extends down to connect with the water table (extending further down in summer and may rise again during winter) and type 3 is a burrowing system which relies heavily on run off. The type 3 burrowing system is characteristic of the Engaeus genus, classifying them as the most terrestrial genus of all the burrowing crayfish.The burrowing crayfish typically occupy environments which are wet, muddy or peaty environments such as wetlands, swamps, floodplains of small streams, sedge-land or in rainforests. As the Engaeus genus dispersal using water ways is limited due to their terrestrial nature, local speciation rates may be high. A characteristic feature of the genus, Engaeus, is that the entrance of their burrows typically has a ‘chimney’ structure constructed out of balls of mud. The structure can be only a few mud balls or can be as big as 40cm in height, although this behaviour is seen in the entire genus, it is unknown why the burrowing crayfish do this. Additionally, during hot periods, the crayfish will plug the chimney, potentially to retain as much moisture as possible in their tunnelling systems. Distribution The genus of Engaeus is typically found in the north and west of Tasmania but can also be observed occurring in the north-east. This genus has geographical territories that differ in size with some species having extensive areas of distribution while others only have very limited areas. Most species border each other, creating a distribution pattern similar to a puzzle. However, it is not common for the distribution of the species in this genus to overlap, though it does occur in rare circumstances. Doran (2000) states that there are four species of conservation concern due to a decrease in their distribution, these species include E. orramakunna (the Mt. Arthur burrowing crayfish), E. spinicaudatus (the Scottsdale burrowing crayfish), E. yabbimunna (the Burnie burrowing crayfish) and E. martigener (the Furneaux burrowing crayfish) Threats Threats for the Engaeus genus, especially E. orramakunna - the Mt. Arthur burrowing crayfish, E. spinicaudatus - the Scottsdale burrowing crayfish, E. yabbimunna - the Burnie burrowing crayfish and E. martigener - the Furneaux burrowing crayfish, due to their threatened status include: Agricultural processes including grazing of livestock which results in compacted or disturbed soil, construction of dams, clearance of native vegetation and ploughing. Forestry activities such as the creation of plantations through the clearing and burning of natural vegetation, which causes significant disturbance to