Defn: Having equal pressure. Isopiestic lines, lines showing, in a diagram, the relations of temperature and volume, when the elastic force is constant; — called also isobars.
ISOPLEURA
I`so*pleu"ra, n. pl. Etym: [NL. See Iso-, and Pleura.] (Zoöl.)
Defn: A subclass of Gastropoda, in which the body is symmetrical, the right and left sides being equal.
Note: The intestine terminates at the posterior end of the body, and the gills and circulatory and reproductive organs are paired. It includes the chitons (Polyplacophora), together with Neomenia and Chætoderma, which are wormlike forms without a shell.
ISOPOD
I"so*pod, a. (Zoöl.)
Defn: Having the legs similar in structure; belonging to the Isopoda.
— n.
Defn: One of the Isopoda.
ISOPODA
I*sop"o*da, n. pl. Etym: [NL. See Iso-, and -poda.] (Zoöl.)
Defn: An order of sessile-eyed Crustacea, usually having seven pairs of legs, which are all similar in structure.
Note: The body is usually depressed, with the abdominal segments short, and often consolidated in part. The branchiæ are on the abdominal appendages. The group includes the terrestrial pill bugs and sow bugs, with numerous marine forms. See Arthrostrata, Gribble.