1874.] ANATOMY OF THE COLTIMB*. 251 



II. The presence or absence of the oil-gland in the genera of the 



Columbae. 



The oil-gland is present in most of the Pigeons ; it is very small 

 in the genus Ptilonopus. It need hardly be remarked that, when 

 present, it is never tufted. 



The oil-gland is present in all the specimens examined by me of 



Calamas, Metriopelia, 



Carpopkaga, Ocyphaps, 



Chalcopelia, Phaps, 



Chalcophaps, Phlogcenas, 



Chamcepelia, Ptilonopus (? in P. melano- 



Columba, cephalus), 



Ectopistes, Pterocles, 



Geopelia, Turtur, 



Leptoptila, Tympanistria, 



Leucosarcia, Zenaida, 



Lopkolcemus, Zenaidura. 



Macropygia, 



The oil-gland is absent in all my specimens of 



Didunculus, Starncenas, 



Goura, Treron. 



III. The presence or absence of cceca to the intestine in the genera 



of the Columbae. 



My dissections lead to the result that the intestinal caeca are 

 absent in more genera of Pigeons than they are present in, being found 

 in only 7 out of 26. When present they never exceed a quarter of 

 an inch in length (except in the Pteroclidae), and are frequently not 

 half that size. In Turtur they are generally shorter than in 

 Columba. 



Caeca are present in 



Columba, Pterocles, 



Ectopistes, Starnosnas, 



Macropygia, Turtur. 

 Phlogcenas, 



Caeca are absent in 



Caloenas, Lopholcemus, 



Carpophaga, Metriopelia, 



Chalcopelia, Ocyphaps, 



Chalcophaps, Phaps, 



Chamapelia, Ptilonopus, 



Didunculus, Treron, 



Geopelia, Tympanistria, 



Goura, Zenaida, 



Leptoptila, Zenaidura. 



Leucosarcia, 



17* 



