Murray
Diagnosis: Shell subspherical, pear-shaped, seldom with flattened aboral surface. Peristome thick, ring-shaped, with 3 straight, divergent oral spines, with 8-10 large basal pores, with stout, partly branched thorns at their bases, partly fused with the peristome. Three (seldom four) straight, weakly spiny, aboral spines, somewhat bent only at the base, usually in an equatorial position, alternating with oral spines.
Length: 1.5-2.0 mm.