Reference

Theodor Ole Jensen Mortensen (1948): Report on the... 3. The Echinoneidae, Echinolampadidae, Clypeastridae, Arachnoididae, Laganidae, Fibulariidae, Urechinidae, Echinocorythidae, Placostomatidae, Micrasteridae, and Spatangidae – United States National Museum – 100/6/4.