Three species of Pectinidae are now known from three separate fossiliferous deposits in the McMurdo Sound area of Antarctica. Only one of these,Adamussium colbecki(Smith), is known to be living at the present time. This species is also found in the Taylor Formation, the youngest formation in the area.Chlamys(Zygochlamys)anderssoni(Hennig) occurs in the Scallop Hill formation, which is considered older than the Taylor Formation because it has been glaciated, whereas the Taylor Formation has not. The third is a new species,Chlamys(Zygochlamys)tuftsensis, from the deposit of the Pecten Glaciation located far up Wright Valley. Because of the unconsolidated nature of this deposit it may be younger than the consolidated Scallop Hill Formation. It is definitely older than the Taylor Formation.