no. 2086. SOME MAMMALS OF THE PLEISTOCENE— HAY. 



555 



Measurements of skulls of Equus quagga granti m millimeters, with indices. 



Specimens in U. S. 

 National Museum. 



Basilar 

 length. 



Vertex 

 length. 



Frontal 

 width. 



Ce- 

 phalic 

 index. 



Cranial 

 length. 



Cranio- 

 cephalic 

 index. 



Facial 

 length. 



Facio- 

 cephalic 

 index. 



For. 



mag. to 

 vomer. 



Vomer 



to 

 palate. 



161930 cf 



440 



437 

 443 



475 

 447 

 440 

 437 

 427 



486 

 498 

 510 

 538 

 513 

 508 

 498 

 500 



185 

 190 

 181 

 194 

 183 

 188 

 185 

 182 



42.0 

 43.5 

 41.4 

 40.8 

 40.9 

 42.7 

 42.3 

 42.6 



157 

 171 

 180 

 176 

 173 

 175 

 158 

 167 



35.7 

 39.1 

 41.5 

 37.1 

 38.7 

 39.7 

 36.1 

 36.5 



335 

 328 

 335 

 370 

 345 

 344 

 335 

 333 



76.1 

 75.1 

 77.3 

 77.9 



77.2 

 78.2 

 76.6 

 78.0 



108 

 107 

 113 

 108 

 108 

 105 

 107 

 110 



100 



162957 ? 



102 



161929 d 



110 



162950 cf 



120 



181947 <? 



113 



162953 9 



104 



162239 ? 



108 



162960 c? 



100 









443 



506 



186 



42.0 



170 



38.5 



341 



77.1 



108 



107 



Among the eight skulls of this subspecies there is found to be a 

 difference of 48 mm. between the longest and the shortest basilar 

 length, and there is a difference of only 13 mm. between the greatest 

 and the least frontal width. The cephalic index passes neither 

 above nor below the mean more than about 3.5 per cent, and the 

 difference between the highest and the lowest amounts to less than 

 6.5 per cent of the mean; the facio-cephalic index varies still less. 

 The vomerine notch is near the median point between the foramen 

 magnum and the hard palate. 



Measurements of skulls of Equus quagga craivshayi in millimeters, tvith indices. 



Specimens in U. S. 

 National Museum. 



Basilar 

 length. 



Vertex 

 length. 



Frontal 

 width. 



Ce- 

 phalic 

 index. 



Cranial 

 length. 



Cranio- 

 cephalic 

 index. 



Facial 

 length. 



Facio- 

 cephalic 

 index. 



For. 

 mag. to 

 vomer. 



Vomer 



to 

 palate. 



61744 c? 



462 

 432 

 471 



525 

 505 

 541 



177 

 181 

 195 



38.3 

 41.9 

 41.4 



165 

 168 

 191 



35.7 

 38.9 

 40.5 



365 

 341 

 364 



79.0 

 78.9 

 77.3 



108 

 108 

 126 



106 



38212 9 



108 



38211 cf 



101 







Averages 



441 



524 



184 



40.5 



175 



38.4 



357 



78.4 



114 



105 



Of the subspecies Equus quagga crawshayi there are in the United 

 States National Museum only three skulls. In size, as represented 

 by the basilar length, they are all within the limits of the skulls of 

 Grant's zebra. The cephalic index of one specimen falls to 38.3, as 

 low as in some skulls of Grevy's zebra, but in the others the index 

 is nearly up to the average found in Grant's zebra. The index 38.3 

 falls below the average of that of Grant's zebra less than 9 per cent. 

 The small number of specimens measured makes it impossible to 

 determine whether or not this is an abnormal individual or whether 

 there is great variability in this form. And attention may be here 

 called to the fact that in these lists it is just in those cases where 

 there are few individuals measured that there are found the greatest 

 differences. This fact is illustrated likewise in the two following 

 tables. 



