568 Mr. P. S. Kershaw on new 



tunily of putting on record some conclusions I have 

 reached : — 



(1) Taterona can be divided into forms with tufted and 

 forms with untufted tails. The former are either heavily 

 tufted, as in the Asiatic genus Tatera, e. g., Taterona nigri- 

 cauda^ or slightly tufted, e. g., T. vicina. 



(2) The tufted forms are all, with one exception {T, guinea^., 

 from Gunnal, in Portuguese Guinea), confined to North-east 

 Africa. These are all to the north of a line drawn from 

 Mombasa to Morogoro, and thence to Muansa on the south 

 shore of Lake Victoria Nyanza, and of a line drawn from the 

 nortli-east corner of that lake to Mt. Elgon, and thence to 

 the Nile at the northern extremity of Lake Albert. The 

 untufted forms are found all over Africa except the norlh- 

 wi sf, and share North-east Africa with the tufted forms. 



(3) In the untufted forms the posterior palatal foramina are 

 shoit and in the tufted long. Tliis is what we should expict 

 to find, since, in the heavily tufted Tatera of Asia, the 

 ])osterior palatal foramiiui are very long. In Tatera perxica 

 they are almost as long relatively as .in Taterillus. Where 

 tlie posterior foramina are long, the space between the anterior 

 and posterior foramina is short, and vice versa. In the 

 untufted forms, of which there are thirty-one t3''pe-speciniens 

 in the British Museum, this space measures anything frc)m 

 3 to 5 mm., except in nigrita from Uganda, where it measures 

 2 G mm. In the tufted forms, of whicii the Museum possesses 

 six type-skulls, it measures 2*5 to 3 mm., except in the 

 remote g^ii/iece (3"5 mm.) and in swaythlingi, the southernmost 

 form (3'6 n)m.). 



I have treated as " tufted ^^ in this paper T. rohustn, ma- 

 cropus, 7iigricauda, vicina, moinhasce, pldllipsi, nmhrom, 

 s/ioana, pother ij guinea;, and siouythlingi, and as ''untufted" 

 all the other forms, ignoring; the sul)genus Gerhilliscus. 



Vide also on this subject Hinton and Kershaw, Ann. & Mag. 

 Nat. Hist. (9) vi. p. ^^ (July 1920). 



Rattiis p)&r nanus, sp. n. 



Among a collection of skins sent by tlie Nairobi Museum 

 in the Kenya Colony to the British Museum recently for 

 identification, there are two of a Eattus, which requires 

 description as a new form : — 



Type. Young adult male. B.M. no. 21. 9. 6. 15. Originnl 

 number 34. Collected by Mr. R. B. Woosnam on 3rd Nov- 

 ember, 1912, and presented to the British Museum by the 

 Nairobi Museum. 



