1862. Ueber zwei noch unbeschriebene Batrachier. Arch. Zool. Anat. Fisiol., 2:77-82. 1867. Amphibien. Novara Expedition. Zool. Theil, I, Vienna, 70 pp. TRUEB, L. 1970a. The evolutionary relationships of casque-headed treefrogs with co-ossified skulls (family Hylidae). Univ. Kansas Publ. Mus. Nat. Hist., 18:547-716. 1970b. The generic status of _Hyla siemersi_ Mertens. Herpetologica, 26:254-267. TRUEB, L. and W. E. DUELLMAN 1970. The systematic status and life history of _Hyla verrucigera_ Werner. Copeia (4):601-610. TYLER, M. 1971. The phylogenetic significance of vocal sac structure in hylid frogs. Univ. Kansas Publ. Mus. Nat. Hist., 19:319-360. WERNER, F. 1901. Ueber Reptilien und Batrachier aus Ecuador und Neu-Guinea. Verh. Zool.-Bot. Gesell. Wien, 50:593-614. UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY The University of Kansas Publications, Museum of Natural History, beginning with volume 1 in 1946, was discontinued with volume 20 in 1971. Shorter research papers formerly published in the above series are now published as Occasional Papers, Museum of Natural History. The Miscellaneous Publications, Museum of Natural History, began with number 1 in 1946. Longer research papers are published in that series. Monographs of the Museum of Natural History were initiated in 1970. Institutional libraries interested in exchanging publications may obtain the Occasional Papers and Miscellaneous Publications by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas 66044. Individuals may purchase separate numbers of all series. Prices may be obtained upon request addressed to Publications Secretary, Museum of Natural History, University of Kansas, Lawrence, Kansas 66044. Transcriber's Notes Except for the list of corrections below and minor corrections not listed, the text presented here is that of the original printed version. Typographical Corrections Page Correction ==== ================ 5 is => in 5 buckley => buckleyi 17 scaral => sacral 19 Provicia => Provincia 25 in => is 25 metalic => metallic 41 bromeiad => bromeliad Text Emphasis _Text_ - Italics =Text= - Bold