A STUDY OF CHIONIS MINOR WITH REFERENCE TO ITS STRUC- 

 TURE AND SYSTEMATIC POSITION. 



By J. H. Kidder, U. S. N., and Elliott Coues, U. S. A. 



" This small family of birds \_Thmoclwrus, Attagis, and Chionis'\ is one of those which, 

 from its varied relations to other families, although at present offering only difficulties 

 to the systematic naturalist, ultimately may assist in revealing the grand scheme, 

 common to the present and past ages, on which organized beings have been created." 

 (Darwin, Voyage of a Naturalist, Neiv York, 1871, p. 94.) 



CHaOI¥IS MIIVOR, Hartlaub. 



Sheath-bill ; Bec-en-fourreau. 



HISTORY. 



The genus Chionis was founded by J. R. Forster in 1788,* upon C. alba, 

 discovered by bim in the neighborhood of Cape Horn. In January, 

 1841, Dr. G. Hartlaub wrote from Bremen to the Revue Zoologique t 

 that he had discovered a new species of Chionis in the museum at Ley- 

 den. He described it as differing from C. alba by its decided inferi- 

 ority in size, by the blackness of the entire beak, and particularly by 

 the extraordinary shape of the sheath of the bill. His original descrip- 

 tion and measurements are as follows : 



"Chionis minor, JVb&., nivea, rostro nigerrimo, pedibus saturate fusces- 

 centibus, spatio snpraoculari subrotundo, nudo, nigro, rostri vagina suh- 

 co7icavd, antrorsum ascendente, apertd {in Ch. albdj plana, incumbente). 



C. minor. 



C. alba. 



Long, total 



rostri a /route 



Altit. rostri ad basin 



Latitud. rostri ad angiilum oris 

 Long, alee 



tarsi 



candce 



digiii med'vi 



* Enchiridion Hist. Nat. Ins. 1788, p. 37. 



t Rev. Zool., 1841, o. 5; ib. 1842, pi. 2, fig. 2. 



85 



