vi. PREFACE. 



It is, I suppose, inevitable that, as the pursuit of 

 science becomes more widely spread, and investigations 

 more exact, alterations should be made in the nomen- 

 clature and classification of the various species. Such 

 changes, however, add immensely to the difficulty of 

 compiling a catalogue. In the nomenclature adopted 

 throughout these pages, I have to thank Professor Sir 

 William Flower, Director of the British Museum, 

 Natural History, at South Kensington, for valuable 

 assistance with the Carnivora, Rodentia, and Rumi- 

 nantia. In the orders Cetacea and Pinnepedia, I have 

 followed the authors of Bell's British Quadrupeds 

 (1874), and Mr. Thomas Southwell in his Seals and 

 Whales of the British Seas (Norwich, 1881). To him 

 also my thanks are due. The late Mr. G. E. Dobson, 

 F.R.S., having been the recognised authority for 

 Chiroptera and Insectivora, I have adopted the 

 nomenclature of his Catalogue of the Chiroptera 

 (1878), and of his Monograph of the Insectivora 



I have to thank Mr. G. A. Boulenger, F.R.S., 

 for kind help in naming the Reptilia and Amphibia in 

 accordance with the methods adopted by the author- 

 ities of the British Museum. 



Essex fishes have been so little investigated by 

 Essex naturalists that it is certain numerous species 

 must be omitted from a catalogue compiled, as this to 



