The Echinoid Directory

• Test relatively thick and depressed.
• Apical disc 40-50% of test diameter; all genital plates similar in size; oculars generally insert. Plates rather densely covered in tubercles.
• Interambulacra with up to 10 plates in a series. Primary tubercles perforate and effectively non-crenulate (adapical tubercles may retain traces of crenulation). Areoles circular and incised. Areoles separated on all but the most adoral plates.
• Scrobicular tubercles differentiated. Extrascrobicular zones narrow; secondary tubercles rather small and sparse. Sutures incised.
• Ambulacral zones weakly sinuous. Pore zones hardly incised. Pore-pairs subconjugate, the interporal zone not much broader than a single pore. Perradial zone with marginal series of small tubercles and single much smaller inner secondary tubercle; broad naked central band.
• Peristome a little smaller than the apical disc. Ambulacral series uniserial, interambulacral series just reaching the mouth.
• Primary spines long and slender with short neck and collar. Shaft ornamented with finely thorned ribs, the thorns asymmetrically developed around the circumference. Oral spines not distinctly serrated.
• Secondary spines adpressed.

Recent, Caribbean and Atlantic.

Dorocidaris bartletti Agassiz, 1880, p. 69, by original designation.

• T. bartletti (Agassiz, 1880); Recent, Caribbean.
• T. spinosa Mortensen, 1903; Recent, Atlantic.
• see also species listed under T. (Stylocidaris).

Cidaroida, Cidaridae, Cidarinae.

Distinguished from Cidaris by having a rather naked perradial zone, and subconjugate pore-pairs. It also differs in having a much more pentagonal outline to the apical disc.

Clark, H. L. 1909. The Cidaridae. Bulletin of the Museum of Comparative Zoology at Harvard College 51(7), 165-230, pls 1-11.

Mortensen, T. 1903. Danish Ingolf Expedition 4 (1) Echinoids.

Mortensen, T. 1928. A monograph of the Echinoidea. 1, Cidaroidea. C. A. Reitzel, Copenhagen.