On Two Subspecies of the Arctic Fox. 287 



posterior margins, and a dorsal papilla, which is 

 sometimes median-dorsal and sometimes more or 

 less closely approximated to the anterior papilla. 

 *5. Outer blade of jaio loithout accessory minor tooth. 



6. Generative aperture placed immediately behind the 



last pair of legs. 



7. Receptacula seminis present. 



8. Embryos in all stages of development may occur in 



the uteri of one individual. 



III. Afale (peculiar features) : — 



1. Length 15 millira. 



2. Tiventy-tioo pairs of claw- bearing appendages. 



3. Generative aperture placed at the end of a relatively 



long, backvvardly directed, conical papilla, imme- 

 diately behind the last pair of legs. 



IV. 1. The identification of the sex of the individuals with 



22 pairs of legs was confirmed by dissection. 



2. The probability of the constancy of the difference 



in the number of the legs of males and females 

 was strengthened by the examination of the older 

 embryos found in two of the females. 



3. I hope shortly to publish an illustrated account of 



this interestir)g species. 



XLVIII. — On Two Subspecies of the Arctic Fox (Oanis 

 lagopus). By G. E. H. Barrett-Hamilton and J. L. 



BONHOTE. 



A COMPARISON of a set of Arctic Fox skulls brought back by 

 Barrett-Hamilton from Kamtchatka and tlie Commander 

 Islands with the series already in the British Museum 

 collection has revealed the fact that the skulls of those foxes 

 which inhabit the continent of Europe and Asia (and the 

 Commander Islands) may be distinguished from those of 

 Spitzbergen by their larger size and lesser proportionate 

 breadth. It is therefore necessary, according to the custom 

 now in vogue among naturalists, to distinguish the two sub- 

 species by name, and we propose that the fox from Spitz- 

 bergen should be known as Canis lagopus spitzbergenensis^ 

 subsp. n., while the foxes of the mainland should be desig- 

 nated as Canis lagopus typicus. 



The material at present available seems to establish the 



* Nos. 3 to 5 applj to both sexes. 



