ORDER ORNITHOSAURIA. 



1 199 



were completely confluent with the preorbital vacuities. According 

 to Professor Marsh, these reptiles were mostly of gigantic size ; some 

 having a spread of wing of nearly or quite 25 feet. And in order 

 to aid the powerful patagium in flight, the pectoral girdle was 

 generally strengthened by the anchylosis of several vertebras, and 

 by the robust scapulae articulating to the spines of these anchylosed 



Fig. 1096. — Left lateral view of the skull of Pteranodon lotigiceps] from the Cretaceous of 

 North America. One-twelfth natural size, a, Nares and preorbital vacuity ; b, Orbit ; c, 

 Supraorbital crest ; d, Angle of mandible ; q, Quadrate ; s, Symphysis (After Marsh.) 



vertebrae ; this peculiar feature being virtually a repetition of the 

 pelvic girdle and sacrum on a much larger scale. 



Family Pteranodontid^. — The type genus Pteranodon (fig. 

 1096) occurs in the Cretaceous of North America; and although 

 its members are generally of large size, it is also represented by one 

 small species — P. nanus. The coracoid and scapula were united, 

 but the oral aspects of the jaws have not the ridge and groove 

 found in Omithochirus. Ornithostoma, of the Cambridge Green- 

 sand, may have been an allied form. In Nyctodactylus, of the North 

 American Cretaceous, Professor Marsh thinks that none of the 

 dorsal vertebrae were anchylosed ; and on this account the genus 

 should perhaps form the type of a distinct family. 



Suborder 2. Pterosauria. — In this, the typical, suborder teeth 

 are present in both jaws ; the cranium (fig. 1097) has no long supra- 

 occipital crest directed backwards, and generally has the nares more 

 or less completely separated from the preorbital vacuities. The 

 scapula is (at least usually) not anchylosed to the neural spines of 

 the dorsal vertebrae, which are distinct from one another. This sub- 

 order is mainly European. 



Family Pterodactylltle. — In the typical family the tail is 

 short (fig. 1097); the jaws are toothed to their extremities; and 

 the length of the metacarpus considerably exceeds half that of the 

 ulna (fig. 1097). The skull, which is extremely bird-like, may be 

 either long or short, and has the nares imperfectly separated from 

 the preorbital vacuities ; while in the pelvic limb the astragalus is 

 always distinct from the tibia. In Europe this family is especially 

 characteristic of the Upper Jurassic, and is abundantly represented 

 in the Lower Kimeridgian lithographic limestones of Bavaria, which, 



