156 LIST OF DIUBNAL BIRDS OF PREY. 



APPENDIX L. 



Oil Tinnun cuius arthuri. 



In the list of a collection of birds from Mombasa, which I 

 contributed to the 'Ibis' for 1881 [vide ^. 124)^ a Kestrel 

 Avas included wbich was not sexed by the collector, but 

 which, on a too cursory examination, I took to be a " female 

 in worn plumage *' of T. alaudarius. I subsequently alluded 

 to this specimen, in a footnote to p. 457 of the same volume, 

 as being "remarkable for having narrow brown transverse 

 bars on the sides of the breast;" and at p. 462 I gave its 

 principal measurements, showing that it has a shorter wing 

 than twenty males of T. alaudarius from Europe, Africa, and 

 Asia with which I compared it. 



I have subsequently given this Kestrel a good deal of con- 

 sideration, and have come to the conclusion that I was 

 wrong in referring it to T. alaudarius, and that I should be 

 equally so were I to refer it to any other species hitherto 

 described ; it comes nearest in its markings to T. rupicoloides, 

 but its much smaller size separates it from that species as 

 decidedly as the peculiarity of its markings, especially on the 

 flanks, distinguishes it from T. alaudarius. 



I find, on examining six Transvaal males of T. rupicoloides, 

 that the measurement of the wing varies from 10"70 to 

 11*55 inches, that of the tarsus from 1*85 to 2, and of the 

 middle toe s.u. from 1"20 to 1*35; in the Mombasa Kestrel 

 one wiug measures 9 30 and the other 9*40, the tarsus \'70, 

 and the middle toe s. u. 1*15; as regards markings it 

 resembles, in those of the head, scapulars, and wing-coverts. 



