134 



TJiE MAMMALS OF ETHIOPIAN AFRICA 



kangaroos, going 



faster 



uphill than down, but in neither case attaining any 

 very great speed. 



Rock-Rat The tyP icall y Sou tn American degu family (Octodontidce) has a 



few African representatives, among which is the rock-rat (Petromys 

 typicus) of Namaqualand. Brownish grey in colour, this rodent measures about 

 6 inches to the root of the tapering scaly tail, of which the length is only half an 

 inch less than that of the head and body. The feet are five-toed, although in the 

 front pair the first toe is reduced to a mere tubercle ; the soles of the front toes 

 having five and those of the hind pair six pads. Rock-rats are restricted to stony 

 districts, where they may be seen abroad at all times of the day, in search of the 

 flowers which form their chief food. At night they sleep safely curled up in rocky 

 clefts or beneath protecting boulders. 



Cane-Rats. 



To the same family belongs the much larger rodent known as the 

 cane-rat (Thryonomys, or Aulacodus, s winder ianus), which is the 

 typical representative of an exclusively African genus, the members of which are 

 found from the Nile tributaries to the Cape, and on the west coast as far north 

 as Sierra Leone. Often known as ground-rats, these rodents have bristly coats 

 speckled yellow and brown, with a white chin and upper lip, and short broad 

 ears. In length the tail measures 7 inches, and the head and body 19 inches. 

 The lower front teeth are smooth, but the upper pair are marked with three 

 deep vertical grooves, and are so powerful that the marks of their grooves 

 have been detected on ivory gnawed by these rodents. In South Africa cane- 

 rats appear to make for their retreat a sort of nest constructed in the ground 

 amid a tangle of grass and reeds from which they can with difficulty be 

 driven. They feed on roots, tender shoots, and the sugar-cane from which 

 they take their name. 



