---------------------------------------------------+---------+---------- | P. pal. | P. major. +---------+---------- LOWER JAW. | M. | M. Incisor series | ···· | ·073 Median incisor fang, length | ···· | ·034 Median incisor crown, length | ···· | ·012 Diameter of median incisor crown, transverse | ···· | ·009 Diameter of lateral incisor crown, transverse | ···· | ·011 Diameter of lateral incisor crown, antero-posterior| ···· | ·012 Length of fang of canine | ·055 | ·052 Extreme breadth of fang of canine | ·023 | ·024 Crown of canine, length | ···· | ·034 Crown of canine, fore-and-aft diameter at base | ·019 | ·021 Diameter of first premolar, antero-posterior | ·015 | ·010 Diameter of first premolar, transverse | ·009 | ·007 Diastema between first and second premolars | ···· | ·014 Length of entire molar series | ·164 | ·186 Length of molar series, omitting first premolar | ·132 | ·163 Diameter of last molar, antero-posterior | ·017 | ·050 Diameter of last molar, transverse | ···· | ·027 Depth of jaw below last molar | ·068 | ·075 ---------------------------------------------------+---------+---------- Among other specimens obtained at the divide between Henry's Fork and Cottonwood Creek, was a nearly complete but somewhat shattered skeleton of a _Palæosyops major_, found contiguous to the head of the same, parts of which are just described. Portions of these are figured on a one fourth scale in Plate II. The description is from a nearly perfect atlas and axis, several cervical, dorsal, and lumbar vertebræ, more or less complete, and a portion of the sacrum and pelvis, in addition to several bones of the limbs. The _atlas_ has a broad inferior arch, contracted antero-posteriorly, and deeply notched for the prominent odontoid of the axis. The heavy superior arch, inclosing a large and depressed neural canal, is capped by a low tuberosity. It slopes into a flat, and very broad transverse process, which thickens backwards, and is perforated by the vertebraterial canal. Forwards the transverse process is notched for the exit of the first spinal nerve. The anterior or condylar faces are continuous, deeply concave from above downwards; and slightly so from side to side; while the posterior faces are oval, nearly flat, and directed backwards and inwards.