G2 ON THE GENUS PTILOPUS. 



Dr. Meyer remarks, in a letter to me : — 



" The Pigeons of the Eastern Archipelago belong to the choicest and 

 most interesting birds of the globe, in consequence of the variety which they 

 show as to gay colours and strange markings, and, from a scientific point of 

 views as to the materials which they afford to prove the variation of species 

 effected by isolation through insular conditions. 



" Among the very numerous species of Pigeons inhabiting the Papuan 

 archipelago, there are four nearly allied ones which present a special interest, 

 because, notwithstanding their being closely related to one another, they are 

 yet very distinct in marking and colour — the more obvious as they live in 

 close proximity ; they, indeed, form a small natural subgroup within the 

 large group of the Ptilopi. These four species are, enumerated chronolo- 

 gically in the order of their discovery, 



"1. Ptilopus rivolii, Prov., 



2. Ptilopus miquelii, Rosenb., 



3. Ptilopus speciosus, Rosenb., 

 4 Ptilopus bellus, Sclater. 



" P. rivolii has a wide range over a part of the Moluccas, the islands in 

 the west and north of New Guinea, and New Guinea itself. In the following 

 diagram of the geographical distribution we only consider its occurrence 

 on New Guinea and the islands of the Geelvink Bay : — 



"New Guinea. Mysore. Jobi. Mafoor. 

 "Ptilopus rivolii .... 1 — — 1 



Ptilopus miquelii .... — — 1 — 



Ptilopus speciosus ... — 1 — 1 



Ptilopus bellus .... 1 — — — 



" The females of the four species are green nearly all over, differ a little 

 in size, but are difficult to distinguish one from another. The males are all 

 green on their upper parts, P. speciosus and P. rivolii shading a little more into 

 bronze. Except P. speciosus, they all have a red patch on the head ; P. spe- 



