Ten new species of Mollusca are described from Kaiatan (Upper Eocene) beds at McCullough's Bridge, South Canterbury, and Lome, North Otago. These include the first New Zealand records ofPseudomalaxisandColubraria. Species ofCondylocardia,Pareora,Opimilda,Mathildona,Fimbriatella, andCheileaare also described, and a brief review of New Zealand species of the Mathildidae is included.Notogrammatodon, a new subgenus ofPseudogrammatodon(Arcidae), is proposed, withP. (Notogrammatodon) inexpectalusn. sp. as type.Eosirius(with typeE. admeteformisn. sp.) is proposed as a new genus of the Trichotropidae. Both these groups appear to have representatives in the Australian Tertiary.