ALLEN ON A NEW FOSSIL PASSEETNE BIRD. 445 



The larger specimen, first clescribetl, is divided into an upper and a 

 lower half, the greater part, however, adhering to the lower slab. The 

 bones adhere about equally to the two faces. The drawing is made from 

 the lower slab, with some of the details filled in from the upper one. 

 The feather impressions are about equally distinct on both, and where 

 in either case the bones are absent, exact molds of them remain, so that 

 the structure can be seen and measurements taken almost equally well 

 from either slab, except that nothing anterior to the breast is shown on 

 the upper slab. 



The species here described is of special interest as being the first fos- 

 sil Passerine bird discovered in North America, although birds of this 

 group have been known for many years from the Tertiary deposits of 

 Europe. The highest extinct ornithic tyjie hitherto known from 

 America is a Picarian bird ( Uintornis lucaris') related to the Woodpeckers, 

 described by Prof. O. C. Marsh in 1872, from the Lower Tertiary of 

 Wyoming Territory. Probably the insect-bearing shales of Colorado 

 will afford, on further exploration, other types of the higher groups of 

 birds. 



For the opportunity of describing these interesting specimens I am 

 indebted to Mr. S. H. Scudder, who obtained them during his last sea- 

 son's (1877) explorations of the Florissant insect-beds. The specimens 

 are now the property of the Boston Society of Natural History. My 

 thanks are due to Mr. J. H. Blake for the great care with which he has 

 executed the drawings. 



In conclusion, I may add that in 1871 1 obtained a few distinct impres- 

 sions of feathers from beds of the same age and from near the same 

 locality. The first fossil feather, to my knowledge, discovered in North 

 America was obtained by Dr. F. V. Hayden in 1869, from the fresh- 

 water Tertiary deposits of Green Eiverj Wyoming Territory. This was 

 described by Professor O. C. Marsh in 1870,* who refers to it as " the 

 distal portion of a large feather, with the shaft and vane in excellent 

 preservation ". 



* Am. Journ. Sci. and Arts, 2d. ser., vol. xi, 1870, p. 272. 



