various Forms 0/ Arvicantiiis pumilio. 635 



The following- specimens — 



Basilar 



Hind length of Length of 



foot. skull, tooth-row. Bullae. 



3.7.2.22. Y. adult 24 20-5 4-8 6 



3. 7. 2. 24. Y. adult 24 20-5 4-8 6 



3.7.2.27. Y^oung 24 19 4-8 G 



3.7.2.33. Adult 24 21-6 48 6 



— among those taken at Cape Town seem to point to a distinct 

 form having a far shorter head than pumilio. Unfortunately 

 all the specimens are comparatively young. I have given 

 the antero-posterior length of bulla3 in these specimens as 6, 

 but it is, 1 believe, slightly less, though greater than 5*5 ; 

 this measurement is a difficult one to take uniformly^ and I 

 have not dared to record diiferences of less than ^ mm. 

 Should the receipt of more specimens, especially old ones, 

 show later that this is a good form, the name of vittatus, 

 Wagner (Arch. Naturg. viii. 1842, p. 11), is, perhaps, avail- 

 able for it, the name having been based on specimens from 

 the Cape "Promontory'^; till then I fear vittatus must rank 

 as a synonym oi puiniUo. 



Arvicanthis pumilio intermedius, subsp. n. 



2.9.1.62,05, 69-71.") 



3.1.4.52-55. V Deelfontein. 



1.7.9.35,36. j 



This is a form which combines some characters from each 

 of its neighbours, griquce on the north and pumilio on the 

 east. From the former it differs by its smaller hind foot and 

 bullee and from the latter by its smaller hind foot and tooth- 

 row. It is most variable in its coloration, no two specimens 

 being exactly alike, and, judging from collector's measure- 

 ments, the tail is slightly longer than the head and body. 



The normal dimensions may be taken as : — 



Head and body 105 mm. ; tail 108; hind foot 22. 



Skull: basilar length 21*5; length of tooth-row 4-6; 

 bullifi 6. 



The measured dimensions of some selected specimens are 

 as follows : — 



Basilar 

 Hind length of Length of 

 foot. skull, tooth-row. Bullae. 

 2. 9.]. 69. $. Old.... 22 ? 4-6 6 



2.9.1.70. ?. Y. adult. 22 20-5 4-6 6 



2.9.1.71. $. Adult.. 22 21 4-6 (j 

 (Type) 3. 1. 4. 53. d . V.old.. 22 21-5 4-6 G 



1.7,9.35. ?. Old.... 22 21-5 4-6 G 



