined_, 234, as follows: COSTA RICA: =Puntarenas=: 6 km. E Golfito, KU 91717; Quebrada Boruca, 22 km. E Palmar Norte, KU 64265-6; Rio Zapote, 7 km. E Palmar Norte, USC 7100 (2). =San Jose=: San Isidro el General, KU 28200; 14 km. NW San Isidro el General, USC 7098 (2); 15 km. WSW San Isidro el General, USC 7097. PANAMA: =Canal Zone=: Barro Colorado Island, AMNH 62320-3, CNHM 13324, 13326-8, 13330, 13338, 13359, 13423-5, KU 80460-6, 80619 (young), 80625 (skeleton), UMMZ 63542-6, USC 7051. =Chiriqui=: Boquete, AMNH 69815, UMMZ 58441-5; El Volcan, KU 77413, 91828-31 (skeletons), 91852-74, 91832 (eggs), 91833 (tadpoles); 6 km. S El Volcan, CNHM 60442; 16 km. NNW El Volcan, KU 91879-90; Finca Palosanto, 6 km. WNW El Volcan, KU 77406-12, 77692 (skeleton), 91875-7, 92330-1; Rio Colorado, 17 km. NNW El Volcan, KU 91878, 92332; Valle Hornito, 19 km. NE Gualaca, KU 92333-45. =Cocle=: El Valle, AMNH 55440-5 (13), 59607-14, CNHM 48140, 60349-2, 60387-92, 60401-4, 60443, 67842-5, KU 91834 (young), 91902-4, TNHC 23751-2, USNM 140653. =Colon=: Rio Candelaria, AMNH 53708-15, CNHM 67826-36. =Darien=: Camp Creek, Camp Townsend, AMNH 40756-7, 40936-9, 40992; Rio Chico, AMNH 39784, 40986-7; Rio Pita, CNHM 67823-5; Tacarcuna, USNM 141796-802; Three Falls Creek, AMNH 41684, 51788. =Los Santos=: Cerro Hoya, USNM 148213-4; Lajamina, Rio Puria, KU 67915. =Panama=: Altos de Pacora, KU 91894; Cerro Jefe, KU 91895-6; Cerro La Campana, CNHM 67846, KU 91897-900, USNM 139689; Finca La Sumbadora, KU 80467-81, 80620 (tadpoles), 91910 (eggs), 91911-2 (tadpoles), 91913 (young), 91908-9 (skeletons); Rio Calobra, USNM 53722, Rio Pacora, 9 km. NNE Pacora, KU 91901. =Veraguas=: Cerro Carbunco, USNM 129066; Cerro Tute, CNHM 67837-41; Isla Cebaco, Rio Platanal, KU 91891-3. COLOMBIA: =Antioquia=: Uraba, Villa Arteaga, CNHM 63893 (Goin). =Atlantico=: Sabanalarga, Rio Causa, AMNH 14506. =Smilisca sordida= (Peters), new combination