valve

Lateral part of divided carapace commonly joined to opposite part by hingement along dorsal mid-line (e.g., Ostracoda, Conchostraca, Leptostraca) [Moore and McCormick, 1969].

Lateral part of divided carapace, commonly joined to opposite part by hingement along dorsal midline; also any one of opercular elements in sessile Cirripedia [McLaughlin, 1980].

(Order Cladocera):

Term applied to each half of carapace, one half (valve) covering each side of trunk [Stachowitsch, 1992].

(Order Diplostraca):

One of two shell elements comprising carapace. Covering left and right sides of body and joined together (or continuous) dorsally along hinge line. Consists of several layers and is variously ornamented on exterior. (See also carapace) [Stachowitsch, 1992].

(Order Isopoda):

Term applied to uropods covering branchial chamber in certain isopods [Stachowitsch, 1992].

(Subclass Cirripedia):

Opercular valve [Stachowitsch, 1992].

(Class Ostracoda):

Aortic valve, hepatic valve [Stachowitsch, 1992].

(Class Ostracoda):

One of two shell-like elements covering left and right sides of body (therefore left valve, right valve). Valves joined to each other dorsally by hinge and may bear complex system of ridges and grooves around margin that inter-fit when carapace is closed. Consists of inner and outer lamellae. (equal, subequal, unequal; amplete, postplete, preplete; lateral outline: circular, elliptical, elongate, ovate, quadrate, reniform; smooth, ornamented: e.g., alate, bilobate, bisulcate, bullate, caperate, carinate, celate, clavate, costate, foveolate, granuloreticulate, granulose, lobate, papillate, pitted, punctate, quadrilobate, reticulate, setose, spinose, striate, sulcate, trilobate, trisulcate, tuberculate, unilobate, unisulcate, verrucose) (see also valve sculpture) [Stachowitsch, 1992].

(Class Ostracoda):

Right or left half of bivalved ostracode carapace (sometimes erroneously referred to as "shell") [Cohen, Peterson, and Maddocks, in press].