egg and dart

noun1

1. •
   An ornamental device adorning the fundamental quarter-round, convex ovolo profile of moulding, consisting of alternating details on the face of the ovolo: typically an egg-shaped object alternating with a V-shaped element such as an arrow, anchor, or dart.

   • There were various armchairs […] beneath a high ceiling with plaster egg and dart cornices, brocaded curtains and a blazing fire of sycamore logs. — 2019