Costa Rican frogs of the genera Centrolebe and Centrolenella

Four species belonging to the genera Centrolene and Centrolenella have been recognized in the Fauna of Costa Rica.These are Centrolene ■prosohlepon (Boettger), Centrolenella pulveratum (Peters), Centrolenella valerioi (Dunn), Centrolenella fleischmanni Boettger.Four forms are described as new in the genus Centrolenella.These are C. spinosa, C. granulosa, C. albomaculata and C. colymbiphyllum, all from Costa Rica.Twenty-five specimens of small, green, hylid frogs taken in Costa^ Rica in the summer of 1947, resolve themselves into a group of species, one of which is referable to the genus Centrolene, since a humeral protuberance is present, and the others to the genus Centrolenella in which the protuberance or hook is absent.One of the species possesses a rudiment of a pollex with a sharp spine usually penetrating the free tip.