708 SYSTEMATIC SYNOPSIS.— COLUMBjE — PERISTERjE. 



Guinea is the centre, where more than a fourth of the species occur. Mr. Wallace accounts for 

 this by the absence of fruit-eating forest mammals, sucli as monkeys and squirrels ; and finds 

 in the converse the reason why Pigeons are so scarce in the Amazon valley, and there chiefly 

 represented by species feeding much on the ground and breeding in the bushes lower than 

 monkeys habitually descend. " In the Malay countries, also, there are no great families of 

 fruit-eating Passeres, and their place seems to be taken by the true Fruit-Pigeons, which, un- 

 checked by rivals or enemies, often form with the Psittaci the prominent and characteristic 

 features of the Avifauna." {Newton.) 



There are several prominent groups of Pigeons ; but authors are far from agreed upon 

 subdivisions of the family. It is not probable that Garrod's tliree subfamilies, based upon 

 characters of ambiens, coeca, gall-bladder, and oil-gland, will stand without great modification, 

 and I cannot adopt his arrangement. Sclater divided the suborder Columhce as above defined 

 into two families, ColnmhidcB and CarpophariidcB, to which he afterward added Gowidce, and 

 probably Didunculidce. Bonaparte made five families, Didunculid(e, Treronidce, Columbidce, 

 Caloenadidce, and Gouridce (three of them upon single genera), with 12 subfamilies. This is a 

 pretty good scheme, the main features of which are reflected in the classification adopted by the 

 latest monographer. Thus, Salvadori has also five families, as follows : 1. Treronid^, with 

 subfamilies Treronina;, Ptilopodince, and Cariwpliagince. 2. ColumbidvE, with subfamilies 

 Colmnbinoe, Macropyfiiincc, and Ectopistincc. 3. Peristerid^, with subfamilies Zenaidina, 

 Turturince, Geopeliince, Peristerincc, Phahince, Geotrygonina;, and Ccdocnadincc. 4. Gouridje, 

 one genus. 5. Didunculid^, one genus. From this number of families I would not dissent, 

 but propose to raise Caloenadince to the rank of a family, and unite Salvadori's Peristeridce with 

 his Columhidce, thus reverting to the Bonapartian evaluation of the five major groups, whose 

 characters may be thus indicated : — 



1. The extraordinary Tooth-billed Pigeon of the Samoan Islands, Diduncidus striyirostris, 

 alone represents a family, with its stout, compressed, hooked, and toothed beak, and many 

 other peculiarities. The length of intestine is excessive, being 7 feet instead of about 2, as 

 usual in Columbidce. Ambiens present; oil-gland and gall-bladder absent; 14 tail-feathers. 



(DlDUNCULID^E.) 



2. The singular genus Goura, with six Papuan species like G. coronata, is outwardly dis- 

 tinguished by its immense umbrella-like crest of feathers whose webs are decomposed, and 

 possesses anatomical peculiarities which entitle it to stand alone as type of another family. 

 Tarsi entirely reticulate ; 16 rectrices ; coeca, gall-bladder, oil-gland, * and ambiens wanting ; 

 intestines 4-5 feet long ; the pterylosis is galline rather than columbine, and the period of incu- 

 bation is greatly protracted (4 weeks) (Gourid.e.) 



3. The single Malaysian genus Ccdcenas, with two species, C. nicobarica and C pele- 

 wensis, has a very tumid bill, and acuminate, lengthened, pendulous feathers of neck like those 

 of the domestic cock and hen ; 12 rectrices, as in ordinary Pigeons, and the anatomy is con- 

 formable to a usual type, except that the lining of the gizzard is ossified. (Calcenadid^.) 



4. The Old World genera Treron, Ptilopus, and Carpophaga are leading representatives 

 of a large group of fruit-eating, arboricole species, with a short, stout beak, short, soft, broad- 

 soled, and extensively feathered feet, normally 14 rectrices (very exceptionally 12 or 16), and 

 soft, lustreless plumage, of which green is the characteristic color; " 54 species are confined 

 to the Austro-Malayan, while 28 inhabit the Indo-Malayan, subregion ; in India 14, and 

 in Africa a species are found ; 30 inhabit the Pacific Islands, and 8 occur in Australia or 

 New Zealand, while New Guinea has 14 species'' {Wallace). (Family Treronid^, di- 

 vided by Salvadori into : Treronince, 7 genera, 43 species ; Ptilopodin^, 5 genera (one 

 of them, Ptilopus, M-ith 12 subgenera), 88 living species ; and Carpophagincs, 7 genera (one 



* Beddard has, p. 314, "with " these organs, by evident slip for "without," as he marks them all absent in his 

 table on p. 312. 



