order ix PTEROSAURIA 253 



antorbital vacuity. Proximal phalanx of wing digit more than double the 

 length of antebrachium. Type, C. zitteli, Plieninger. Palate and 1 train cast 

 known in 0. purdoni, Newton, from the Upper Lias of Yorkshire. 



Scaphognathus, Wagner. Like the preceding, but mandibular rami toothed 

 quite to the extremity, and not deflected. External nares smaller than the 

 antorbital vacuity. S. crassirostris, Goldfuss, the type species, occurs in the 

 Lithographic Stone of Bavaria. 



Bhamphorhynchus, v. Meyer (Figs. 354, 356, 358). Skull sometimes attain- 

 ing a length of 20 cm. Snout produced and acuminate ; teeth large, irregular, 

 inclined forwards, and not extending to anterior end of the jaws. Orbits very 

 large, with sclerotic ring ; narial opening and antorbital vacuity very small. 

 Four sacrals and upwards of forty caudals present. Sternal keel extending 

 downward as a slender process, scapula and coracoid usually fused. Pubis in 

 the form of a slender bar, bent inwards nearly at right angles to meet its 

 fellow, with which it fuses in a median symphysis. Limbs similar to those of 

 Dimorphodon, except that the fifth toe comprises three phalanges. Upper 

 Jura (Lithographic Stone) ; Bavaria and Wiirtemberg. 



Sub-Order 2. ORNITHOCHEIROIDEA. Seeley. 



Tail short ; wing metacarpal at least as long as the bones of the antebrachium; fifth 

 digit of pes vestigial, without phalanges. Teeth sometimes absent. No cervical ribs. 



The members of this sub-order vary greatly in size, some being no larger 

 than a sparrow, and the largest having a wing expanse of nearly 6 m. 

 Initiated in the Upper Jura, the group culminated in the Upper Cretaceous, 

 and became extinct before the close of that period. This sub-order probably 

 includes all known forms of Cretaceous Pterosaurs. 



Family 1. Pterodactylidae. 



Skull with very small lateral temporal vacuities, and large external nares incom 

 pletely separated from the antorbital vacuity. Coracoid and scapula separated, the 

 distal end of the latter spatulate, and not articulating with vertebral column. Antt rior 

 dorsal vertebrae without supraneural plate. Elements of carpus and tarsus distinct. 

 Teeth,' when present, extending to extremity of jaws. Upper Jura and Cretaceous. 



Pterodactylus, Cuvier (Omithocephalus, p.p. Somm. ; Diopecephalus, Cycno- 

 rhamphus, Seeley; Ptenodracon, Lyd.), (Figs. 355, 359, 360). Teeth invariably 

 present. Eepresented by numerous species varying in size between that of a 

 sparrow and that of an eagle. The most perfectly preserved skeletons occur 

 in the Lithographic Stone of Bavaria, Wurtemberg, and Cerin, France. 

 Certain detached fragments from the Kimmeridge Clay of England are perhaps 

 referable to this genus. 



Nyctodactylus, Marsh (Fig. 361). Known by a nearly complete skeleton from 

 the Xiobrara Cretaceous of Kansas. Head slender, jaws edentulous. Lateral 

 pieces of atlas not fused with axis ; cervicals seven, dorsals twelve, sacrals 

 six, caudals ten to fourteen. Anterior ribs stout, double-headed ; posterior 

 very slender and single-headed ; three pairs of flat V-shaped abdominal ribs 

 connecting the xiphisternal process with the anterior processes of the coossified 

 pubes. Ischiadic foramen very large. Proximal row of tarsals united to tibia 

 by persistent suture; three carpals present. Wing expanse in typical species 

 about 2 m. 



