/2 GEOLOGICAL MEMOIRS. 



On the Pterodactylus (Rhamphorhynchus) Gemmingi, from 

 the Calcareous Slates of Solenhofen. By Hermann von Meyer. 



[Extracted from ' Paleontographica : Beitrage zur Petrefaktenkunde' Herausgege- 

 ben von Dr. W. Dunker und Hermann von Meyer, 1 Heft.] 



That period in the history of the earth whose records are preserved 

 in the Oohte or Jura formations, from the Lias up to the Wealden, 

 may be named the Middle Ages of geological chronology. This long- 

 epoch may be regarded as the time of Saurian dominion, these ani- 

 mals having then exhibited a richness of forms unequalled at any 

 other period. For although these reptiles appear in many remark- 

 able forms in the immediately preceding formations of the Trias, 

 still in them we find no proofs of the existence of whole orders of 

 Saurians which arose with the oolite group, and again vanished with 

 its close ; and in no period have the Saurians been poorer in forms 

 than in the interval extending from the commencement of the ter- 

 tiary deposits to the present time. This geological Middle Age is 

 adorned by the Pterodactyles or Flying Saurians, whose earliest re- 

 mains are found in the Lias, the latest in the Wealden, thus marking 

 out the limits of this epoch. 



Various views have been maintained regarding the nature of the 

 Pterodactylus. CoUini in 1784, when investigating the characters 

 of the Pt. longirostris, was inclined to consider the animal as a fish. 

 The Pterodactyles were however no more fish than they were birds, 

 as Blumenbach in 1807 made them; or mammalia, among which 

 they were placed by Sommering three years later. Spix considered 

 these animals as intermediate between Galeopitheci and the bats ; 

 Macleay as a connecting link between mammalia and birds ; Wagler 

 formed from the Monotremata together with Pterodactylus, Ichthyo- 

 saurus and Plesiosaurus, a fifth class of verteb rated animals, which 

 he placed between the mammalia and birds ; and in regard to the 

 Pterodactylus he also believed that its feet were fin-shaped, like 

 those in the marine tortoises or the small eared seal {Otaria pusilla). 

 Even iVgassiz believed it an error to consider the Pterodactylus as a 

 flying reptile. According to his view the whole organization of the 

 animal was such, that it must have lived in the water along with the 

 Ichthyosaurus and Plesiosaurus ; and from these beings, so very 

 different in structure, he formed one family, that of the Palaeosau- 

 rians. A long-continued study of the very interesting structure of 

 these animals has only the more convinced me of the accuracy of the 

 views published by Cuvier so early as the year 1800. The Ptero- 

 dactyles were flying Saurians. The pneumatic structure of the 

 bones, the connexion of the vertebral ribs with the sternum by 

 means of osseous ribs, the osseous processes of the ribs in order to 

 confer greater firmness on the chest, formed of the chief ribs, the 

 sacral bone made up by the anchylosis of a great number of verte- 

 brae, as well as the circumstance that in the posterior limbs the tibia 

 is the longest bone, so strikingly recall the structure of birds, that it 

 seems almost incomprehensible how any one can doubt that they 



