6 



those islands were already separated before the arrival of any form 

 of Mammalian life. 



Such a hypothesis of the dispersal of English Mammals through 

 Scotland and Ireland appears to me to be the only one which ex- 

 plains the peculiarities of their present distribution, and is likewise 

 in accord with the facts of physical geography. Should it be 

 accepted, the recent and extinct Mammals of Scotland may be 

 arranged in five categories, in the order of the dates of their im- 

 migration. This I have attempted to show in the following list, 

 in which the extinct species are marked with an asterisk: — 



List of Extinct and Recent Scottish Mammals, arranged in the 

 probable order of their arrival prom the southward. 



I. — Before deposit of boulder-clay : — 

 *1. Elephas primigenim. 



II. — Before separation of Ireland : — 



3. Erinaceus turopaeus. 



4. Sorex minutus. 

 *5. Cants lupus. 



6. G. vulpes. 

 *( Ursus fossilis. )* 



7. Maries sylvestris. 



8. Mustela erminea. 



9. Meles taxus. 

 10. Lutra vulgaris. 



III. — Before separation of Hebrides: — 



19. Sorex tetragonurus (?) 



20. Arvicola agrestis. 



IV. — Before separation of the Orkneys: — 



*2. Rangif&r tarandus. 



*11. Equns cabullus. 



*12. tins scrofa. 



*13. Megactros giganteus. 



14. Cervus elapkus. 



15. Sciurus vulgaris. 



16. Mux sylvestris. 

 Lepus variabilis. 

 L. euniculus. 



17 



18 



*21. Bos longifrons. 



22. Crossopusfodiens. 

 *23. Bos primigenius. 



V. — Since separation of Orkneys: — 

 25. Talpa europaea. 

 20. Felts catus. 

 *27. Ursus arctos. 



28. Mustela vulgaris. 



29. M. putorius. 

 *30. Alces machlis. 



24. Arvicola amphibius. 



Capreolus capraea. 

 Castor Jiber. 

 Mus minutus. 

 Arvicola glareolus. 



31. 



*32. 

 33. 

 34. 

 35. Lepus europaeus. 



I now proceed to the consideration of the details of the distribu- 

 tion of the species, taking first the recent, and second the fossil 

 and extinct forms. 



London, 1880. 



* Remains of the Cave Bear have not yet been found in Scotland, but its former existence is 

 rendered probable by theii presence in Irish deposits. — Cf. A, Leith Adams, loc. cit. 



