,0.1320. NOTES ON FOSSIL BIRDS— LUCAS. 555 



The tarsus is stout and somewhat compressed hiterally; although 

 iveathered there ai)pear to have been no tendinal o-roovos, much less 

 my tendinal foramina, these hist marking a degree of tarsal specializa- 

 tion vastly higher than was possessed by any Cretaceous bird. If it is 

 permitted to borrow a little of the style of W. K. Parker it might be 

 said that the early birds show a great deal of reptilian coarseness in 

 their articulations, and lack the detail and sharpness of finish that 

 eame later and marks a higher degree of specialization. The lower 

 end of the tarsus ])ears a faint imprint of the presence of tlie small 

 first digit, but still as much as exists in some ducks. The phalangeal 

 articulations are narrow, indicating compressed digits; this is also 

 shown by the proximal fragment of a median digit. Compressed 

 digits are now associated with lobate feet, and thus, so far as we know, 

 the lobate foot preceded the webbed foot in point of time. Our 

 knowledge of early birds is, however, so trivial that it is scarcely 

 worth while to make any generalizations on this subject, the more that 

 there is no reason why the two types of foot may not have been evolved 



■piG. 8. — Right i'adella of Baptornis udrniiis, natural size. 



independently of one another. The waders indeed suggest that the 

 evolution was independent, as this group shows the beginning of such 

 feet in such forms as the phalarope and avocet. 



In the length of the coracoid and absence of a precoracoid process; 

 in the existence of a complete though greatly reduced wing; the short- 

 ness of the sacrum; proportions of the leg bones and position when m 

 use, Baptornis is very different from Hesperornis and more like exist- 

 ing birds. In the slender cervicals, arrangement of tibia and patella, 

 and general structure of the le^- Baptornis is more like a grebe than 

 is the contemporary Hesperornis, and if, with the small amount of 

 material available, it is deemed essential to establish any connection 

 between groups of existing and fossil birds it is suggested that the 

 ancestors of Baptornis are much more likely to have been also the 

 progenitors of the Colymbine group than are those of Hesperornis. 



It is certain, as said near the l)eginning of the notes on Baptornis, 

 that this bird belongs in an entirely different family from Hesperornis, 

 and if it is ever given to us to know more of the bird it may prove 

 to belong in a separate order. 



