EXPLANATION OF PLATES 



The material figured in the 16 plates illustrating the present treatise 

 belongs either to the collection of the United States National Museum at 

 Washington, D. C. or is a part of the private collection of the author now 

 in the New York State Museum. The figure of the Secretary-bird (pi. I, 

 fig. i) is from a photograph of the mounted specimen in the Museum made 

 by Prof. T. W. Smillie, the accomplished photographer of that institution 

 (no. 12314). All the other figures are from photographs made by the 

 author direct from the specimens. The material shown in figures 2 

 (no. 13823), 3 (not numbered), 4, 5 (no. 18997), 6, 7 (no. 17834), 8 (no. 

 19009), 10, 12 (no. 18222), 20, 21 (no. 17834), 22, 23, 24, 25, 26 (no. 17836), 

 27, 30, 31, 32 and 33 are from the first mentioned collection, while all the 

 rest are specimens from the author's material. I desire to express my 

 thanks in this place for the use of these very valuable osteological speci- 

 mens, and especially to Mr Lucas for his kindness in having them so 

 promptly placed at my disposal, and for his having the skull of the Califor- 

 nian condor prepared for my special use [fig. 2]. Where bones have 

 belonged to the same individual the fact will be stated under the figure of 

 any particular plate where they are described. When not otherwise 

 stated, all the figures in the text and in the plates, were made by the 

 author. 



Plate 1 

 137 



