INTRODUCTION. 



The enumeration of the species of the five Families of Orthoptera here dealt with 

 having already extended to 45S pages, with twenty-one Plates, it has been decided to 

 treat the two remaining families, the Acridiidae and the Phasmidae, in a separate 

 volume. All the arrangements for the publication of the present volume have been 

 entirely under the control of Dr. Henri de Saussure, of Geneva, who, on account of 

 his failing eyesight, has been obliged to give up the remainder of the work. 



The Forficulidae have been worked out by Count de Bormans alone. 



The Blattidae and Mantidae by Dr. Henri de Saussure, in collaboration with Dr. Leo 

 Zehntner. 



The Gryllidae by Dr. H. de Saussure alone. 



The Locustidae by Dr. H. de Saussure, with the assistance of M. Alphonse Pictet. 



The Introductory remarks and all the general dissertations on the Blattidae, Mantidae, 

 Gryllidae, and Locustidae have been contributed entirely by Dr. H. de Saussure. In 

 these Families the author has also described, noticed, or figured various allied North- 

 American or Tropical South-American species for comparison, as it is very probable 

 that some of these will eventually be found to inhabit the region under investigation. 

 These species are throughout the work included in square brackets, though for 

 convenience they are numbered consecutively with the others in the text. 



The following is the total number of species enumerated from Central America : — 

 Forficulidae, forty-one, with eight new ; Blattidae, 156, with sixty new ; Mantidae, 

 sixty-one, with thirty-three new ; Gryllidae, 102, with forty-three new; Locustidae, 273, 

 with eighty new. The number of species for the five Families being 633, with 

 224 new. 



The Acridiidae have been undertaken by Professor Lawrence Bruner, of Lincoln, 

 Nebraska, and we hope to commence the publication of Volume II. immediately. 



Ed. 



April 1900. 



