Recently published Ornithological Works. 385 
of Paradise-birds in the Tring Museum, which, if we include 
the Bower-birds, contains eggs of 23 different forms. Notes 
are given as to where and how they were obtained. 
A full plate (pi. x.) contains figures of these beautiful 
objects, 
40. Hellmayr on the Species of Percnostola. 
[Uebersicht der Formen der Gattung Percnostola. Von C. E. Hellmayr. 
Verh. Orn. Gesellsch. Wien, viii. p. 140.] 
Mr. Hellmayr writes on Percnostola , a Neotropical genus 
of Formicariidae. Of this he admits only two of the older 
species (P. rufifrons and P. r. minor) as subspecies, and 
adds a third new subspecies— P. r. subcristata from the 
Bio Negro. 
41. Hellmayr on the South-American Species o/Chsetura. 
[Uebersicht der sudamericanischen Arten der Gattung Chcetura 
(s. str.). Von 0. E. Hellmayr. Verb. Orn. Gesellsch. Wien, viii. p. 145.] 
The author enumerates 12 South-American species and 
subspecies of this genus of Swifts, and gives full descriptions 
and synonymy of each of them. But we confess our inability 
to understand upon what grounds he calls some of them 
“ species” and others “ subspecies.” He seems to place 
them all on an exact equality. 
42. Hellmayr on the Birds of the Rio Madeira. 
[The Birds of the Rio Madeira. By 0. E. Hellmayr. Nov. Zool. 
xvii. no. 3 (Dec. 1910].] 
This memoir gives us a complete and well-prepared 
account of the collection of birds made by the late Mr. W. 
Hoffmanns in various localities on the Upper Bio Madeira, in 
1897 and 1898. The specimens, or most of them, are in the 
Thing Museum. Mr. Hoffmanns had made a previous 
collection in the same district, of which Mr. Hellmayr wrote 
an account in the ‘Novitates Zoologicse' in 1907 (vol. xiv. 
p. 343). On that occasion also a large selection went to the 
Tring Museum. Thus, Mr. Hellmayr had a fine series of some 
2000 specimens to work upon, and the present article, in 
