CRETACEOUS FORMATIONS. 



19 



4to, 1851, e.g., is 2 inches 2 lines; that of the wing-bone, figured in Tab. IV, figs. 

 1 — 3 of tlie present Monograph, is 3 inches. The transverse diameter of the distal 

 end of the humerus of Pterodactylus granclis, Cuv., the largest species hitherto 

 obtained from the Lithographic Slates of Grermany, is 1 inch 3 lines ; neither the 

 radius, ulna, or metacarpal of the wing-bone of the same species presents a diameter 

 of its largest end equalling 1 inch.* 



The articular end of the long wing-bone, (Tab. IV, figs. 1 — 3), being most pro- 

 bably that of an antibrachial bone, and the total length of the bone, whether radius 

 of ulna, being, according to proportions of either of these bones in Pterodactylus 

 suevicus, 16 inches, the following would be the length of the other long bones of the wing 

 in the large Pterodactyle to which the above-cited specimen belonged, according to the 

 proportions which those bones, bear to the radius or ulna in Pterodactylus suevicus. — 



Humerus . 



Radius 



Metacarpus of wing-finger 



First phalanx of do. 



Second do. do. 



Third do. do. 



Fourtli do. do. 



Total length of long-bones of one wing 



•■t. 



In. 



Lines 



t 











1 



4 







1 



8 







2 



3 







1 



9 







1 



J 







1 



1 







10 



Supposing the breadth of the Pterodactyle between the two shoulder-joints to be 

 8 inches, and allowing 2 inches for the carpus and the cartilages of the joints of the 

 different bones, in each wing, we may then calculate that a large Fterodactylus Sedgwickii 

 would be upborne on an expanse of wings of not less than 22 feet from tip to tip. 



I look forward with confidence to future acquisitions of remains of the truly 

 gigantic Pterodactyles of the cretaceous periods, more especially from the Green- 

 sand locality near Cambridge, as a means of throwing more light on the peculiar 

 osteology of the extinct flying reptiles. 



For the opportunities at present afforded me, I have to express most grateful 

 acknowledgments to my old and much esteemed friend the Rev. Professor Sedgwick, 

 F.R.S. ; to the acute and active curator of the Woodwardian Museum, Mr. Lucas 

 Barrett, F.G.S. ; to James Carter, Esq., M.R.C.S., Cambridge ; to T. W. Beddorae, 

 Esq.. of Trinity College, iL'ambridge ; and to the Rev. G. D. Liveing, M.A., of St. John's 

 College, Cambridge ; to whom I am indebted for the lower jaw of Pterodactylus 

 Sedgwickii (Tab. I, figs. 2, a, b, c, d). 



* These admeasurements are derived from the excellent figures of a recently acquired specimen, well 

 described by Professor Andreas Wagner of Munich, in the " Abhandlungen der Kais. Bayer. Akademie 

 der Wissenschaft," Band, iii, p. 603, taf. xix. 



