230 Annals of the South African Muse inn. 



Dimensions (of the type, a male in the flesh). Head and hody 

 5-75 ; hind foot '96 ; skull length 1-22, breadth T06. 



Distribution. The type together with several other examples, 

 were all obtained by Mr. Selous, at Essex Vale, a farm near Bula- 

 wayo, and are now in the British Museum. 



FAMILY PEDETIDAE. 



GEN. PEDETES. 



Pedetes, ILLIGER, Prodr. Syst. Mamm., p. 81 (1811). Type P. 

 caffer. 



Helamys, F. CUVIER, Diet. Sci. Nat., xx., p. 344 (1817). Type P. 

 caffer. 



Form kangaroo-like, with short fore limbs, and well-developed 

 hind limbs, the metatarsus being especially elongated and the 

 metatarsal bones separate from one another ; there are four toes 

 armed with hoof-like nails. 



Skull short and broad with very wide and expanded nasals, ant- 

 orbital opening very large and oval ; malar bone ascending from 

 the zygomatic arch in a horizontal plate to meet the lachrymal 

 bone ; cervical vertebrae free. 



Dentition. i. 1/1 ; c. 0/0; p.m. 1/1 ; m. 3/3 = 20 ; molars rootless, 

 with a single deep enamel fold externally in the upper jaw, internally 

 in the lower jaw. 



This genus, the only one of the family, and containing the single 

 species below described, is a rather anomalous one, and has no near 

 allies, so that its position among the other rodent families has varied 

 considerably. Mr. Alston, in his classical paper on the arrangement 

 of Eodents (Proc. Zool. Soc., 1876, p. 61), placed it in a special 

 sub-family of Dipodidac, or Jerboa rats, among the Myomorplia ; 

 several authors have recognised the fact that the resemblances 

 between the Jerboas and Pedetes are artificial and adaptive rather 

 than natural, and Dr. Winge, of Copenhagen, in a general revision 

 of the Eodents," placed the Pecletidac between the Sciuridae and the 

 Anomoluridae ; Mr. 0. Thomas, t however, in his recently published 

 list has transferred the family to the Hystricomorplm, and placed 

 them at the commencement of the series ; on the whole, most of 



* Jordfnndene og nulevende Gnavene fra Lagoa Santa E. Mus Lundii, iii. (1887). 

 t Proc. Zool. Soc. (1896), p. 1012. 



