Haeckel
Diagnosis: Lattice shell generally spindle-shaped, with both poles rounded at ends or with one end more pointed than the other, with triangular mesh openings. Tangential bars considerably stouter on rounded pole. Radial tubes about as long as tangential bars. Distal ends of tubes with whorl of 3-6 branches. Terminal branches of distal whorl somewhat shorter than those of inner whorl. Branches forked, with spiny terminal pads. Proximal radial tubes sometimes with one or a few lateral thorns.
Length: 3-10 mm.