Zoological Society. 37T 



can alone be determined by the acquisition of more complete speci- 

 mens of the animal than those at present known. 



In the construction of this table I have taken the proportions of 

 P. longirostris as the foundation, as it is the only species from which 

 I could get the measurements of all the bones of the wing from the 

 same animal ; but it must not be supposed that the restorations 

 effected in the table will be absolutely correct at all times in its appli- 

 cation, for we see that in P. longirostris the radius and first pha- 

 lange are equal, but in crassirostris and Bucklandi this is not the 

 case : the greatest discrepancy rests with crassirostris^ while Buck- 

 landi and brevirostris accord much more nearly with the proportions 

 of longirostris ; and if we may judge by the comparative difference 

 between those bones in longirostris on the one part, and Bucklandi 

 and crassirostris on the other, it may perhaps be fairly surmised that 

 the greater length of wing would be found to exist in the long-nosed 

 species, and consequently that Bucklandi will prove to belong to the 

 short-nosed ones ; and this also would seem to be indicated by what 

 remains of the cervical vertebrae in the original specimen in the Bri- 

 tish Museum. 



Prof. Owen, in treating of these animals in my late friend Mr. 

 Dixon's work *0n the Geology and Fossils of the Tertiary and Cre- 

 taceous Formations of Sussex,' has thought proper to re-name P. gi- 

 ganteus, and designate it P. conirostris, Owen. I certainly did not 

 lend my specimens to my late friend Mr. Dixon for the illustration 

 of his work, with a view of having the name which I had assigned to 

 this new and gigantic species subverted, and without in the slightest 

 degree being consulted on the subject. Nor can I concur with the 

 reasons given by Prof. Owen for thus re-naming it, as the name gi' 

 ganteus was not given, as stated by the learned Professor, ** because 

 certain bones of another and larger animal, of a different species, have 

 been erroneously referred to it;" but, in truth, from its being the 

 largest distinct species at that time known, exceeding P. Bucklandi 

 (or Macronyx) by two feet in the spread of its wings, and P. grandis 

 of Cuvier by above a foot. The beautiful specimen of radius and 

 ulna in the possession of Mrs. Smith, and subsequently figured in my 

 second paper, was at that time unknown to me, and the bone then in 

 the possession of the Earl of Enniskillen was claimed by the Professor 

 as that of a bird. I had therefore no other material than that in my 

 own possession on which to base my name of gi ganteus. 



If the learned Professor's reason for the proposed change of name 

 is to hold good, that of exclusive fitness in specific nomenclature, then 

 the one he proposes is also inappropriate, as it might be with equal 

 propriety given to either crassirostris or brevirostris ; or if specific 

 names, based on comparisons of size, are to be extinguished, and new 

 names given on the discovery of new species, there would be no end 

 of the confusion generated ; thus, as P. brevirostris is thicker in its 

 proportions than crassirostris, they would require to exchange names, 

 or the latter at least to be re-named ; tnedius would no longer be me- 

 divs, with the addition of our new species, huA grandis would no longer 

 be grand in comparison. Into what an unenviable state of confusion 

 Bhould we not plunge nomenclature if we were to adopt the practice 



