V1 INTRODUCTION. 
Mr. G. C. Champion, who collected Reptiles in Guatemala and the State of Panama, 
and to whom we are indebted for some important specimens from Chiriqui; and from 
Mr. H. Rogers and Mr. C. F. Underwood, who largely collected Reptiles and 
Batrachians in various localities in Costa Rica (Irazu, Rio Sucio, La Palma, the neigh- 
bourhood of San José, &c.). 
All these collections yielded new or valuable material, extending our knowledge of 
the species and of their range; but also clearly showing that, so far as Reptiles and 
Batrachians are concerned, our information is not nearly so extensive as it is in the 
case of the Birds and certain orders of Insects. The collections contained some of the 
forms described by Cope, Bocourt, Brocchi, and others (as well as many unknown to 
those herpetologists), but a large proportion, perhaps the majority, continued to be 
known to me from descriptions only. In fact, the districts whose Reptilian fauna is 
satisfactorily kuown are but few in number, our acquaintance with them being chiefly 
due to the labours of Naturalists who have resided in the country for a lengthened 
period, and who have devoted themselves specially to this branch of study. From 
among them I must mention the late F. Sumichrast, who thoroughly explored the 
Reptilian Fauna of the Isthmus of Tehuantepec; Dr. A. Dugés, of Guanajuato, who 
not only published numerous papers on the Reptiles of his district, but also supplied 
Cope and the Paris Museum with a complete series of the species observed by him ; 
the late A. Sallé and A. Boucard, who collected for many years in the country round 
Oaxaca, Orizaba, and Vera Cruz; O. Salvin, who paid three visits to Guatemala, 
collecting chiefly in the neighbourhood of Antigua and in Alta Vera Paz. Perhaps no 
other part of Central America is better known than the plateau and highlands round 
Mexico city, whence numerous collections have reached Europe ; and the Republic of 
Costa Rica, whose Government has done so much for the physical exploration of the 
country. The Reptiles of the latter region have formed the subject of important 
contributions by Cope and Peters, and collections more recently received through 
the liberality of the authorities of the Museo Nacional de Costa Rica, at San José, 
and of M. Pittier de Fahéga, have considerably added to our knowledge of this 
Fauna. 
According to the general plan laid down by the Editors of the ‘Biologia,’ descriptive 
diagnoses were to be given of those species only which had not been satisfactorily 
described elsewhere. I have followed this plan throughout the part treating of 
Reptilia, but I thought it better to depart from it in the Batrachian portion of the 
