402 



0. alpestris (L.) (Syst. Nat. i. p. 289), which inhabits the entire Northern Palsearctic and Nearctic Regions. 

 0. brandti, mihi. A desert form, resident in the Kirghis steppes. 

 O. peregrina, Sclater (P. Z. S. 1855, p. 110). A resident in New Granada. 

 0. bilopha, Riipp. (PI. Col. 244. fig. 1) . A desert form inhabiting North Africa. 



O. penicillata, Gould (P. Z. S. 1837, p. 126). Inhabits South-eastern Europe, and is found eastward to 

 Thibet. 



The followin 



g- 



Cable will show the variation in size 



of the different 



, species : — 







Culmen. 



Wing. 



Tail. 



Tarsus. 





inch. 



inches. 



inches. 



inch. 



0. alpestris . . . England. 



0-50-0-52 



3-85-4-1 



2-60-2-75 



0-85 



>> 







Norway. 



0-55-0-57 



4-0 -4-2 



2-80-2-85 



0-86-0-88 



!> 







North Russia. 



0-52 



4-3 



2-75 



0-8 



)' 







Volga. 



0-5 



4-2 



2-83 



0-84 



)1 







Siberia. 



0-52 



4-4 



2-95 



0-9 



>> 







Peking. 



0-5 



4-1 



2-75 



0-87 



>> 







Tientsin. 



0-62 



4-05 



2-9 



0-85 



» 







W. of Rocky Mountains. 



0-57 



4-2 



30 



0-85 



» 







Vancouver. 



0-50-0-57 



3-98-4-0 



2-50-2-75 



0-85-0-88 



;> 







New Brunswick. 



0-50-0-55 



4-20-4-3 



2-80-2-9 



0-85-0-88 



>> 







Texas. 



0-50-0-6 



3-90-4-15 



2-60-3-0 



0-85-0-9 



33 







Mexico. 



0-50-055 



3-90-4-0 



2-8 



0-80-0-85 



0. brandti . 







Kirghis Steppes. 



0-52 



4-4 



3-3 



0-82 



0. peregrina 







Bogota. 



0-45-0-52 



3-35-3-7 



2-20-2-4 



0-8 



0. bilopha . 







Algeria. 



0-55-06 



3-75-3-8 



2-80-2-85 



0-80-0-82 



0. penicillata 







Syria. 



0-65 



4-5 



325 



09 



>> 







S.E. Persia. 



0-65-0-72 



4-30-4-6 



315-3-3 



085-0-9 



>> 







Caucasus. 



0-65 



4-55 



33 



0-9 



» 







Kulu. 



0-75-0-8 



4-62-5-05 



310-3-6 



09 



,) 







Thibet. 



0-8 



51 



3-6 



0-9 



I do not possess the nest or eggs of this species, and can therefore add nothing to the above 

 description of these by Major Loche. 



The specimen figured is the adult male from Algeria, above described. 



In the preparation of the above article I have examined the following specimens : — 



E Mus. H. E. Dresser. 



a, b, 6 . Algeria (Fairmaire) . 



E Mus. H. B. Tristram, 

 a, 6 . El Baadj, Sahara, January 17th, 1857. b, ?. Laghouat, Sahara, November 26th, 1856 (H. B. T.). 



