FIG. 1.

Locations of O. crassitunicatus sampling sites on the Peru margin. The worms used in this study were collected at station A at a depth of 359 m and at station B at a depth of 270 m. The two stations are separated from each other by 385 km. Station L is a site sampled by Lisa Levin in 1998 at a depth of 305 m (12°22.7′S, 77°29.1′W); this station was called station A by Levin et al. in reference 30 and station 1 by Levin et al. in reference 31. Specimens from the Levin cruise were used by Giere and Krieger (23) for their ultrastructural studies of O. crassitunicatus.