1884.] MR. W. T. BLANFORD ON HEADS OF OVIS POLL 327 



given in the paper I have quoted, the length of a horn round the 

 curve varies from 42| inches to 48J, the mean being 45, and the 

 distance from tip to tip of horns in a straight line 31 to 36, mean 

 33 ; whilst in six adult specimens of O. poli the length o/ horn is from 

 49 to 63, mean 55-25, and the distance between the tips 43| to 55, 

 mean 48'25 ; or the mean ratio in 0. karelini is 100: 73, and in 0. poli 

 100 : 87 \ 



The following are the measurements of the eleven specimens now 

 exhibited. Where there is any difference in the length of the two 

 horns, that of the longer horn is given, it being assumed that the 

 deficiency in the other is due to wear. The horns are measured 

 from the base in front over the outside curve of the frontal surface 

 to the tip ; the distance from tip to tip is of course measured in a 

 straight line. 



In the last specimen one horn is slightly imperfect at the end, 

 and an allowauce is made for the deficiency in estimating the length 

 from tip to tip. 



Figs. 1 and 3 (p. 328) represent the extreme types. Fig. 2 is taken 

 from an intermediate head with singularly stout horns, each of 

 them measuring 17 inches in circumference at the base, whilst the 

 much longer horns of figs. 1 and 3 have the circumference respectively 

 of only 15^ and 16 inches. 



It is unnecessary to point out that these heads completely bridge 

 the interval between the two forms O. poli and O. karelini so far as 

 the curve of the horns is concerned. 



The other distinctive characters to which importance was attached 

 by Severtzoff are the following, so far as I can make out the 

 distinctions from the translation of his work. 



1. In O. poli the horns are pressed in from the sides, especially the 

 orbital surface 2 . In O. karelini the orbital surface is flat, the frontal 



1 The extremes are, in O. karelini 100 : 67 and 100 : 79, in O. poli 100: 79 and 

 100 : 101 ; but none of the specimens of O. karelini had horns exceeding 48£ 

 inches in length, and it appears to be evident that, as a rule, the greatest pro- 

 portional divergence is shown by younger animals. 



2 For meaning of these terms, see P. Z. S. 1875, p. 511. 



