The Echinoid Directory

Family Phormosomatidae Mortensen, 1934, p.

Diagnosis	Echinothurioids with: primary tubercles perforate and non-crenulate ambulacra with two occluded elements; pore-pairs arranged uniserially adorally with accessory plates at adradial suture oral tubercles large and with sunken areoles peristomial membrane with series of ambulacral plates spines simple, with sac-like gland at tip of aboral spines.
Range	Recent; worldwide.
Classification and/or Status	Euechinoidea, Echinothurioida
Remarks	Differentiated from Echinothuriidae by its simple oral spines lacking a hyaline hoof. Differs from Paraphormosoma in having primary elements in the triads in contact with the adradial suture and in having sunken areoles. Mortensen, T. 1934. New Echinoidea. (Preliminary Notice.) . Videnskabelige Meddelelser fra Danks naturhistorisk Forening i Kobenhavn 98, 161-167. Mortensen, T. 1935. A Monograph of the Echinoidea. II. Bothriocidaroida, Melonechinoida, Lepidocentroida, and Stirodonta. C. A. Reitzel, Copenhagen, 647 pp.