THE IBIS. 



THIRD SERIES. 



SUPPLEMENT, 1873. 



XL VII. — Index to the Ornithological Literature of 1872. By 

 P. L. Sclater, M.A., Ph.D., F.R.S., and O. Finsch, Ph.D. 



Aiken, C. E. 



[See Holden, Jr., C. R.] 



Allen, J. A. 



1. Remarks concerning the Geographical Variation in Mam- 

 mals and Birds. Proc. Bost. Soc. N. H. xv. pp. 156-159. 



These remarks relate principally to the general laws of de- 

 crease in the size of individuals of the same species with de- 

 crease in latitude, and of their comparatively darker plumage 

 in the southern than in the northern borders of their habitats, 

 of which instances are given. 



2. Geographical Variation in North-American Birds. Proc. 

 Bost. Soc. N. H. xv. pp. 212-219. 



Mr. Allen seeks to give the general results that have fol- 

 lowed upon the investigation of the large series of specimens 

 of North-American birds in the Smithsonian Institution 

 and Museum of Comparative Zoology. These results, as al- 

 ready shown by the author in previous papers (Bull. Mus. 

 Comp. Zool. ii. no. 3, and iii. no. 6), prove that ' ' intergrada- 



ser. in. — VOL. III. 2 H 



