Ozopore the Sclerosomatidae secrete short-chain acyclic ketones and alcohols, and the Phalangiidae, naphthoquinones. In millipedes, ozopores are repeated serially on body segments, and usually situated laterally. Exceptions are members of the order Glomerida, which have ozopores located dorsally. Some members of the order Julida have especially prominent ozadenes. Ozopore An ozopore is the opening of a defensive gland present in some arthropods, notably in millipedes of the order Polydesmida and in harvestmen, the eight-legged arachnids also known as "daddy long-legs". The glands themselves are known as ozadenes, also called "scent glands", "repugnatorial glands", "odoriferous glands" or "stink glands" by various authors.
Sea spider insects or crustaceans. This is in dispute, however, as genetic evidence suggests they may be the sister group to all other living arthropods. Sea spiders have long legs in contrast to a small body size. The number of walking legs is usually eight (four pairs), but species with five and six pairs exist. Because of their small size and thin body and legs, no respiratory system is necessary, with gases moving by diffusion. A proboscis allows them to suck nutrients from soft-bodied invertebrates, and their digestive tract has diverticula extending into the legs. Certain Pycnogonids are so small that each