THE GREATEST FLYING CREATURE. 657 



so the greatest of these pterodactyls were the largest creatures that ever 

 flew, their outstretched wings having a spread of 20 feet from tip to tip. 



There is one possible rival, a bird supposed to be a relative of the 

 pelicans, described by Professor Cope under the name of Cyphorms; 

 but as this bird is known from a small fragment only and its wing area 

 very far from certain, Cyphornis may be ruled out of competition. 



The greatest of the pterodactyls. Omithostorna ingens (PI. VI), has 

 hern described at some length by Prof. S. YV. Williston, of the State 

 University of Kansas, and from his articles have been taken the facts 

 relating to this curious creature that are herein embodied. 



The great moa marks one extreme of specialization, the dispropor- 

 tionate size of the hind as compared with the fore limbs, for this big 

 bird had legs feet long and no fore legs at all; Omithostorna marks 

 the other extreme with a wing 9 feet in length and a leg so small and 

 weak as to be of little use save for spreading the wing membrane. 

 For, like other pterodactyls, whose wings are accurately known from 

 their impressions in the fine-grained lithographic stone of Solenhofen, 

 this species doubtless had a membranous wing- something like that of 

 a bat. As for the body, being that of a reptile, it must have been 

 naked and possibly covered with small scales like those on the body of 

 an iguana, so that on a small picture the skin would appear quite 

 smooth. While the body was small in comparison with the extent of 

 wing, the head, which was principally beak, was very nearly -i feet 

 long, extending backward to form a large but thin crest. This has a 

 direct relation to the enormous length of the beak, since it furnished 

 a point of attachment for muscles whose pull counterbalanced the lever- 

 age of the front part of the head. The beak was dagger-like, being- 

 very narrow, pointed, and quite toothless. Whether this beak was 

 covered with a thin, hard skin, like the epidermis on the head of a 

 crocodile, or with horn, like the bill of a bird, is not positively deter- 

 mined, but the weight of evidence is in favor of the former, since none 

 of the pterodactyls yet found show any traces of a horny bill. In the 

 peculiar shape of the lower, back portion of the beak there is ;i sug- 

 gestion of the former presence of a small pouch, like that found in 

 cormorants, and this would be in accord with the supposed fish-eating 

 habits of Omithostorna. Like other animals with long, narrow wings, 

 Omithostorna doubtless sailed somewhat after the manner of the alba- 

 tross. This is inferred not only from the size and shape of the wing, 

 but from the comparatively small size of the breastbone, to which 

 were attached the muscles used in flight. Birds which rly by strokes 

 of their pinions have the breastbone deeply keeled to furnish room for 

 the attachment of the wing muscles, and the size of this keel is in 

 direct relation to the rapidity of the wing strokes, reaching its maxi- 

 mum in the humming birds, in which the wings are vibrated so rapidly 

 as to be invisible. Birds Avhich sail have the breast muscles much 

 sm 1901 42 



