Borgert
Diagnosis: Spheroidal lattice shell with subregular, generally pentagonal or hexagonal mesh openings. Radial tubes 2 to 5 times length of tangential bars. Proximal half to two thirds of radial tubes with single or paired, irregularly distributed, curved, lateral thorns. Distal thorns usually in 1 or 2 loose whorls, 3 teeth in terminal position. Sometimes one or a few thin, straight, centrifugal needles on tangential bars.
Diameter: 1.4-1.8 mm.