The Flying Lizards of the Secondary Rocks. 451 



" Supposing the breadth, of the Pterodactyle between the 

 two shoulder-joints to be eight inches, and allowing two inches 

 for the carpus and the cartilages of the joints of the different 

 bones in each wing, we niay then calculate that a large P. b'edg ■ 

 wickii would be upborne on an expanse of wings not less than 

 22 feet from tip to tip." 



In the Palfeontographical Society's Publications, Supple- 

 ment ~No. 3, already referred to, Professor Owen says, " 1 am 

 now enabled to adduce, from more recently acquired additions to 

 the Woodwardian Museum at Cambridge, evidences of a much 

 larger Pterodactyle, distinct from any previously known, and 

 which must have acquired at least double the dimensions of 

 P. Sedgwickii. ,} 



Professor Owen describes and figures remains of two other 

 species of chalk Pterodactyles, P. Ouvieri and P. compressirostris, 

 larger than P. giganteus of Bowerbank. This, however, still 

 belongs to the race of the giants. 



Evidence of a long tail in the Chalk species has not yet been 

 met with ; but from the number of detached caudal vertebras 

 found in the Cambridge Greensand, Professor Owen believes 

 the P. SedgwickU " had a long but moveable tail/'' 



When looking at the skeleton of the Pterodactyle one is 

 apt to fancy, for an instant, " here is a reptile trying to become 

 a bird •" and the first glance at the Archceopteryx might sug- 

 gest the notion that here it had succeeded in the attempt ; but 

 a more careful consideration of the subject will not fail to 

 convince us that the Pterodactyle bird and bat are no less 

 essentially members of distinct classes of animals because they 

 are gifted with the common faculty of flight. 



Thirty- seven species of flying lizards are known and de- 

 scribed; how many individuals have been discovered it is 

 impossible to say. There is every reason, however, to believe, 

 from the frequent occurrence of their remains, that they were 

 very abundant in the Mesozoic period. 



We are not justified, however, in considering that they alto- 

 gether took the place of birds ; on the contrary, the discovery 

 of the Archoeopteryx proves them to have been contempora- 

 neous races so far back as the upper Oolitic age. 



All the mammals we are acquainted with in rocks of 

 the Secondary period belonged to small animals obscurely 

 resembling the lowest of existing quadrupeds. Their place in 

 nature appears to have been filled by orders of reptiles, some 

 of them now extinct. The gigantic Dinosaurians represented 

 the land quadrupeds ; Bnaliosaurians took the place of whales, 

 and the Pterodactyles of bats, and 'partially of birds, thus realiz- 

 ing Dr. Mantel!' s vision of an " Age of Reptiles." 



