TY  - CHAP
AB  - Recent Lithonida (Calcarea, Calcaronea) contains two families of Calcaronea characterized by a hypercalcified skeleton, which is reinforced either by the linkage of tetractines or by the formation of a rigid basal mass of calcite. The living tissue has free calcareous spicules, most frequently including tuning-fork triactines, or diapasons. They appear as survivors of fossil ‘pharetronids’, a polyphyletic grouping of fossil calcareous sponges, and are presently restricted to submarine caves and to bathyal rocky environments. The fossil genera are not treated here.
A1  - Vacelet, J.
A1  - Borojevic, R.
A1  - Boury-Esnault, N.
A1  - Manuel, M.
DO  - 10.1007/978-1-4615-0747-5_121
N1  - The PDF supplied here is a proof - NOT the definitive printed text - of a chapter of the Systema Porifera
C1  - ISBN 0-36-47260-0 (printed version)
TI  - Order Lithonida Vacelet, 1981, Recent. Pp. 1185-1192.  <i>In</i>: Hooper, J.N.A. & Van Soest, R.W.M. (eds)<i> Systema Porifera. A guide to the classification of sponges</i>. (2 volumes) Kluwer Academic/ Plenum Publishers: New York, 1708 + xlviii
UR  - https://www.marinespecies.org/aphia.php?p=sourcedetails&id=9094
PY  - 2002
Y2  - 2026-07-20
ER  -