ovisac

(Order Notostraca):

In female, brood chamber for eggs on each appendage of last (11^th) thoracic segments; chamber formed by exopod, with epipod serving as lid [Stachowitsch, 1992].

(Order Anostraca):

In female, unpaired, sac-like structure projecting from ventral surface of first and second abdominal somites (= genital somite). Contains cement glands and serves as brood chamber for eggs. (cylindrical, subglobular). (Syn. egg sac) [Stachowitsch, 1992].

(Class Cephalocarida):

Sac-like structure attached to rudimentary appendage ("genital appendage") of ninth postcephalic segment (= first abdominal segment). Serves as brood chamber for egg. (single, paired) [Stachowitsch, 1992].

(Order Tanaidacea):

In female of certain tanaidaceans, term applied to brood chamber formed by single pair of oostegites of fifth pereopod pair. See: marsupium [Stachowitsch, 1992].

(Subclass Cirripedia):

Region of mantle cavity in which eggs are brooded. (See also brood chamber) [Stachowitsch, 1992].

(Class Ostracoda):

In female, sac-like structure projecting from ventral surface of first abdominal segment (genital somite). Secreted by oviduct; serves as brood chamber for extruded, fertilized eggs. (single, paired). (Syn. egg sac) [Stachowitsch, 1992].

(Order Euphausiacea):

In certain female euphausiaceans, sac-like structure associated with posterior thoracopods and serving to brood eggs. (single, double, fused) [Stachowitsch, 1992].