^g'fL ^^3. COMP. ZOOU OCCASIONAL PAPERS of the JUL 8 t.Q74 MUSEUM OF NATURAL Hl^CFOsj^^ The University of Kansas ^^^^Ef^Sirv: Lawrence, Kansas NUMBER 26, PAGES 1-6 JUNE 17, 1974 DESCRIPTION OF A NEW SPECIES OF MICROHYLID FROG, CHIASMOCLEIS, FROM ECUADOR By Charles F. Walker^ and William E. Duellman" Seven specimens of a small microhylid frog were obtained in Amazonian Ecuador in 1972. Although these frogs possess a suite of internal and external characters distinctly different from other known American microhylids, they clearly seem to be allied with certain species currently placed in the genus Chiasmocleis. The new species is characterized by extensive webbing between the toes; in allusion to the duck-like feet, we propose that the frog be named Chiasmocleis anatipes new species Holotype. — University of Kansas Museum of Natural History (KU) 146035, an adult male, from Santa Cecilia, 340 m., Provincia Napo, Ecuador, collected on 2 April 1972 by Martha L. Crump. Paratopotypes.—K\] 146034, 146036 (cleared and stained), 146037-38 obtained with the holotype; 146039 collected by Martha L. Crump on 4 x^pril 1972; University of Michigan Museum of Zoology (UMxMZ) 132897 collected by Martha L. Crump on 19 April 1973. Diagnosis. — Chiasmocleis anatipes differs from its congeners and all otlier known American species of microhylids by having the toes webbed to the bases of the terminal phalanges of each digit. Within Chiasmocleis this amount of webbing is approached only in C. leii-costicta, in which the penultimate phalange of the third toe and the penultimate and antepenultimate phalanges of the fourth toe are free of webbing. ^ Curator, Division of Herpetology, Museum of Zoology, University of Mich-igan, Ann Arbor, Michigan 48104. " Curator, Division of Heipetology, Museum of Natural History, and Pro-fessor, Department of Systematics and Ecology, University of Kansas, Lawrence, Kansas 66045.