PREFACE. 
The object of the present Catalogue is to give a complete List of 
all the genera and species of Hemiptera Heteroptera known to 
exist in the collections of European and American Entomologists. 
The letters a, b, c, kc., after the species, denote the specimens now 
contained in the British Museum, followed by the habitat and the 
mode in which each of them was obtained ; and the absence of 
these letters indicates the species which are desiderata, and there- 
fore desirable to be procured for the collection. 
J. E. GRAY. 
British Museum, 
August 1st, 1873. 
