Parisotoma notabilis (formerly Isotoma notabilis) is a very common and widespread species which is extracted in large numbers from most samples of soil in Tullgren funnels. Typically < 1.1 mm in length, although larger individuals are sometimes found in caves. The numerous ventral manubrial setae (Fig. 2), square black eye patch (Figs. 1,3) and serrated setae on the abdomen (Fig. 4) are distinctive. The mucro has three teeth, although careful orientation is needed to see these (Figs. 5 and 6). Since Parisotoma notabilis is probably present in every hectad in UK/Eire, the distribution of dots on the adjacent map is a good indication of the level of Collembola recording in particular regions; note in particular the thinness in Scotland and the south west.