This genus is peculiar to America, where it is distributed over the whole of the southern and the western half of the northern continent, as well as in some of the West India Islands. There appears to be but one well-characterized species,[35] this one modified into representative races in the several geographical provinces over which it ranges. The species is terrestrial, inhabiting the abandoned burrows of Armadillos and Rodents. It is diurnal, possessing as much freedom of sight, hearing, and motion in the brightest sunlight, as any species of the _Falconidæ_. Species and Races. =S. cunicularia.= Colors umber-brown and ochraceous-white, the former predominating above, the latter prevailing below. Upper parts spotted with whitish; lower parts transversely barred with brown on the breast and sides, and sometimes on the abdomen. A white gular patch, and jugular collar, with a brown band between them. Legs, crissum, anal and femoral regions, always immaculate. =A.= Primaries with broad regular bars of ochraceous-white on both webs; primary coverts with large spots of the same. Brown markings of the lower parts irregularly transverse, and ragged. White spots on the upper parts nearly equal in extent to the brown. Wing, 6.15–6.40; tail, 2.90–3.60; culmen, .58–.62; tarsus, 1.50–1.80; middle toe, .65. _Hab._ Peru … var. _grallaria_.[36] Brown markings on the lower parts regularly transverse, and not ragged. White spots on the upper parts much less than the brown in extent. Wing, 7.00–7.50; tail, 3.30–4.00; culmen, .70; tarsus, 1.70–1.85; middle toe, .85. Outer tail-feathers and inner webs of primaries with the white much greater in amount than the brown (sometimes continuous along outer webs of the latter). _Hab._ Southern South America (Chile, Buenos Ayres, Paraguay, etc.) … var. _cunicularia_.[37] Wing, 6.40–7.00; tail, 3.00–3.30; culmen, .50–.60; tarsus, 1.50–1.70; middle toe, .80. Outer tail-feathers and inner webs of the primaries with the white less in extent than the brown (never continuous along outer webs of the primaries). _Hab._ Middle America, and Western Province of North America … var. _hypogæa_. =B.= Primaries without broad or regular bars of whitish on either web; primary coverts plain brown. Brown markings on the lower parts regularly transverse, and equal in extent to the white. White spots on the upper parts very small, reduced to mere specks on the dorsal region.