Paraleucilla Dendy, 1892

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 : 239-240

Genus Paraleucilla Dendy, 1892

TYPE SPECIES. — Leucandra cucumis Haeckel, 1872 by monotypy.

DIAGNOSIS. — Amphoriscidae with a leuconoid organization. The thick wall is divided into two regions. The outer region is supported by the skeleton which remains essentially inarticulate, with the apical actines of cortical tetractines pointed inwards, and a layer of triactines and/or tetractines with the unpaired actine

cx st

pointed outwards. The inner region of the choanoskeleton is intercalated between the original subatrial skeleton and the atrial one, and it is supported by large triactines and/or tetractines, that are scattered in disarray, and whose form is similar to the spicules found in the outer layer of the choanoskeleton, or inside the atrial skeleton. Since the original subatrial layer still remains in the outer part of the choanosome, facing the cortical tetractines, there are no typical subatrial spicules adjacent to the atrial skeleton.

DESCRIPTION

Some leuconoid Amphoriscidae are massive sponges, with a folded, and thickened body. In these cases, the inarticulate organization is retained only in the outermost layer of the choanosome, which has a typical inarticulate skeleton consisting of the apical actines of cortical tetractines. Subatrial triactines or tetractines maintain their original position with their unpaired angle directed towards the atrium and their unpaired actine pointed towards the cortex ( Fig. 35). The

cx st pt

sl

as a

latter spicules, however, are far from the surface of the atrium or larger exhalant canals, since a thick layer supported by numerous scattered irregular triactines and/or tetractines is intercalat- ed in between. This inner layer never has any traces of a radial structure, and is clearly a new acquisition due to the intense growth of the sponge in this region. This structure had been well-described in Leucandra cucumis Haeckel, 1872 , but the outermost inarticulate layer was erroneously interpreted as containing only inhalant cavities. In specimens that we have observed, the outer layer contains the choanosome, although the lack of scattered spicules, that are present in the inner part of the wall gives an impression of loose cavities.

Dendy (1892b) proposed the genus Paraleucilla for Haeckel’s species Leucandra cucumis . He afterwards abandoned this idea and included the species in the genus Leucilla (Dendy, 1893) , but subsequently returned to use the genus (Dendy & Row 1913) in order to underline the particular organization of the subcortical region. After examination of the material listed below, we have found that other sponges classified in the genus Leucilla showed the organization typical of Paraleucilla in which we now classify them: Paraleucilla (Leucilla) saccharata Haeckel, 1872 , (material studied MNHN-LBIM-C1968-681; BMNH 86.6.7.64 and 25.11.1.690a), Paraleucilla (Leucilla) crosslandi Row, 1909 (material studied BMNH 1954.2.24.25), Paraleucilla (Leucilla) proteus Dendy, 1913 (material studied BMNH 20.12.9.60a), Paraleucilla (Leucilla) princeps Row & Hôzawa, 1931 (material studied BMNH 25.11.1.90a).