the "adult value," as in Old. Horn. 13 (which is dentally of about the same 

 age). If 620 c.c. represents 98 per cent of the "adult value," the total that 

 should be recorded as the "adult value" is 633 c.c. (or, following Hollo- 

 way, 638 c.c). This value of 633 c.c. exceeds by 93 c.c. the largest estimate 

 for an adult australopithecine of the present sample, namely 540 c.c. for 

 the Taung "adult value." It exceeds my estimate of the mean for A. 

 africanus (494 c.c.) by 139 c.c, or 3.35 S.D.s, while it surpasses Hollo- 

 way's (1970) mean of 442 c.c. by 191 c.c, or 8.85 S.D.s. 



Other East African hominids with habiline 



cranial capacities 



Olduvai hominid 24, which was found in 1968 at the site DK in Bed I, 

 possessed a severely crushed cranium and smallish teeth. It has been skill- 

 fully reconstructed by Mr. R. J. Clarke, and he has made a plaster and a 

 plastic cast of the specimen. Mr. Clarke has kindly permitted me to quote 

 his very tentative determination of the volume of the endocast: it is of the 

 order of 600 c.c but, because of crushing and distortion, may have been 

 "well above that." Here, then, we have a fourth member of the "over 600" 

 club from Olduvai. 



Crania that may have capacities in this range— that is, about half as big 

 again as A. africanus— ha\e come to light, as well, in central and northern 

 Kenya. At the time of writing, however, details are not available. 



Summary on the cranial capacities of Olduvai 

 Hominids 7, 13, and 16 



All 3 of the Olduvai specimens that have been officially allocated or 

 provisionally referred to H. habilis have capacities in the 600s, and all 3 ex- 

 ceed the mean for A. africanus from South Africa by more than 3 standard 

 deviations. Details are as follows: 



Type specimen of H. habilis (Old. Horn. 7) 684 c.c. 



Paratype of H. habilis (Old. Horn. 13) 652 c.c. 



Provisionally referred to H. habilis (Old. Horn. 16) 633 c.c. 



The mean for the type and paratype of H. habilis comes to 668 c.c, 

 which is 174 c.c, or 4.19 S.D.s, greater than the mean for A. africanus 

 (494 c.c). If we include the provisionally referred specimen Old. Horn. 

 16, the range for the 3 specimens is 633 to 684 c.c, and the mean is 656 c.c. 



^ 80 



