12 Records of the Indian Museum. [Vol. Ill, 



different parts of any town show very great variation in these minor 

 points ; at the same time it must be admitted that a few rats 

 caught in a single house, will .often show striking similarity to one 

 another as regards these details. 



The Mole-Rats. 



When the mole-rats and bandicoots of India were first exam- 

 ined by naturalists, the different groups among them received such 

 names as Miis kok, Arvicola hengalensis, Nesokia indica, Mus 

 plurimammis , Mus gigantcus, Mus handicota. In 1878 J. Anderson 

 [10] united them as a sub-genus of Mus under the name Mus 

 (Nesokia), and pointed out the indisputable fact that the group 

 could be subdivided into three series. In 1907 O. Thomas [5] 

 applied a separate generic name to each of these three series, 

 viz. — 



Nesokia for mole-rats which have a short palatine foramen, 



a tail which is only about 50 % of the head and body 



length, and few mammae, 

 Gunomys for mole-rats which have a long palatine foramen, 



a tail which is about 80 % of the head and body length, 



and a continuous row of teats from the axilla to the 



inguinal region. 

 Bandicota for the very large, coarse-furred rats known as 



" bandicoots," which have a relatively longer skull than 



the others, a tail nearly equal to the head and body 



length, and relatively large feet. 

 Anyone who examines large numbers of these rats must 

 recognise the marked discontinuity between the three groups, and 

 the only objection that can be brought against their receiving 

 generic rank is, that there is no greater difference between them 

 than there is between other groups of small rodents which receive 

 merely specific rank. For example, the difference between a 

 Gunomys and a Nesokia seems even less, it is certainly not greater, 

 than the difference between Mus rattus and Mus mettada. In spite 

 of this objection the triple generic nomenclature is used here. 



Gunomys [Nesokia hengalensis) has been received from the 

 Punjab, Calcutta, Rangoon, Madras, Simla, Nepal and other 

 places. 



Nesokia {Nesokia hardwickei) only from Quetta and the 

 Punjab. 



Bandicota from Madras, Bengal and Nepal. 



Although a large number of specimens from any one place 

 always show considerable variation among themselves, there are 

 noticeable differences between the races from several of the 

 places. As these differences seem to be approximately equivalent 

 to those which separate the races of mankind inhabiting the same 

 regions, they have not been considered of sufficient weight to 

 justify the application of specific names. Current literature shows 

 that to honour local races with specific names is becoming a 



