Annals of the South African Museum. 



examples from the Port Elizabeth, Albany, Graaf Eeinet, and Middel- 

 burg Divisions of the Colony, it is also found throughout the Orange 

 Free State, Griqualand West, Bechuanaland, the Transvaal, 

 Bhodesia, and German South-West Africa. 



FAMILY OCTODONTIDAE. 



GEN. PETEOMYS. 



Pctromys, A. SMITH, S. Afr. Quart. Journ., i., No. 5, p. 11 (1831). 

 Type P. typicus. 



Compact, rounded animals with moderate rounded ears, with tails 

 only a little shorter than the body covered with stiff hairs, which 

 become longer towards the tip ; five toes to both fore and hind 

 limbs, the pollex, however, being short and rudimentary. 



Skull very broad posteriorly, with very large antorbital openings, 

 at the base of which is a groove for the passage of the nerve. 



Dentition. i. 1/1; c. 0/0; p.m. 1/1; m. 3/3 = 20; upper incisors 

 smooth, small, and compressed ; molars rooted somewhat quadrate 

 with a single fold internal in the upper and external in the lower 

 jaw, and with indications of smaller opposite folds external in the 

 upper, internal in the lower jaw. 



Only one species of this genus, that below described, is known. 



PETKOMYS TYPICUS, THE BOCK BAT, OB NOKI. 



Petromys typicus, A. SMITH, S. Afr. Quart. Journ., i., No. 5, p. 11 

 (1831) ; ID., ibid., ii., p. 146 (1834) ; ID., Illustr. Zool. S. Afr. Mam., 

 plates xx., xxi. (skull and anat.), (1849); WATEEHOUSE, Nat. Hist. 

 Mam., ii., p. 308, pi. xvi., fig. 8, pi. xvii., fig. 1 (1848). 



Description. General shape rat-like ; colour dull brownish grey, 

 pencilled tawny and black, hinder part of the back and posterior 

 extremities dull chestnut, all the hairs bluish grey at the base ; below 

 dull white tinged with tawny ; apex of the muzzle and orbit bright 

 chestnut, whiskers long, rigid, and black, snout projecting and 

 truncated ; ears rather small, wider than high, blackish, only 

 moderately clothed with hair ; fore limbs with four clawed toes, 

 the first being represented by mere tubercle, palms with five rather 

 swollen pads ; claws back ; hind limbs somewhat thickened, hairy 

 above, naked below, with six pads, the three at the base of the toes 

 large and oval, the two next small and rounded, the proximal one 



