342 Recently ].uhlished Ornithohyical Works. 



53. Hartert on an overlooked Swift. 



[On an ovcrlookod Indian Swift. By Ernst Hartert. Ornis, xi. p. 199.] 



The resuscitated Swift is Cypselus acuticauda of Jerdon 

 (B. Ind.^Suppl. p. 870, 1864), which iu the B. M. Catalogue 

 (xvi. p. 444) has been united to Micropus apus pekinensis. 

 Mr. Hartert has now found a second specimen in the Tring 

 Museum (from Cherripungi, Khasia Hills), which he has 

 compared with the type in the Liverpool Museum (from 

 Nepal) and found to be identical with it. He calls it Apus 

 acuticauda, and describes its characters. We prefer to call 

 it by Blyth^s name Cypselus acuticauda. 



54. Hartert and Hellmayr on two new Thrushes. 



[On two new Thrushes from Western Colombia. By Ernst Hartert 

 and Carl E. Hellmayr. Nov. Zool. viii. pp. 492, 493.] 



Turdus ignobilis goodfellowi, from the Cauca valley of 

 Colombia, and T. colombianus (a southern representative of 

 T. obsoletus, but nearly allied to T. tiigi-ii'ostris), from Cali, 

 Western Colombia, are described as new. 



55. Helm on some Birds of Heligoland. 



[Ueber einige ornithologische Beobachtungen auf Helgoland. Von F. 

 Helm. Ornithol. Monatsb. ix. pp. 149-161.J 



This paper treats of the Starling, Linnet, Swift, Hooded 

 Crow and Wild Duck, as" noticed on Heligoland. 



56. Helm on the Flight of Birds. 



[Betrachtungen Uber die Beweise Gatke's fiir die Hohe und Sclmel- 

 ligkeit des Wanderfluges der Vogel. Von F. Helm. J. f. O. 1900 

 pp. 435-452. ' ' 



Weitere Betrachtungen iiber die Beweise Gatke's fiir die Ilohe und 

 Schnelligkeit des Wanderfluges der Vogel. Von F. Helm. J. f. 0. 1901 

 pp. 289-303.] ' " ' ' 



Herr Helm considers that, although we may agree with 

 many of Gatke's statements regarding the flight of Birds, 

 certain of his conclusions are most surprising, and are founded 

 on premisses which may be shown to be false. Especially 



