PREFACE. 
PAA 
In the First Edition the object of this ‘ Gnraleene ? was stated to be 
to give a description of the species of Tailless Batrachians in the 
British Museum, with an indication of the history and origin of 
all the specimens in that collection, and also an account of the 
species which were known to exist in other museums but were desi- 
derata in the National collection. ‘This plan has been completely 
carried out in the present edition ; it contains descriptions of, or 
references to, all the species introduced into the literature, whilst 
in the former edition no mention was made of species known from 
imperfect descriptions only. 
The rearrangement of this part of the zoological collections, 
with a new Catalogue, had become very urgent for some time. By 
the First Edition a fresh impulse to the study of Batrachians was 
evidently given, many collectors turning their attention to them 
and discovering a great number of new forms, so tha. the collec- 
tion in the British Museum alone has been nearly tripled within 
the last twenty years. That work fulfilled its purpose, but it has 
also ceased to be a satisfactory guide in the examination and deter- 
mination of these animals. Besides, the discovery of almost every 
new generic type showed that the system proposed in the first 
edition (complete as it was in itself) was artificial, and that the 
employment of certain osteological characters, which had been worked 
out by. Cope, Mivart, and Parker, promised a much more natural 
