PREFACE. XV 



It is now my duty to acknowledge the assistance which has been so 

 kindly rendered by the eminent specialists Avho have examined these 

 collections ; ^ and, whilst thanking all, I should very especially thank 

 my old friends Mr. H. W. Bates and Professor T. CI. Bonney. Besides 

 the important contributions from the pen of Mr. Bates, I am greatly 

 indebted to him for having acted throughout as my entomological 

 adviser. The extensive series of rocks which was brought home has 

 been carefully and thoroughly investigated by Professor Bonney, but 

 it is thought sufficient to present in this volume only a few general 

 remarks, as his observations have already been published in full in the 

 Proceedings of the Royal Society. 



Amongst my friends in Ecuador who have rendered assistance, I 

 should particularly mention and thank Mr. G. Chambers, British 

 Consul at Guayacpiil, for the snakes which he presented from that 

 locality. At Chillo, I received valuable aid from a sharp little English 

 lad. Master "Willie Slater, who volunteered to collect for me in a 

 district which I was obliged to leave too soon. His diligence was 

 rewarded by obtaining several of the species which are here first 

 described. In Quito, help was rendered by a highly-intelligent Swede 

 (to whom I had been recommended by Baron de Thielmann), Ludwig 

 by name, and through him I acquired the greater part of the collec- 

 tions which come from Milligalli, Tanti, and other places in the West 

 of Ecuador — a region Avhich there was no time to visit. 



Lastly, my most sincere thanks are due to my two assistants, Jean- 

 Antoine and Louis Carrel, for their zeal and industry upon all occa- 

 sions. Our altitudes were determined by mercurial barometers, and 

 the laborious duty of transporting these instruments devolved upon 

 J. -A. Carrel. In consequence of his extreme care, no breakages 

 occurred; and the heights of the localities which are mentioned 

 throughout this volume are accordingly fixed with a degree of 



' The authors are solely responsible for their respective contributions. The wliole 

 of the Type Specimens of the Insects remain in the possession of the authors of tlie 

 papers ; and those of tlie Reptiles and Frogs have been acquired by the Biitish 

 (Natural History) Museum. 



