The Echinoid Directory

• Test ovate without anterior sulcus; posterior face truncate. Test depressed in profile.
• Apical disc ethmolytic with four gonopores; well anterior of centre; madrepores extend far behind posterior oculars.
• Anterior ambulacrum narrow and flush; pore-pairs small and undifferentiated.
• Paired ambulacra petaloid; petals narrow, parallel-sided and very weakly depressed. Anterior petals with anterior column of pores rudimentary in upper part. Posterior petals slightly longer and flexed outwards. Almost no interporal zone in petals.
• Peristome large and D-shaped.
• Labral plate short and wide, not extending beyond ambulacral plate 1. Sternal plates long and parallel-sided. Sternal-episternal suture curved (concave to posterior).
• Periproct on posterior truncate face.
• Subanal fasciole present; shield-shaped.
• Peripetalous fasciole present; narrow; weakly kinked behind anterior petals but not indented.
• Aboral tuberculation heterogeneous. Primary tubercles much more strongly developed in posterior column of lateral interambulacra and confined to within peripetalous fasciole.

Recent, Mediterranean.

Metalia costae Gasco, 1876, p. 4, by original designation.

• Only the type species.

Spatangoida, Micrasterina, Brissidae.

Monotypic; subjective junior synonym of Rhabdobrissus Cotteau, 1889.

Lambert (1923) established this genus and distinguished it from Metalia by the complete absence of a frontal groove, the non-confluent posterior petals and the restriction of tubercles to the posterior portion of the lateral interambulacra. A good description of the type species is to be found in Mortensen (1913).

Lambert, J. 1923 (July). Mem. Acad. Aube 85, p. 44.

Mortensen, T. 1913. Die Echiniden des Mittelmeeres, eine revidierte Ubersicht der im Mittelmeere lebenden Echiniden, mit Bemerkungen uber neue oder weniger bekannte Formen. Mitteilungen aus der Zoologischen Station zu Neapel 21, 1-40 pls 1-5.