526 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



This is very nearly 25 miles from Grand Eapids in a straight line in 

 a direction a little north of northwest. The depth at which the skull 

 was found was about 2 or 3 feet only. Mr. Sargent informed the 

 writer that the skull lay beneath the pelvis of a mastodon, the nearly 

 complete skeleton of which is mounted in the Kent Scientific Mu- 

 seum. 



The following measurements were secured from the skull. Inas- 

 much as it is much damaged in its axial portions many desirable 

 measurements, especially the basilar length, could not be obtained. 

 A figure is shown (pi. 31, fig. 2) which gives a view of the skull 

 from the left side. Mr. Gid ] ey published a figure from the same 

 photograph. 



Measurements of skull of Bootherium sargenti in millimeters. 



Distance from the rear of one orbit to that of the other 190 



Width of skull between the orbits and the horn-cores, on a level with the 



lower surface of the latter 128 



Width^of space between the horn-cores at their rear 147 



Width of space between the horn-cores, on the face, least 62 



Fore-and-aft diameter of the orbit 65± 



Length of a horn-core along the hinder curve 352 



Circumference of the base of a horn-core 242 



Fore-and-aft diameter of a horn-core 80 



Diameter of horn-core at right angles to preceding 68 



Distance between tips of horn-cores, direct 505 



Width of brain cavity 88 



The distance from the occipital crest to the notch for the rear end 

 of the nasals was close to 210 mm. ; the crest itself is missing. In 

 Bootherium bombifrons this distance is 240 mm. 



The horn-cores (pi. 31, fig. 2) are directed strongly outward and 

 forward and somewhat downward. The distal extremity of each 

 reaches a point 55 mm. in front of the rear of the nasals and 95 mm. 

 below the upper surface of these bones. At the base the horn-core is 

 subcircular in section; but the upper face is considerably flattened. 

 However, at a short distance from the base the section becomes 

 nearly circular. The surfaces of the cores are strongly grooved. A 

 fragment of each of the nasals about 70 mm. long is present and to 

 each is attached a fragment of the maxilla. 



The profile of this skull is not straight. It is convex in the region 

 of the horn-cores and concave between the orbits. 



Dr. J. A. Allen x has expressed the opinion that this skull represents 

 merely the female of Symbos eavifrons and that it shares no essential 

 features with Bootherium bombifrons. He says that the horn-cores 

 are attached to the skull as in the female of Ovibos, with about the 

 same relative area of exostosis extending from the base over the 



1 Mem. Amer. Mus. Nat. Hist., vol. 1, pp. 214, 215. 



