8 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 28, 



In my communication to the Society in May last, I have stated 

 that I believed it probable that these bones were parts of a tibia, 

 but on a more careful comparison with the figures of Pterodactylus 

 by Goldfuss, 1 am inclined to believe they are more likely to be 

 portions of the ulna. 



It is unfortunate for the comparison of the specimens that the 

 bone belonging to Lord Enniskillen is deficient in that end in which 

 mine is most perfect, and that the bone in my possession wants the 

 end in which the former is nearly perfect, so that in reality the 

 whole weight of the comparison is dependent upon the similarity- 

 existing in the shafts of the two bones. 



The flat side of the bone described by Professor Owen is rather 

 more rounded at that portion exhibited by cutting away the chalk 

 beneath it, but it gradually becomes less convex as we pass towards 

 the same relative portion that is exposed in my specimen ; and the 

 expansion towards the large extremity of the bone, represented by 

 fig. 6, corresponds, as nearly as can be determined by the mutilated 

 condition of the specimen, with the large extremity of the bone be- 

 longing to the Earl of Enniskillen. 



If the part of the head in my possession (see fig. 1 ) be supposed 

 similar in its proportions to that of Pterodactylus crassirostris, — 

 and there appears but little difference in that respect, — it would in- 

 dicate an animal of comparatively enormous size. 



The length of the head from the tip of the nose to the basal ex- 

 tremity of the skull of P. crassirostris is about 44 inches, while my 

 specimen would be, as nearly as can be estimated, 9\ inches. 



According to the restoration of the animal by Goldfuss, P. eras- 

 sirostris would measure as nearly as possible three feet from tip to tip 

 of the wings, and it is probable that the species now described would 

 measure at least six feet from one extremity of the expanded wings to 

 the other ; but if it should hereafter prove that the bone described 

 and figured by Professor Owen belongs to a Pterodactyl^ the probable 

 expansion of the wings would reach to at least eight or nine feet. 



Under these circumstances, I propose that the species described 

 above shall be designated Pterodactylus giganteus. 



May 28, 1845. 



J. A. Hankey, Esq., and M. Bell, Esq., were elected Fellows of 

 the Society. 



The following communications were read : — 



1. Onthe Geology of luYciA. By Professor Edward Forbes, F.R.S., 

 and Lieut. T. A. B. Spratt, R.N., of H.M.S. Beacon. 



The district explored by the authors extends over two degrees of 

 longitude and one of latitude. It is chiefly occupied by a series of 

 alpine plains and mountain ridges, broken up by four great valleys. 



