Radials 3: centrals 3.
alternatus (1)
Radials 7 or 8: tubercles 40 to 50 mm. long.
longimamma (36).
Radials 10 to 12: tubercles 12 to 15 mm. long.
gummiferus (8).
++++ Radials numerous (16 to 60), capillary or bristle-like.
Radials 15 to 30, slender but rigid (bristly). acanthophlegmus(2), densispinus (4), bispinus (14), rhodanthus (26), sulphureospinus (27), palmeri (29), pringlei (32).
Radials 30 to 60 or more, mostly capillary. tetrancistrus* (22), capillaris (28), texanus* (31), spaerotrichus (33).
***** Central spines more than one and but one of them hooked.
Radials 10 to 15.
goodrichii* (16), setispinus (24).
Radials 15 to 30.
pondii (17), grahami* (19), bocasanus (20).
Radials 30 to 60.
tetrancistrus (22).