Atelopus petersi Atelopus petersi Atelopus petersi is a species of toads in the family Bufonidae. It is endemic to Ecuador and is known from the Cordillera Oriental in the Napo Province and more provisionally, in the Chimborazo Province. The specific name "petersi" honors James A. Peters, an American zoologist who collected the first specimens of this species in 1962 and provided a description under the name "Atelopus pachydermus". Common names Peters' stubfoot toad and Peters' jambato toad have been coined for it. Adult males measure and adult females in snout–vent length. The snout is acuminate. The tympanic membrane, annulus, and stapes are
Semipermeable membrane the rate and the permeability. Many natural and synthetic materials thicker than a membrane are also semipermeable. One example of this is the thin film on the inside of the egg. Note that a semipermeable membrane is not the same as a selectively permeable membrane. Semipermeable membrane describes a membrane that allows some particles to pass through (by size), whereas the selectively permeable membrane "chooses" what passes through (size is not a factor). An example of a biological semi-permeable membrane is the lipid bilayer, on which is based on the plasma membrane that surrounds all biological cells. A group of