Bill shorter than the head, stout, straight, broader at the base than high ; nostrils elongate, in a shallow groove-like depression ; eyes very large; forehead high ; wing long, pointed, 2nd primary as a rule longest; tail of 12 feathers, of moderate length, slightly, rounded; only 3 toes ; nail of middle toe broad, dilated on the inner side.
This genus contains eight species found nearly throughout the temperate and tropical regions of the Old World and in Central and South America. A single species is Indian.
* Pluvianus is an exception, but it is not Indian. The figures on the opposite page are intended to show the difference between holorhinal and schizorhinal structure. In the former the external binder border of the osseous nares is simple and usually rounded ; in the latter the orifice is prolonged posteriorly, and terminates in a narrow fissure between the processes of the nasal bones. This fissure varies in length and direction in different birds.