Dr. N. Severtzoff on the Mammals of Turkestan. 221 



Wagner (Schreber's 'Saugethiere,' Fortsetz. v. A. Wagner) 

 assigns also the skulls and liorns observed by Barns in 

 Bucliara : lie says, " The horns are more slender, longer, and 

 more compressed than those of 0. argali, and are curved in a 

 rather larger circle ; but these characters, as mentioned before, 

 are also found in 0. Heinsii and 0. nigrimontana!''' The 

 horns of 0. Polii are strongly compressed ; on the orbital 

 surface there is a furrow between the two convex portions of 

 the surface ; there is also a similar depression on the frontal 

 surface ninning parallel with the fronto-orbital edge ; in 

 young specimens this is sharply marked, but with the advance 

 of age this furrow gets deeper and wider. The nuchal sur- 

 face of the horn is flat ; consequently the fronto-nuchal edge is 

 sharp and forms a triangle with a rounded point. In the 

 section at the horn's base the width of the orbital surface is 

 twice the line drawn from the middle of it across the horn to the 

 fronto-nuchal edge ; the width of the frontal surface is almost 

 equal to that of the nuchal surface. 



The angle formed by the basal chord with the axis of the 

 skull shows 41°, or is more than three times the angle 

 formed by it with the median chord, namely 12°, but is 

 much less than that of the terminal chord, which shows 60° ; 

 both rising chords are long. 



The spiral of the horn fits on an inserted cone the point of 

 which is turned towards the skull and the base to the outside ; 

 the axis of this cone points towards the front, and still more 

 so when the animal advances in age. The inner surfaces of 

 the horns join almost at a right angle, with a rather blunt 

 point in young and a very sharp one in old specimens, namely 

 from 3° to 4°. The ridges of the horns are meandering and 

 irregular, a great portion of them branching off in two or more 

 branches. 



The occipital ridge is pointed and forms in its section a 

 sharp angle with a slightly rounded point ; the forehead, com- 

 mencing from the bridge of the nose, rises very steeply ; out of 

 the three processes of the frontal, the anterior one (just above 

 the eye) is very small and sometimes disappears altogether, so 

 so that only the two others remain. The length of the forehead, 

 from the base of the horns as far as the upper extremities of the 

 nasals, is scarcely more than two thirds of its width between 

 the orbits. This proportion differs very little according to the 

 animal's age, as the length and width of the forehead increase 

 equally quickly ; the forehead of 0. Karelini^ on the contrary, 

 grows more in length than it does in width, and consequently 

 the proportions of these measurements alter very much in the 

 different ages of the animal. 



