PTEKODACTYLID.E. 



Suborder PTERANODONTIA. 



Teeth absent ; cranium (fig. 1) with a long, backwardly-pro- 

 duced supraoccipital crest, and nares completely confluent with 



Fig. 1. 



Pteranodon longiceps, Marsh. — Left lateral view of skull; from the Cretaceous 

 of North America. T V a, preorbital vacuity; b, orbit ; c, supraoccipital 

 crest ; d, angle of mandible ; q, quadrate ; s, symphysis. (After Marsh.) 



preorbital vacuity. Scapula generally articulating with spines of 

 dorsal vertebrae, which are anchylosed together. 



This Suborder is at present unrepresented in the Collection. 



Suborder PTEROSAURIA. 



Teeth in both jaws ; cranium without backwardly-projecting 

 supraoccipital crest, and with the nares usually more or less com- 

 pletely separated from the preorbital vacuity. Scapula (at least 

 usually) not anchylosed to spines of dorsal vertebrae, which are 

 distinct from one another ; four phalangeals in ulnar digit of 

 maims. 



Family PTERODACTYLID^E. 



Tail short ; skull bird-like, either long or short ; jaws toothed 

 to their anterior extremity; nares usually large, and imperfectly 

 separated from preorbital vacuity ; length of metacarpus considerably 

 exceeding half that of ulna ; proximal half of tarsus distinct from 

 tibia. 



Genus PTENODRACON *, Lydekker. 



Skull very short, and the muzzle not produced into a rostrum ; 

 teeth confined to anterior extremity of jaws ; nares and preorbital 



1 Seeley (' Ornithosauria,' p. Ill) proposed to use Ornithoecphalus in this 

 sense, an application which has been shown by Zittel (' Palseontographica,' 

 vol. xxix. p. 80) to be inadmissible. 



b2 



