Gills are specialised organs containing filaments, which further divide into lamellae. Gills are specialized organs containing filaments, which further divide into lamellae. Perthite is either microcline or orthoclase with thin lamellae of exsolved albite. Each gill has a main axis with many lateral filaments or lamellae that are vascularized. These extensions are in the form of vesicles, tubules, and lamellae. The channels are formed by concentric layers called lamellae. Thus each gill bears hundreds of thin membranous lamellae arranged like pages in a book. The gill is composed of branchial ganglia and a series of folded lamellae. The individual lamellae of the gills lie on either side of the septum. The crowded white lamellae (gills) are free. It is similar to plywood but with distinctively thicker laminations (or lamellae). The ridges themselves consist of individual lamellae (6-12) which overlap like shingles on a roof. The nymphs are usually green with browner wing buds and lamellae. The instrument consists of several iron lamellae, fixed to a rectangular wooden soundbox. Lamellophones are instruments which have little tines, or "lamellae", which are played by plucking.