Final answer:
The ornamental motif described as Egg & Tongue is correctly identified as 'a. Egg & dart.'
Step-by-step explanation:
An ornamental motif for enriching an ovolo or echinus consisting of a closely set, alternating series of oval and pointed forms, known as Egg & Tongue, is represented by a. Egg & dart. This motif is a classic architectural detail, often found in Greek and Roman buildings as well as in neo-classical architecture. It is commonly seen as a decorative border along the edge of a building element called an entablature, which is situated above the columns. The egg & dart pattern is created by alternating an egg-shaped element with a dart or arrow-shaped element, and it can be found in cornices, friezes and moldings.
The motif can be observed in historical architecture such as the Maison Carrée, where egg-and-dart trim is present above the architrave and complements other design elements like the acanthus leaf motif on Corinthian capitals. Ornamentation in architecture often carries symbolic meanings, and the egg & dart may symbolize life and death, combining the organic shape of the egg with the pointed, spear-like dart.
Other examples of ornamental design in architecture include volutes which are spiral designs that resemble scrolls or cinnamon rolls, notably featured on Ionic capitals, as well as rosettes, anthemions, and the intricate designs of cloisonné and arabesque patterns. Each of these different ornaments contributes to the rich visual language of architecture and design.