264 



C. A. GouRLAY : The Rats of Dacca. 



[Vol. I, 



The following table shows the variations in size and the propor- 

 tionate measurements of M. rattus as found in Dacca. Judging by 

 the breast development in female specimens, it appears that matu- 

 rity is reached when the rat is about 14 cm. in length. Of 53 female 

 specimens under 14 cm. only one was found to have developed 

 breasts. 



An adult M. rattus, then, measures anything from 14 cm. to 

 20 cm. The largest specimens are old males, and are the only 

 specimens with well-developed bristles in the fur. 



The tail is almost always considerably longer than the head and 

 body. The shortest tail in my collection is 102-37 P^'^ cent, of 

 the body-length, and the rat measured 21-5 cm., so that it was a 

 very old specimen. 



Hind foot. — The sole is seldom uniformly purple. There is 

 always some purple towards the " heel," but the fore-part of the 

 sole is generally flesh-coloured. The pads are always six in number, 

 the proximo-external pad being well developed. The median pads 

 are cordiform. 



Ear.— By measurement, the ear does not appear to be appre- 

 ciably longer than that of a Ncsokia bcngalensis of the same size, 

 but the setting is characteristic. The ear is " prominent, standing 

 out clearly from the head." 



Breasts. — In females, the usual distribution of the breasts is f . 

 The most common variation (in G pe cent, of the specimens) is f. 

 When this occurs, the third pectoral breast bears the same relative 

 position to the second pectoral as the third inguinal bears to the 

 second inguinal. The first inguinal breast is about 1-25 cm. in 

 front of the second and the second is about '3 cm. in front of the 

 third. 



