INTRODUCTION. 
In dealing with the multitude of forms of Aglyphodont Colubroids, 
all of comparatively simple structure, the lack of prominent cha- 
racters on which to establish genera is seriously felt, and, but for 
the study of the dentition, satisfactory definitions could not be 
drawn up. I have therefore, as in the previous volume, supplied 
numerous outline-figures of jaws to facilitate the understanding of 
the diagnoses. 
I have endeavoured to avoid both extremes of excessive fusion or 
separation in my attempt to render genera approximately equivalent 
to those of other groups of Reptiles. 
Descriptions of 427 species are given. Of these, 347 are repre- 
sented in the Collection of the Museum, the number of specimens 
amounting to 2528. 
G. A. BOULENGER. 
Zoological Department, 
July 28th, 1894. 
