562 SYSTEM A TIC SYNOPSIS. — COL UMBuE — PERISTEUM. 
seems best to draw the liue, if one must be drawn, so as to include the Pterocletes in Columhcey 
and leave the Cracidce and Megapodidce with GallincB. The Sand-grouse (better Sand-pigeons)^ 
or Ptei'odetes, represent the inosculation of the two series. They are terrestrial Columbines, 
modified for a grouse-like life ; the digestive system is fowl-like (coeca several inches long, etc.); 
but the pterylosis, the sternum and humerus, the cranial and many other characters, are pigeon- 
like. The only alternative to reference of Pterocletes to the Columbine series is their elevation 
to independent ordinal rank, as proposed by Huxley. 
The ColumbcB, as above indicated, are intended to be made conformable to Huxley's Periste- 
romophae plus Pterocletes. Assuming the imperfectly-known extinct Dodo, Didus ineptus, to 
have been a modified Columbine, and considering the Pterocletes to represent a rasorial modi- 
fication of the Columbine series, the Order Columhce may be separated into three groups, or 
suborders, Didi, Pterocletes, and Perister^, the first two certainly, the last probably, of 
a single family. The Pei'isterce alone are American. 
9. Suborder PERISTEE^ : True Columbine Birds. 
(Equivalent to the PeristeromorphcE of Huxley ; the Gemitores of Macgillivray, or 
Columhce proper of most authors ; the Gijrantes of Bonaparte, plus Didunculus; Columhce of 
Garrod minus Pterocletes; Pullastrce of Liljeborg minus Cracidce and Megapodidce.) Skull 
schizognathous, schizorhinal ; basipterygoids prominent ; angle of mandible not produced ; 
rostrum externally as above said. Sternum doubled-notched or notched and fenestrate, on 
each side ; pectoral crest of humerus salient, acute. Carotids two. Syringeal muscles one 
pair. Coeca coli small or wanting ; gizzard muscular ; crop developed ; gall-bladder generally 
absent. Fourth glutaeal muscle undeveloped ; second pectoral specially inserted ; ambiens 
normally present, or wanting. Oil-gland nude, small, or wanting. Plumage without after- 
shafts. Feet insessorial; hallux normally insistent; tarsus normally scutellate. Rectrices 
normally 12 or 14. (Rasorial tendency in more rectrices, hallux up, and tarsus reticulate.) 
Altricial ; psilopaedic ; monogamous ; eggs few. One family f 
34. Family COLUMBID^ : Pigeons. 
The family is here taken to be co-extensive with the 
suborder as defined. With one exception (Starnoenas 
cyanocephala) , all our species will be immediately recog- 
nized by their likeness to the familiar inmates of the 
dove-cot. One seemingly trivial circumstance is so con- 
stant as to become a good clue to these birds : the frontal 
feathers do not form antiae by extension on either side of 
the culmeu, but sweep across the base of the bill with a 
strongly convex outline projected on the culmen, thence 
rapidly retreating to the commissural point. The plunmle- 
less plumage is generally compact, with thickened, spongy 
rhachis, the insertion of wliich will seem loose to one who 
skins a bird of this fiimily. The head is remarkably 
small ; the neck moderate ; the body full, especially in the 
pectoral region. The wings are strong, generally length- 
ened and pointed, conferring a rapid, powerful, whistling 
flight ; the peculiar aerial evolutions that these birds are 
wont to perform have furnished a synonym for the family, 
Gyrantes. The tail varies in shape, from square to grad- 
uate, but is never forked; as a rule there are 12 rectrices, frequently increased to li, rarely to 
Fig. 389. — European Ring Dove (Cb- 
lumba palumbus). (From Dixou.) 
