Figure 7. Confocal projections of phalloidin-labelled larvae of Pantinonemertes californiensis showing surface cell outlines in the early invagination stage (A), early rudiment stage (B), late rudiment stage, which is contemporary with shedding of the larval epidermis (C), and the vermicular stage (D, E). At 15–16◦C these stages correspond to 23.5 hours (A), 2 days (B), 3 days (C) and 4 days (D, E) of development; ventral view, apical up. (E) An 11.5-µm sub-stack from the same stack as (D) shows the cell outlines without the interference of body wall muscles. (A) Mounted in Vectashield and scanned using 60 × Oil lens (NA 1.4); (B–E) mounted in phosphate-buffered saline and scanned using 60 × water lens (NA 1.2). Apical plate (ap), proboscis (pb), stomodeum (st), anterior invaginations (ai), remnants of posterior invaginations (pi∗), muscles (ms). Asterisks mark several provisional larval epidermis cells.