254 



REPTILIA 



CLASS III 



Dermodadylm, Marsh. Imperfectly known, perhaps belonging among the ^ 

 Pterodermata. Upper Jura (Como Beds) ; Wyoming. 



Fio. 359. 



J'terodactijlus elegans, Wagner. Lithographie Stone ; 



Eichstäclt, Bavaria. Vi- 



Fig. 360, 



Pterodactyhis spectabüis, v. Meyer. Lithographie 

 Stone ; Eichstädt, Bavaria. '-^/^ (after H. v. Meyer) 



Family 2. Ornithocheiridae. Seeley. 



External nares confluent with antorbital vacuity. Teeth, when present, restrided 

 to posterior portimi of the jaws. Pectoral arch strong, coracoids and scäpulae firmly 

 fused ; the former articulating with the sternum, and the latter hy a large oblique 

 facette with a supraneural plate above the coössified anterior dorsal verlebrae. Proxi- 

 mal tarsals fused with the tibia; no fibula. Cretaceous. 



This family includes the largest known Pterosaurs, their wing expanse 

 varying between \'b and 5 '8 m. In these highly specialised forms the anterior 

 extremities attained their greatest power, while the posterior pair were 

 weakened, and probably of slight use as locomotive orgaiis. 



Fteranodon, Marsh (? Ornithostoma, Seeley). Skull considerably elongated, 

 with slender, pointed, edentulous jaws, and a long thin supraoccipital crest. 

 Sclerotic ring present. Sternum keelless, but with a stout anterior median 

 projection. Sacral vertebrae seven in number. Anterior ribs stout, 

 coössified with their centra. Carpus composed of three bones in two rows. 

 Pubes band-like, coössified in the middle. Hind limbs relatively small ; 

 femur short and curved, with a small trochanter ; tarsus consisting of two 

 free bones in a single row. Fifth digit represented by a small claw-like 

 metatarsal ; median phalanges of second, third, and fourth digits very short ; 

 first and second digits without claws. Niobrara Cretaceous ; Kansas. 



