corbel - a block of stone, elaborately carved, projecting from a wall and sometimes supporting a load such as the beams of a roof, floor or vault, or sometimes used for decorative effect only.

Corbels in the rotunda of the Connecticut state capitol.

egg & dart - Classical ornamental design that forms a course of alternating oval shapes and arrows.

Egg & dart pattern in a coffered ceiling in the Vermont capitol.

guilloche - an ornamental border formed of two or more interlaced bands around a series of circular voids.

Fluted columns with guilloche in the Texas state capitol.

rotunda - any building or a room within a building with a circular ground plan. In state capitols, these are often covered with a dome.

Virginia’s capitol has a square rotunda with only an inner dome.

volute - A spiral scroll-like ornament commonly found on Ionic, Composite or Corinthian columns.

Volute on a column in the Utah state capitol.

pilaster - a rectangular column projecting slightly from a wall.

Pilasters in the rotunda of the Wisconsin capitol.

pediment - a low triangular gable in classical architecture, surrounded by a cornice.

Pediment over the front portico of the Oklahoma capitol.

balustrade - handrail supported by balusters; any of the small posts that support the upper rail of a railing, as in a staircase or porch rail.

Balustrade on the grounds of the Missouri capitol.

portico - a porch leading to the entrance of a building.

Night photo of the portico in front of the Vermont capitol.

festoon - a carved ornament in the form of a garland of fruit and flowers, tied with ribbons and suspended at both ends in a loop.

Festooned oculus window on the Indiana capitol dome.

capital - The head or top of a column or pilaster.

Capital in the Massachusetts state house.

anthemion - Greek ornament of alternating palmettes and lotus motifs or two types of palmettes (one open, one closed).

Anthemion in gold on green in the Pennsylvania capitol.

cornice – the molded and projecting horizontal member that crowns an architectural composition.

modillion - An ornamental bracket, usually in the form of a scroll with acanthus leaf, supporting the cornice.

Cornice decorated by modillions & rosettes surrounds a pediment on the Iowa capitol.

bracket - a small projection, usually decorated, that supports or appears to support a projecting eaves or lintel.

Brackets on pilasters in the entry of the Delaware legislative hall.

pendentive - a trapezoidal section of vaulting between the rim of a dome and each adjacent pair of the arches that support it.

Decorated pendentive in the rotunda of the Utah capitol.

oculus - a round window; a round opening at the top of a dome.

Oculus at the top if the Oklahoma rotunda dome.

wave - or running dog - a Greek ornamental design like waves.

A running wave pattern on the New Hampshire capitol.

swastika - an equilateral cross with its arms bent at right angles, in either right-facing or left-facing form, or both in a running design.

A running swastika pattern in the Wisconsin capitol.

ancone - A decorative bracket in the form of a vertical scroll that supports a cornice or entablature over a door or window.

Ancone decorated with female bust on the West Virginia capitol.

atrium (plural atria) - A large rectangular interior space, usually several stories tall, connecting parts of a building. Atria usually have skylights or windows at the top to bring light in.

The eastern atrium of the Georgia state capitol.

pendant  - a bulbous, knob-like ornament which hangs downward.

Pendant on the ceiling of the Texas House of Representatives.