CLASSIFICATION O 



The following condensed citations of the place of the original 

 descriptions — with some of the associated references — serve to 

 give a brief history of the nomenclature. 



MUS, Linnaeus, 1758 

 EPIMYS, Trouessart, 1881— Miller, 1910. 

 RATTUS, Fischer, 1803— HoUister, 1916. 



— norvegicus, Erxleben (1777 descr. orig.) 

 ^decumanus, Pallas (1778) 



— aquaticus, Gessner, 1551. 



Cosmopolita; ab Asia Occident, in Europam a navibus translat. et 

 inde in omnes Orbis Regiones. 

 ^rattus, Linnaeus (1758 descr. orig.) 



Cosmopolita; ab Asia Occident., in Europam a navibus trans- 

 lat., et inde in omnes orbis regiones. 

 — alexandrinus, Geoffroy, (1812 (or 1829 vide Sherborn, 1897) descr. 

 orig.) 



Asia minori, Arabia, Aegyptus, Algeria, etc. 

 Italia, Hispania, Gallia merid. — orient, et occid., et inde in om- 

 nes orbis regiones. 



Since attention was called to Erxleben's description in 1777 

 (Rehn, 1900) his specific name, norvegicus, as the designation 

 for the common brown or Norway rat, has been used in place 

 of decumanus (Pallas, 1778). The designation norvegicus is 

 now well established and will be used here. 



There seems no question that Mus rattus and Mus r. alexan- 

 drinus are related to one another as color varieties of the same 

 species (de I'lsle, 1865; Millais, '05) and they are so considered 

 in the follow^ing pages. For convenience we shall use the term 

 Norway or Norway rat for Mus norvegicus — and the term 

 House rat as a general designation for both Mus rattus rattus 

 and M. rattus alexandrinus unless the occasion calls for the 

 precise name. 



Albinos of the house rat have without doubt existed in the 

 w^est of Europe at one time or another ever since this form over- 

 ran that region (Topsell, 1658) but, despite earher reports to 

 the contrary, neither Albino nor pied specimens of the house 

 rat are to be found in our larger museums. 



At present Albinos of the house rat appear to be not uncom- 

 mon in India (Lloyd, '12) where the house rat population is 



