The Echinoid Directory

• Test depressed, flattened above and below.
• Apical disc small (about one-quarter test diameter; plates often preserved bound to corona; monocyclic, with large, smoothly rounded, subcircular periproct.
• Ambulacra straight, relatively wide. Plating polygeminate with 5 elements. Pore-pairs uniserial, in arcs throughout; no phyllodes. Plate compounding with an echinid triad and an overlapping primary tubercle, alternating with one or two simple elements.
• Large primary tubercle on each compound ambulacral plate; small dense secondary tubercles and granules perradially.
• Interambulacral plates much wider than tall, with large, centrally placed primary tubercle. Adradial and interradial zones of dense uniform secondaries and granules.
• Primary tubercles imperforate and crenulate.
• At ambitus and adapically small pits and elongate sutural depressions developed giving the test a sculpted appearance.
• Peristome moderately large, weakly sunken, with well defined buccal notches that are rimmed.
• No sphaeridial pits; no basicoronal plate.
• Lantern and spines unknown.

Upper Cretaceous, North Africa.

Cyphosoma delamarrei Desmarest, in Agassiz & Desor, 1846, p. 361, by subsequent designation of Lambert & Thiery, 1911, p. 221.

• R. delamarrei (Deshayes, 1847); Santonian, North Africa.

Euechinoidea, Camarodonta, Glyphocyphidae.

Monotypic

Very close to Glyphocyphus but differing in having imperforate tubercles and polygeminate ambulacra with an echinid-style triad core.