Head shallowly convex, vaguely longitudinally impressed at median; punctation dense, punctures separated by <0.3X own diameter, umbilicate
. Frontal margin narrowly shelf-like, slightly reflexed, obtusely carinate, carina shallowly sinuate in anterior view.
Clypeus with short umbilicate setae, punctures uniformly distributed, separated by a distance much greater than diameter of one puncture; clypeal suture deep.
2) with anterior angles acute, posterior angles acute but the point rounded; anterior margin broad, posterior margin bisinuate; lateral margins thick and raised, feebly expanded laterally, without punctures on dorsal surface, with a row of short, umbilicate setae on inner surface; pronotum widest at mid point; disc flattened, higher than lateral margins, with longitudinal, parallel, thick wrinkles, 20 or more on the midlength of pronotum occupying all the surface, reaching anterior and posterior margin of pronotum (Fig.
Promenetus umbilicatellus (Cockerell, 1887) umbilicate
growth form is also common throughout the Antarctic, and includes all the species of Umbilicaria.
Notes: Natalina beyrichi is unlikely to be confused with any other species on account of its depressed, widely umbilicate
shell and coastal distribution in the north-eastern E.
series of marginal setae consisting of 6 subhumeral, 3 intercalar, 4 subapical setae and one apical seta.