Leucilla Haeckel, 1872

Borojevic, Radovan, Boury-Esnault, Nicole & Vacelet, Jean, 2000, A revision of the supraspecific classification of the subclass Calcaronea (Porifera, class Calcarea), Zoosystema 22 (2), pp. 203-263 : 239

Genus Leucilla Haeckel, 1872

TYPE SPECIES. — Leucilla amphora Haeckel, 1872 by subsequent designation (Dendy & Row 1913).

DIAGNOSIS. — Amphoriscidae with a sylleibid or leuconoid organization. The choanoskeleton is formed primarily by the apical actines of giant cortical triactines and the unpaired actines of subatrial triactines or tetractines. It may contain dispersed spicules, but a typical articulate choanoskeleton is always absent.

DESCRIPTION

The genus Leucilla is quite close to Amphoriscus , and most species have a sylleibid aquiferous system. The simple species of Leucilla , such as L. amphora Haeckel, 1872 , always have a thin sponge wall and an inarticulate choanoskeleton, which is reduced to the apical actines of cortical tetractines and to the unpaired actines of subatrial triactines or tetractines ( Fig. 34 ). In specimens of Leucilla that build a thicker wall, scattered triactines or tetractines can be found in the choanosome, but they clearly derive from the cortical or the subatrial skeleton. There is no primary choanoskeleton derived from radially arranged spicules, and Leucilla species have never any structures reminiscent of the articulate arrangement of the choanoskeleton.

A group of sponges that have the organization typical of Leucandra , has been described under the genus Leucilla . Tetractines are present in their cortical skeleton, but their apical actines do not represent the main support of the choanoskeleton, which is typically articulate and clearly reminiscent of a grantiid organization with many rows of choanosomal triactines. Dendy & Row (1913) placed them in the genus Leucandra and we now include these sponges in the genus Leucandrilla .

Figures

FIG. 34. — Diagram of a transverse section through the wall of Leucilla. Abbreviations: a, atrium; as, atrial skeleton; ss, subatrial spicule; st, subcortical tetractines; cx, cortex.