The Echinoid Directory

Lenicyamidia Brunnschweiler, 1962, p. 165

Diagnostic Features
  • Small, lentil-shaped test up to 10 mm in length. Ovate in outline and with thick, rounded margin.
  • Apical disc central with four gonopores; monobasal.
  • Petals small but distinct; pore-zones parallel and open distally.
  • Ambulacral zones very slightly wider than interambulacral zones at ambitus.
  • Peristome central with small rim.
  • No food grooves.
  • Periproct opening on oral surface near posterior margin; at contact between the first and second pairs of post-basicoronal plates.
  • In basicoronal circlet interambulacral plates not projecting much beyond ambulacral plates.
  • Tubercles on oral surface bilaterally arranged leaving broad naked sagittal zone. Primary tubercles confined to the lateral margins.
  • No internal partitions.
Distribution
Eocene, western Australia.
Name gender feminine
Type
Lenicyamidia compta Brunnschweiler, 1962, by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Clypeasteroida; Scutellina; Laganiformes; Fibulariidae.

Monotypic.

Remarks

Like Lenita in having a distinct bilateral symmetry to its oral tuberculation but differing from that genus in having an oral rather than aboral periproct. Leniechinus differs from Lenicyamidia in having radial partitions developed internally. The apical disc was originally shown as tetrabasal, but Philip (1966) pointed out that this was wrong and that the disc was monobasal. The bare sagittal zone on the oral surface distinguishes this genus from all other Fibulariidae.

Brunnschweiler, R. O. 1962. On echinoids in the Tertiary of western Australia with a description of two new Eocene Fibulariidae. Journal of the Geological Society of Australia 18, 159-169.

Philip, G. M. 1966. Notes on three recently proposed Australian Tertiary echinoid genera. Proceedings of the Linnean Society of New South Wales 91, 114-117.