(189) 



NEW OR LITTLE-KXOWV RATS 



17 



2. d" imm.; in ale. Mombasa, British East Africa. Collected by Mr. D. J. 



Wilson. Presented by Mr. G. Waller. British Museum no. 91. 9. 7. 2. 



3. d" ad.; in ale. Fort Johnston, Nyasa; Dec. 1895. Presented by Sir Harry 



H. Johnston. Brit. Mus. no. 96. 10. 28. 12. 



4. Q ad.; in ale. Shire, Lower Zambesi. Collected by Livingstone. Presented 



by Earl Russell. Brit. Mus. no. 63. 11. 12. 13. 

 5-7. Q ad.; in ale. Shupanga, Lower Zambesi. Presented by Dr. J. Kirk. 

 Brit. Mus. nos. 64. 12. 10. 10-12. 



The types of Rh. lobatus, in the Berlin Museum, are from 

 Sena and Tette, Lower Zambesi; nos. 3-7 of the specimens enu- 

 merated above are from the same region. No. 2 extends the range 

 of the species to British East Africa, and no. 1, from the Genoa 

 Museum, as far as Gallaland. I am unable to see any appreciable 

 difference between all these examples. 



Affinities. — Rh. alcyone, landeri lobatus, and dobsoni 

 ( 2 ) are Ethiopian descendants of the Oriental Rh. minor type. 

 Their presence in Africa is an evidence, among many others, of 

 a formerly much more intimate land-connection between South 

 Asia and Equatorial Africa. They have, in all essential respects, 

 preserved the cranial and dental features of the Oriental species; 

 also the very characteristic projecting, triangular, pointed connecting- 

 process. But they are on a considerably higher level of develop- 

 ment in the wing-structure (see above, Rh. alcyone) and in the 

 pandurate shape of the sella. 



Rh. landeri and lobatus are very closely related. Rh. landeri 

 has a shorter tibia and tail; the skull is rather more slender than, 

 but in other respects quite similar to, that of lobatus; the dentition 

 is the same. It is not unlikely that, when a completer material 

 is to hand, we shall have to regard Rh. landeri and lobatus 

 as western and eastern representatives of one species. 



As to Rh. dobsoni, from Kordofan, I have some doubt that 

 it is distinguishable from Rh. lobatus; but having seen only two 

 examples of the former (the type and a topotype), both of them 

 in not quite satisfactory state of preservation , I prefer for the 



(') The following specimens of Rh. landeri have been examined: — Q ad. (in ale); 

 Fernando Po; Zoological Society's Collection; Brit. Mus. no. 55. 12. 26. 250 (type of 

 species). — Q vix ad. (in ale); Elloby District, Gaboon; Brit. Mus no. 74. 10. 6. 6. — 

 Skulls of both examples. 



( 2 ) Oldfield Thomas, Ann. & Mag. Nat. Hist. (?) XIV. p. 156 (Aug. 1, 1004). — 

 Specimens examined: — c? ad., Q ad. (in ale); Kordofan; Brit. Mus. nos. 47. 5. 7.45 

 and 47. 5. 7. 40 (type of species). Skull of the type. 



