CRETACEOUS FORMATIONS. 85 



With respect to the long bone (T. XXXI, fig. 11), comparing it with that figured 

 in T, XXX, fig. 4, referred by me to Cimoliornis diomedeus, Mr. Bowerbank writes : — 



" Although the two specimens difi"er greatly in size, there is so strong a 

 resemblance between them in the form and angularity of the shaft, and in the com- 

 parative substance of the bony structure, as to render it exceedingly probable that 

 they belong to the same class of animals;" and he concludes by remarking that "if 

 the part of the head in my possession (see fig, 1), be supposed similar in its proportions 

 to that of Fterodadylus crassirostris, — and there appears but little difference in that 

 respect, — it would indicate an animal of comparatively enormous size. The length of 

 the head, from the tip of the nose to the basal extremity of the skull of P. crassirostris, 

 is about 4|- inches, while my specimen would be, as nearly as can be estimated, 9^ 

 inches. According to the restoration of the animal by Goldfuss, P. crassirostris 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 Pterodactyle, 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 

 Fterodactylus gig aniens ^^ (p. 8.) 



In a subsequent Memoir, read June 9th, 1847, and published in the 'Quarterly 

 Journal of the Geological Society,' February, 1848, Mr. Bowerbank gives figures of 

 the "bone-cells" from the jaw of a Pterodactgle (PL i, fig. 1), from the shaft of the 

 bone in question (ib., fig. 3), and from the femur of a recent Albatross (ib., fig. 13), in 

 corroboration of the required proof ; and he adds : — " Fortunately the two fine 

 specimens from the rich collection of Mrs. Smith, of Tonbridge Wells, represented 

 by fig. 1, PI. ii, in a great measure justify this conclusion, and in the bone a, which is 

 apparently the corresponding bone to the one represented by fig. 1 in Professor Owen's 

 Paper, the head is very nearly in a perfect state of preservation," (Op. cit, p. 5.) 

 Mr. Bowerbank, in his explanation of PI. ii, describes the two specimens above 

 mentioned, as : — " Fig. 1. Radius and ulna of PterodactgJus gigantetis, in the Cabinet of 

 Mrs. Smith, of Tunbridge Wells," (Tom. cit., p. 10.) He proceeds to state, "there 

 are two other similar bones imbedded side by side in the Collection of Mr. Charles, 

 of Maidstone, of still greater dimensions than those from the Cabinet of Mrs. Smith," 

 and he assigns his grounds for the conclusion, that " the animal to which such bones 

 belonged could, therefore, have scarcely measured less than fifteen or sixteen feet 

 from tip to tip of its expanded wings." These bones are represented in T. XXIX 

 of the present Monograph. 



The Committee of the British Association, for the Reform and Regulation of 

 Zoological Nomenclature, amongst other excellent rules, have determined, that : — 



" Names not clearly defined may be changed. Unless a species or group is 



