Haeckel
Diagnosis: Spherical shell with hemispherical valves. Galea arched and aborally concave. Nasal opening with cleft. Four primary radial tubes bifurcate 6 to 9 times at acute angles, branches smooth and straight or slightly curved, very small knobs at end of each terminal branch, each with 3-4 short recurved teeth.
Diameter: 1.8-2.5 mm.