158 



BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 



Although skins of this race are only very slightly paler than skins of 

 true surdaster from Naivasha, the skulls are readily distinguished 

 by constant characters. A profile view of the skull presents an evenly 

 rounded outline from the mastoids to the nasals; whereas in the 

 Naivasha form the braincase is much higher and the depression in 

 the frontals much lower so that the upper outline in profile presents a 

 very uneven line, much raised posteriorly and with a decided depres- 

 sion over the lachrymal region. The rostral and orbital regions of the 

 skull are much deeper in the Athi Plains form than in typical sur- 

 daster from Naivasha; and the suture between the frontals and 

 parietals is almost straight across the skull with only a slight ante- 

 riorly rounded convexity, while in the large series of nearly 50 skulls 

 of typical surdaster this suture presents a distinct and usually sharply 

 pointed salient into the frontals. 



Measurements oj East AJrican specimens oj Pedetes. 



Locality. 



P. s. surdaster, 



Naivasha Station. . . 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



P. s. curraz. 



KabalolotHill 



P. s. larvalis. 



Ulukenia Hills 



Do 



Do 



No. 



Sex. 



162178 

 162187 

 162188 

 162193 

 162198 

 162199 

 162200 

 162202 

 162203 

 162207 

 162167 

 162169 

 162170 

 162175 

 162182 

 162190 

 162192 

 162194 

 162204 



3 181762 



163303 



s 163304 



163915 



Male 



...do.... 

 ...do... 

 ...do..., 

 ...do..., 

 ...do..., 

 ...do... 

 ...do... 

 ...do... 

 ...do.... 

 Female . 

 ...do.... 

 ...do... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



Male... 



Female 

 ..do... 

 ..do... 



p a 



72.7 

 73.5 

 74.9 

 74.5 

 72.4 

 72.4 

 72.1 

 74.3 

 73.9 

 74.9 

 72.3 

 73.3 

 73.1 

 70.4 

 73.5 

 71.7 

 71.9 

 73.6 

 73.0 



75.3 



72.4 

 78.2 

 76.2 



53.7 

 53.7 

 52.0 

 54.5 

 55.1 

 56.5 

 54.0 

 54.6 

 54.8 

 56.5 

 52.8 

 55.0 

 55.9 

 54.0 

 56.8 

 55.0 

 52.8 

 52.9 

 54.2 



55.7 



53.8 

 55.2 

 52.3 



15.7 

 14.6 

 14.9 

 14.9 

 15.2 

 15.6 

 15.2 

 14.4 

 15.9 

 14.9 

 14.9 

 15.3 

 15.8 

 15.6 

 15.8 

 15.1 

 15.2 

 15.6 

 15.2 



15.9 



15.1 

 16.3 

 16.1 



1 Taken in this ease to the most anterior point of premaxillary bone. 



2 From median anterior alveolar line to highest point on crown directly above lachrymal bone. 



3 Type. 



