The following recently published paper is available upon request (see contact information below). Jefferson, T.A., D. Fertl, M. Michael, and T.D. Fagin. 2006. An unusual encounter with a mixed school of melon-headed whales (Peponocephala electra) and rough-toothed dolphins (Steno bredanensis) at Rota, Northern Mariana Islands. Micronesica 38:239-244. Little information is available on marine mammals occurring in the Northern Mariana Islands. On 4 July 2004, a group of about 500-700 melon-headed whales (Peponocephala electra) was observed and photographed at the surface and extensively underwater for several hours at the island of Rota in the Northern Mariana Islands. An unidentified number of rough-toothed dolphins (Steno bredanensis) also were part of the sighting. Bottom depths ranged from about 77 to 1,100 m over the course of the sighting. Regards, Dagmar Fertl Marine Mammal Biologist Geo-Marine, Inc. 2201 Avenue K, Suite A2 Plano, Texas 75074 USA 972-543-4137 FAX 972-543-4130 dfertl@geo-marine.com http://www.geo-marine.com