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



The definition ol such species, however burdensome it may 

 seem, is not in itself fallacious, for a famil}^ group of inbred rats 

 taken from a single house or set of burrows may show definite and 

 measurable peculiarities. By naming these groups specifically one 

 does not directly establish a fallacy. Indirectly, however, the 

 procedure causes false impressions, in the following way. When 

 a new species is discovered in a district, the discovery being based 

 on a few specimens caught together, the idea is originated that 

 many other rats in that district will resemble the type of the new 

 species. This is far from being the case. The species of 

 Himalayan rats illustrate this anomaly. From previous writings 

 the impression is given that Mus jerdoni is a common rat in 

 Darjiling ; that Mus niveiventer is common in Katmandu ; that 

 Mus vicerex [3] is the rat found at Simla. We have received rats 

 from six different parts of Darjiling, none of which resemble M . 

 jerdoni in any way; over fifty rats are from Simla, none of which 

 show the peculiarities of M. vicerex. Rats brought this year 

 from Katmandu have no resemblance to M . niveiventer which was 

 described in 1836 from five rats caught in the Residency of that 

 place. On the other hand, certain rats from Kashmir are very 

 like the type of M. vicerex, judging from the description of it. 

 Certain rats from Naini Tal are equally like M. niveiventer , though 

 one of these was caught in the same cupboard on the same night 

 with a rat which showed features peculiar to M. herdmorei [4], a 

 species only known from Manipur (Assam), and Mergui (Ten- 

 asserim). It seems impossible to reconcile results obtained b}^ 

 studying large numbers of rats with results which have been 

 previously obtained by the study of small numbers of speci- 

 mens. 



Great confusion exists in the nomenclature of Oriental rats. 

 The common mole-rat of India was first regarded as a species of 

 Mus\ later on it was known as Nesokia bengalensis ; quite recently 

 it has become a species of a new genus Gunomys [5]. The antelope 

 rats may be placed in the genera Meriones, Tatera or Gerbillus. 

 vSpecific names which have been long abolished are often revived. 

 As a result of this it is often difficult to determine the scientific 

 names of common rats. 



The following instance may be cjuoted in illustration of this 

 difficulty. The honorary curator of a local museum sent certain 

 field rats to the Indian Museum for identification. They were 

 returned as Nesokia hardwickei and Gerbillus erythura. The sender, 

 being desirous of obtaining the best possible results for his museum, 

 sent similar specimens to Europe; they were returned as Nesokia 

 huttoni and Meriones crytlirura. The Indian ^Museum was informed 

 of this by the curator of the local museum. It cannot, however, 

 be maintained that one pair of names was right and the other 

 wrong. The names given by the Indian Museum for these well- 

 known rats were taken from the Fauna of British India, the 

 author of which upholds the name Gerbillus, and considers that 

 the specific name huttoni is included in hardwickei. 



