The Echinoid Directory

• Test large and relatively thin plated; adambulacral suture appears to be imbricate.
• Apical disc and aboral surface unknown.
• Interambulacra with 7-8 plates in a series to the ambitus (estimated 12-16 in total). Primary tubercles perforate and crenulate; areoles ovate and confluent over entire oral surface.
• Scrobicular tubercles undifferentiated; adradial and interradial bands of secondary tubercles.
• Ambulacra narrow and straight. Pore zones not incised; pore-pairs not conjugate with narrow interporal ridge. Ambulacra trigeminate Every third plate enlarged and with a primary tubercle, other plates reduced and with secondary tubercles only. Primary ambulacral tubercles perforate.
• Peristomial plates well developed, in double series in each column.
• Lantern with grooved teeth; perignathic girdle not seen.
• Primary spines long and cylindrical; neck moderately long; shaft smooth and glassy.
• Secondary spines not flattened, not adpressed.

Lower Jurassic; Europe; ? Upper Triassic, New Zealand.

Cidaris edwardsi Wright, 1858, p. 26, by subsequent designation of Mortensen, 1928, p. 482.

• P. edwardsi (Wright, 1858); Pliensbachian, England.
• P. lobatum (Wright, 1878); Hettangian, Sinemurian, England.

Other species may belong here but are incompletely known and are basically indeterminate

• ?P. moraldina (Cotteau, 1849); Pliensbachian, France.
• ?P. denticulata Fell, 1950; Carnian, New Zealand.

Cidaroida; stem group (miocidarids).

?

Distinguished by its perforate primary ambulacral tubercles and smooth primary spines.

Pomel, A. 1883. Classification methodique et genera des echinides vivants et fossiles. Thesis presentees a la Faculte des Sciences de Paris. A. Jourdan, Alger, 131 pp.