Definition: arthropod sensory structures consisting of special sensilla called the scolopidia, which are mechano-transducers and respond mainly to stretch or flexion. In insects, they consist of bundles of internal sensilla, each of which has a cap cell, an enveloping cell and one or more sense cells.
Definition: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.
Definition: A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.