B R E V,..I,,1)'R a ^Nivk^ro ISlTy MmseiLim of Comparative Zoology us ISSN 0006-9698 Cambridge, Mass. 31 January 1992 Number 494 ON SOME OVERLOOKED SPECIES OF THE GENUS LIOLAEMUS WIEGMANN (REPTILIA TROPIDURIDAE) FROM PERU R. F. Laurent' Abstract. Three new species of the genus Liolaemus, L. robustus, L. polystic-tus, and L. williamsi, from the upper western slopes of the Cordillera Central and of the eastern slopes of the Cordillera Occidental of Peru are described. They were previously confused with L. multiformis Cope, 1856, which is here synonymized with L. signifer (Dumeril and Bibron, 1841) and seems to be restricted to the northern part of the Altiplano. The status of other northern species oi Liolaemus is discussed. INTRODUCTION The bewildering diversity of the genus Liolaemus Wiegmann has been well documented by L. Miiller, W. Hellmich, R. Donoso-Barros, and J. M. Cei for the southern part of its range in Chile and Argentina, more or less south of the 30th parallel. In contrast, this diversity has been largely neglected in the northern part of its range, in northwestern Argentina, Bolivia, and Peru. Many of the forms that occur in this region have been inadequately de-scribed, and a number of names have been placed in synonymy with little or no documentation. Thus, the discovery of three undescribed species from the upper western slopes of the Cor-' Investigador Principal del CONICET, PRHERP-Fundacion Lillo, Miguel Lillo 251, 4000 Tucuman, ARGENTINA.