Two gem-set novelty brooches

Two gem-set novelty brooches
The first modelled as a conch shell, with naturalistic engraving and single-cut diamond border, Portuguese marks, 3.5 cm wide; the second modelled as a stylised jellyfish, with central single-cut diamond domed cluster, garnet surround and diamond accents on the tentacles, French marks, 5.3 cm long