An i so pleura

Section of Gastropod a having the gills belonging to one side more or le suppre ed; or both gills may be absent, as in Heteropods, or placed externally, as in Nudibranches. There are two divisions, the Strep ton eur a and Enthyneura. These animals may be conceived as having had their dorsal portion rotated so as to stretch the original left side around to the right, thus pushing the right-side organs onto the left. The anus is thus brought forward to the neck, and the intestine forms a loop. The original left-side organs are usually aborted, i.e., not present on the new right side. An isopod a. See ISOPOD A.