BIRDS OF THE ROCKS. 171 



and from calcareous shale near Fort Wallace, 

 is named Hesperornis regalis. Under the gen 

 eric name Hesperornis have been grouped a 

 number of species represented by skeletons 

 more or less lacking completeness, but nearly 

 enough perfect to show their affinities. A 

 genus Ichthyornis of most remarkable toothed 

 birds has been found in the middle cretaceous 

 rocks of Northwestern Kansas, and a number 

 of interesting remains have been taken from 

 the green sand and marl beds in New Jersey. 

 It would not serve any purpose to catalogue 

 here all the known fossil birds. I have hastily 

 sketched a broken outline by way of preface, 

 leading up to what geologists call the tertiary 

 rocks. Here we find the true ancestry of our 

 present birds the rocks begin to sing and 

 twitter and chirp. Now we hear a far-away 

 chorus, the morning voices from the old, old 

 woods. A very breath of flowers and foliage 

 is suggested. 



In the Museum of the Boston Society of 

 Natural History is preserved a beautiful speci 

 men from the insect-bearing-shale of Colorado, 

 containing a nearly complete skeleton (with 

 feather impressions of wings and tail) of a 

 bird belonging to the &quot; oscine division of the 

 Passeres&quot; a division which contains all the 

 singing birds now existing. This discovery of 

 an oscine bird in the fossil form, dating far 

 back of the age of man, leads the poet, not the 

 scientist, to ask whether it may not be possi 

 ble, and even probable, that some of the more 

 ancient fossil birds had that peculiar structure 

 of the lower larynx, or syrinx, necessary to the 

 songster. The oscines are not toothed birds, 

 and teeth have been considered an index of a 



