NO. 2086. 



SOME MAMMALS OF THE PLEISTOCENE— HAY. 



553 



From careful measurements of these and comparison of the measure- 

 ments some important results may be secured. 



Therefore, from the tables presented by Nehring, Tscherski, and 

 Salensky and from measurements made on specimens in the United 

 States National Museum and in the American Museum of Natural 

 History, the writer has prepared a number of tables, which follow. 

 The measurements used are: The basilar length; the vertex length 

 (from the middle of the occipital crest to the incisive border) ; 

 frontal width (greatest width at the rear of the orbits) .; the cranial 

 length (distance from the middle of the occipital crest to the middle 

 of the line joining the rear of the orbits) ; the facial length (the 

 distance from the incisive border to the middle of the orbital line 

 just described) ; the distance from the lower border of the foramen 

 magnum to the notch in the rear of the vomer ; and the distance from 

 the vomerine notch to the rear of the hard palate. The cranial 

 length is obtained by first measuring from the midline of the occip- 

 ital crest to the rear of the orbit. This distance is made the hy- 

 pothenuse of a right-angled triangle whose base is half of the frontal 

 width. The other side, representing the cranial length, is then deter- 

 mined mechanically and, if necessary, confirmed arithmetically. 

 The result is believed to be more exact than that obtained by direct 

 measurement on the surface of the skull. 



The following table has been partly compiled and partly computed 

 from one specimen measured by Tscherski, from the measurements 

 of five horses, as given by Salensky in his work on Equus przevalskii, 

 and from three specimens in the American Museum of Natural His- 

 tory. Only adult specimens have been considered. 



Measurements of skulls of Equus przevalskii in millimeters, with indices. 



Specimen. 



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. 



5218, Salensky 



212, Salensky 



5214, Salensky 



5216, Salensky 



5213, Salensky 



512, Tscherski 



32686, Am. Mus 



136, Am. Mus 



71. Am. Mus 



481 

 472 

 484 

 495 

 485 

 440 

 493 

 480 

 457 



543 



528 

 538 

 547 

 542 

 488 

 550 

 532 

 507 



201 

 202 

 20S 

 209 

 212 

 188 

 212 

 208 

 200 



41.2 



42.8 

 42.9 

 42.2 

 43.7 

 42.6 

 43.0 

 43.4 

 43.7 



175 

 170 

 172 

 169 

 173 

 150 

 176 

 167 

 155 



36.4 

 36.0 

 35.5 

 34.1 

 35.6 

 34.1 

 35.7 

 34.8 

 33.9 



376 



364 

 366 

 377 

 373 

 335 

 380 

 368 

 351 



78.2 

 77.1 

 75.6 

 76.2 

 76.9 

 76.1 

 77.1 

 76.6 

 76.8 



118 

 125 

 117 

 123 

 119 

 112 

 119 

 125 

 121 



105 

 110 

 110 

 109 

 105 

 100 

 103 

 96 

 92 



Averages 



476 



531 



204 



42.9 



171 



35.1 



363 



76.7 



120 



103 



As regards the basilar length, it will be observed that the difference 

 between that of the largest skull and the smallest one is only 55 mm., 

 and that the difference between the greatest frontal width and the 

 least is only 24.5 mm. As to the cephalic index, which shows the rela- 



