IIO Records of the Indian Museum. [VoL. V, 
Naini Tal, it was difficult to obtain the rats in large numbers , this 
state of things was a cause of error in one direction. The previous 
conclusions may be summarized as follows :— 
(1) The rats of Naini Tal differ from those of the plains in the 
following respects :— ; 
(a) they have on the average shorter tails ; 
(b) their fur is longer and more plentiful and is of a greyer 
Bhat 
(c) they are white-bellied, but a few of them are not quite 
pure in this respect ; in most of them every hair of 
the ventral surface is white in its whole length, as 
is usually the case in white-bellied rats ; but in 
a few of them the ventral hairs are light grey as 
regards the proximal half. 
(2) A-special class of rats was discovered in ten specimens which 
were caught in some adjacent buildings on Ayapata 
Hill. These are exactly the same as the others except 
as regards the colour of the tail. The tail of a rat is 
usually pigmented in its whole circumference, but in 
these the lower surface is pure white and devoid of all 
pigment, the upper surface is deeply pigmented in a 
variable area, in only one of them did it extend to the 
tip, inthe others it extended to the middle of the length 
of the tail, in others not quite so far as this point, while 
in others it extended beyond it. 
A second and more thorough investigation of the Naini Tal 
rats amply confirmed these first impressions, but showed that the 
range of the Ayapata race was much more extensive than was 
at first supposed ; but there is no doubt of the distinction between 
the two classes, nor is there any doubt that the distinction lies 
only in the colour of the tail. The enquiry into the relative 
distribution of the common or black-tailed class and the Ayapata 
class with the bicolored tails, which was carried out in May of 
last year, will now be dealt with. The result may be summarized 
as follows :— 
(1) Any one house contains rats of one or other kind, not 
of both; there is one exception to this rule in the 
case of the house, Dalhousie Villa. 
(2) The largest masses of buildings, such as the bazaars 
and shops which are situated at either end of the 
lake, contain black-tailed rats. 
(3) Isolated buildings distant from and above the level of 
the lake generally contain white-tailed rats. 
(4) But two buildings which are separated from one another 
by a few yards only may contain rats of the different 
kinds. 
