512 MR. D. G. ELLIOT ON THE GENUS PTILOPUS. [May 7, 



any reasons (after a careful examination of the species separated 

 generically by him) for accepting his divisions. The species named 

 by Schlegel Pt. insolitus has been made the type of a genus, 

 OEdirhinus, by Cabanis and Reichenow. The same peculiarity ex- 

 hibited by this bird — a bony protuberance upon the base of the 

 culmen — is also found in certain members of the genus Carpophaga ; 

 and I see no more reason for separating Pt. insolitus from the 

 other members of this genus than exists for placing these Garpophagce 

 in a new generic division. The term Megaloprepia, instituted by 

 Reichenbach for certain birds of this group, was so oddly selected, at 

 least in one instance (Pt. perlatus) that a doubt arises in my mind if 

 the author had ever had an opportunity of examining specimens. 

 No characters were given by him which were not also to be found in 

 other species of Ptilopus ; and although the term has been employed 

 by some authors, it seems to me to be entirely unnecessary ; for it is 

 impossible to designate in a large series ofPtilopi where the genus (?) 

 should commence, as the species graduate into one another from the 

 smallest to the largest. 



Prof. G-arrod, in the 'Proceedings' of this Society for 1874, in 

 his paper on the "Anatomy of the Columbse," states that the 

 members of the genus Ptilopus possess a form of gizzard such as is 

 not found in any other bird, and gives figures exhibiting its peculi- 

 arities as compared with Treron. If this is ascertained to be a con- 

 stant formation in all the species of Ptilopus, it may well be deemed 

 of sufficient importance to constitute a generic character ; but, unfor- 

 tunately, as yet, it cannot be said to be proven ; for out of the seventy- 

 one species considered in this memoir as belonging to Ptilopus, Prof. 

 Garrod has only been able to dissect three, a number too insignifi- 

 cant for it to be decided that all the members of the genus have the 

 same formation. The Carpophagce do not possess a similar gizzard ; 

 yet certain species of Ptilopus, viz. Pt. magnificus with its races assi- 

 milis and puella, and Pt. gularis, in their outward form resemble 

 certain species of Carpophaga ; and it is possible that in some of these 

 at least a modified form of gizzard may be found to exist. It will be 

 interesting to learn if such be the case, or if really the species of 

 Ptilopus are separated from all other Pigeons by an abrupt alteration 

 in the gizzard's shape, one not approached by that of any other bird. 

 A large number of species must be first examined before this can be 

 definitively ascertained. 



The following are the principal generic terms which have been 

 proposed for these birds. 



Type. 

 (1825) Ptilonopus, err. Swains. Zool. Journ. vol. i. p. 473 Pt. regince. 

 (1841) Ptilopus, corr. Strickl. Ann. Nat. Hist. vii. p. 36. 

 (1854) Leucotreron, Bon. Compt. Bend. vol. xxyix. p. 876 Pt. ductus. 



(1854) Cyanotreron, Bon. torn. cit. p. 878 Pt. monachus. 



(1854) Bhamphicidus, Bon. ibid Pt. occipitalis. 



(1854) Omeotreron, Bon. ibid Pt. occipitalis. 



(1854) Knrut.reron, Bon. ibid Pt. purpuratus. 



(1854) Chrysana, Bon. ibid Pt. luteonrcns. 



(1854) Thouarsitreron, Bon. torn. cit. p. 876 Pt..dupetit-thouarsii. 



(1854) Lamprotreron, Bon. ibid Pt. superba. 



