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 {_Thinochorus, 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, New York, 1871,2?. 94.) 



CffllOMIS MIIVOR, Hartlaub. 



Sheathbill; Bec-en-fotjrreatj. 



HISTOEY. 



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

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

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

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

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

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



m 



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

 tion and measurements are as follows: 



"Chionis minoe, JSfob., nivea, rostro nigerrimo, pedibus saturate fmces- 

 centibus, spatio supraoculari subrotundo, nudo, nigra, rostri vagina sub- 

 concava, antrorsum ascendente, apertd {in Ch. alba, plana, incumbente). 



Long, total 



rostri a fronte 



Altit. rostri ad basin 



Latitud. rostri ad unguium oris 

 Long. alo3 



tarsi 



Cauda 



digiii medii , 



C. alba. 



3 

 4 



8 

 7i 



11 



lig. 



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

 tEev. Zoiil., 1841, v. 5; ib. 1842, pi. 2, fig. 2. 



85 



