RUDOLOCULINA HOOPERI, A NEW MILIOLID WITH AN AGGLUTINATED OUTER SURFACE FROM THE NORTHEASTERN PACIFIC OCEAN

Rudoloculina hooperi , a new miliolid from Holocene and modern shelf sediments of the northeastern Pacific Ocean, is characterized by chambers that are quadrate in cross-section and by a test wall with embedded agglutinated grains, some of which consist of miliolid-type shell material (subparallel calcite laths). The agglutinated grains are either calcareous and low in magnesium (Mg/Ca ≤ 0.01) or silicic. Rudoloculina hooperi has previously been mistakenly reported from the same region as Quinqueloculina agglutinata Cushman. The morphologically similar genus Cycloforina has been reported mostly from warmer waters, suggesting that R . hooperi is near the northern limit of its range in the Gulf of Alaska.