]78 Recently piihllslied OrniiJiohjical Jl^orks. 



in plumage details. The explanation and significance of 

 this phenomenon is still to be sought. 



Among strictly systematic papers continued in the present 

 volume is one by Mr. F. M. Chapman on the genus Scyta- 

 lopus of the Neotropical family Pteroptochidse. These birds 

 are exceedingly shy and retiring, of mouse-like habits? 

 and live in the dense undergrowth of the Andean Forest. 

 They are consequently exceedingly rare in collections. 

 Mr. Chapman reviews the species found in the northern 

 ])arts of South America and proposes four new species — 

 S. canus, S. infasciatus, S. sancta-martce, and S. paramensis, 

 and a new generic name Myornis for S. senilis (Lafr.). 



In a study of the migration routes by which birds reach 

 the Mackenzie Valley of north-west Canada, Mr. W. W. 

 Cooke finds that the larger proportion of the summer birds 

 of this region come from the Mississippi Valley, and com- 

 paratively few from California and the country west of the 

 Kocky Mountains. He has been able to construct what he 

 calls isochronal lines, showing on the map the latitudes 

 reached on any particular date in the northward movements 

 of a species ; if these are correctly plotted they show very 

 clearly the route of the migration of a species. 



A series of five articles on the early history and distri- 

 bution of the Wild Turkey in North America, commenced 

 in the previous volume by Mr. A. H. Wright, are now 

 brought to a close. 



There are many other papers Avhich we should like to 

 notice, but space forbids. We would like to draAv attention, 

 however, to an appreciative memoir of Theodore N. Gill 

 (1837-1914), whose death was not noticed in the pages of 

 ' The Ibis.' Though chiefly known as an ichthyologist, 

 he wrote largely on other subjects and at one time owned 

 and edited an ornithological journal, 'The Osprey.' He was 

 described by Dr. Jordan as " Master of Taxonomy," while 

 Prof. Baird characterised him as " the most learned of 

 American naturalists. '■" 



