J jacket cells (MESO: Orthonectida) The ciliated somatoderm; the number of body rings and their arrangement is of taxonomic importance. jaculatory duct A region of the vas deferens through which sperm is emitted. see ejaculatory duct. | J jacket cells MESO Orthonectida The ciliated somatoderm the number of body rings and their arrangement is of taxonomic importance. jaculatory duct A region of the vas deferens through which sperm is emitted. see ejaculatory duct. Johnston s organ ARTHRO Insecta A chordotonal organ located in the second segment of the antenna and functioning in sound perception flight speed indicator or water wave perception. joint n. L. jungere to join An articulation of two successive segments or parts. Jonstonian organ see Johnston s organ jordanon see microspecies Jordan s organ see chaetosemata jubate a. L. jubatus crested Fringed with long mane-like hairs. juga pl. of jugum jugal angle MOLL Polyplacophora The angle formed by the two halves of an intermediate valve. jugal area tract MOLL Polyplacophora The upper surface of a valve immediately adjacent to the jugum sometimes sculptured differently from the rest of the surface dorsal area. jugal bristles ARTHRO Insecta Bristles located on the edge of the jugal lobe. jugal coverage see valve coverage jugal fold see plica jugalis jugal lobe ARTHRO Insecta A lobe at the base of the fore wing that makes contact with the hind wing to prevent the wings from moving out of phase. jugal muscles MOLL Thick longitudinal muscles at the base of Online Dictionary of Invertebrate Zoology 493 the radular mass. jugal region 1. ARTHRO Crustacea In Decapoda the anterolateral part on the ventral surface located on opposite sides of the buccal cavity pterygostomial region. 2. AR-THRO Insecta The posterior basal lobe or area of a wing demarcated from the vannal region by the jugal fold plica jugalis . jugal sinus MOLL Polyplacophora A depression between the sutural laminae of chitins. jugal tract MOLL Polyplacophora The tegmentum surface adjacent to the jugum. jugo-frenate wing coupling ARTHRO Insecta Lepidoptera wing coupling where the jugum is folded under the fore wings and holds the frenular bristles. jugular a. L. jugulum collar bone throat Of .
